Distribution modelling and multi-scale landscape connectivity highlight important areas for the conservation of savannah elephants Biol. Conserv. (IF 4.022) Pub Date : 2018-05-26 Daniel Zacarias, Rafael Loyola
Habitat connectivity is the milestone towards species' long-term persistence, especially considering impacts of climate change and human activities. Here, we examined the potential implications of climate change and human pressure on connectivity among habitat patches, aiming to identify priority areas and potential corridors for elephant conservation. We used an ensemble modelling approach to evaluate the potential climatic distribution of the savannah elephants Loxodonta africana through time. We considered different climatic scenarios and used current potential climatic suitability and human pressure to evaluate habitat quality for the species. In addition, we used habitat quality and the centroids of elephant patches to evaluate habitat connectivity considering four progressive dispersal distances (100 km, 200 km, 300 km, 400 km). Elephant response to climate change has been conservative through time with overall slight improvement in climatic suitability in southern and eastern Africa and reduction in western Africa and northern portions of central Africa. Habitat quality followed the distribution of currently suitable areas for the species. We found three major areas with high density of least-cost paths in southern, eastern and western Africa, identifying them as potential areas for increasing the connectivity of elephant populations.
Adaptive management of ecological systems under partial observability Biol. Conserv. (IF 4.022) Pub Date : 2018-05-26 Milad Memarzadeh, Carl Boettiger
Adaptive management has a long history in ecology and conservation. Uncertainty in both the state of a system and the model defining its dynamics are fundamental challenges in adaptive management of complex ecological systems. Traditional approaches in conservation biology often ignore one or both sources of uncertainty due to the computational complexity involved. Here, we show that underestimating the role of uncertainty in both model estimation and decision-making results in aggressive decision rules which can potentially lead to the dramatic decline and possible collapse of a population, species, or ecosystem. We propose an approximate solution to adaptive management of ecological systems under both model and state uncertainties that is computationally feasible and applicable to complex management problems and provide a software for detailed implementation of our method, http://doi.org/10.5281/zenodo.1161521. We apply the proposed method in a marine ecosystem management context and show that by learning from historical data and arrival of new observations, decision makers can adapt their policies to avoid decline in the population and reach a sustainable population stability.
Multi-species occupancy modelling of mammal and ground bird communities in rangeland in the Karoo: A case for dryland systems globally Biol. Conserv. (IF 4.022) Pub Date : 2018-05-26 Marine Drouilly, Allan Clark, M. Justin O'Riain
The transition from natural habitat to agricultural land use is widely regarded as one of the leading drivers of biodiversity loss. Despite this, most wildlife still lives outside protected areas on private agricultural land, particularly on rangeland used for livestock grazing. Understanding which species persist and which decline in agricultural landscapes is important for global biodiversity monitoring, management and conservation. In this study, we used hierarchical multi-species occupancy modelling to estimate terrestrial vertebrate (body mass > 0.5 kg) richness in the Karoo, a semi-arid region of South Africa. We evaluated species-specific responses to different anthropogenic and environmental variables in rangeland and a nearby protected area of similar size. We grouped mammal species according to trophic guild and body size and compared their occurrence between areas. In total we detected 42 species over 4035 6-day pooled trap nights across 322 sites. Community species richness was not significantly different between the two types of land use and decreased with increasing elevation in the protected area. Human disturbance did not affect individual species occupancy in either area. Carnivores, omnivores and medium-sized species occupancy probabilities were similar between the two areas but were higher for herbivores and large species in the protected area and for insectivores and small species in rangeland. Our results reveal that drylands in the South African Karoo region, including rangeland used for small-livestock farming, support a diverse community of terrestrial vertebrates. Private landowners are thus important custodians of key components of indigenous biodiversity outside of protected areas, especially in low-lying areas.
Do United States protected areas effectively conserve forest tree rarity and evolutionary distinctiveness? Biol. Conserv. (IF 4.022) Pub Date : 2018-05-26 Kevin M. Potter
Because forest tree species face serious threats including insect and disease epidemics, climate change, and forest fragmentation and conversion, prioritizing species and forests for conservation is an essential management goal. This paper describes a species prioritization approach that incorporates both the rarity of species, because of the increased vulnerability associated with rare species, and their evolutionary distinctiveness (ED), a measure of evolutionary originality. Rarity and ED scores, and scores for the two combined, were calculated for 352 North American forest tree species. A weak but significant phylogenetic signal was associated with species rarity. The scores were used to weight species importance values on approximately 130,000 forest inventory plots across the conterminous United States. The resulting plot-level estimates of conservation value were employed to identify geographic hotspots of forests with high conservation value, and to assess whether forests with protected status effectively conserve rarity and ED. Rarity hotspots were detected in California, the Southwest, central Texas, and Florida. Hotspots of ED included locations along the Pacific Coast, in the Northern Rockies, and in scattered eastern locations. Protected forest areas across the United States effectively conserve ED, but not rarity. In fact, rarity was lowest in areas with the highest protection, and highest in areas with no or unknown protected status. Multiple-use protected areas had higher ED, but not rarity, than restricted-use protected areas. Protected area effectiveness varied across the country. Such spatially explicit assessment approaches can help determine which forests to target for monitoring efforts and pro-active management activities.
Automated monitoring for birds in flight: Proof of concept with eagles at a wind power facility Biol. Conserv. (IF 4.022) Pub Date : 2018-05-26 Christopher J.W. McClure, Luke Martinson, Taber D. Allison
Automated surveys for wildlife have the potential to improve data collection while averting mortality of animals. Collisions of eagles at wind power facilities are particularly of concern and therefore an automated system that could detect birds, determine if they are eagles, and track their movement, might aid in curtailing wind turbines before collisions occur. Here, we use human observers and photographs to test the ability of a camera-based monitoring system, called IdentiFlight, to detect, classify, and track birds. IdentiFlight detected 96% of the bird flights detected by observers and detected 562% more birds than did observers. The discrepancy between observers and IdentiFlight seemed to be because the ability of observers to detect birds declined sharply by distance and toward the west. We reviewed photographs taken by IdentiFlight and determined that IdentiFlight misclassified nine of 149 eagles as non-eagles for a false negative rate of 6%, and 287 of 1013 non-eagles as eagles for a false positive rate of 28%. The median distance at classification for birds classified as eagles was 793 m and the median time from detection till classification was 0.4 s. Collectively, our results suggest that automated cameras can be effective means of detecting birds in flight and identifying eagles.
Identification of marine key areas across the Caribbean to ensure the conservation of the critically endangered hawksbill turtle Biol. Conserv. (IF 4.022) Pub Date : 2018-05-22 Manon Nivière, Philippine Chambault, Thierry Pérez, Denis Etienne, Marc Bonola, Jordan Martin, Cyrille Barnérias, Fabien Védie, Julien Mailles, Émilie Dumont-Dayot, Julie Gresser, Gaëlle Hiélard, Sidney Régis, Nicolas Lecerf, Laurent Thieulle, Matthieu Duru, Fabien Lefebvre, Guillaume Milet, Blandine Guillemot, Bernard Bildan, Benjamin de Montgolfier, Abdelwahab Benhalilou, Céline Murgale, Thomas Maillet, Patrick Queneherve, Thierry Woignier, Morjane Safi, Yvon Le Maho, Odile Petit, Damien Chevallier
Acquisition of data on animal movement when developing management strategies is a common challenge in species conservation, especially when dealing with a critically endangered species as the hawksbill turtle Eretmochelys imbricata. To reach the objective of the 2008 national action plan for Martinique Island (French West Indies), the present paper examines horizontal and vertical movements in juveniles (n = 3) and adults life stages (11 females and 2 males) of 16 hawksbill turtles. Our results reveal the strong site fidelity of individuals to their foraging grounds (mean male foraging home range: 89.3 ± 20.2 km2, mean female foraging home range: 336 ± 284.7 km2, mean juvenile foraging home range: 157.3 ± 71.2 km2) and to the females' inter-nesting areas (mean home range: 284.2 ± 523.7 km2). A spatial foraging overlap occurred between juveniles and males as they shared 41% of their 95% kernel foraging habitat. The turtles performed mainly long and shallow dives within the first 20 m deep around Martinique Island, occupying shallow waters close to shore. The migratory routes of the adult females revealed regional connectivity between the Caribbean islands, crossing 31 exclusive economic zones and international waters, and featuring distinct foraging grounds. This finding reinforces the significance of a cooperative network at the Caribbean scale to ensure the efficient conservation of this critically endangered species.
Can trackers count free-ranging wildlife as effectively and efficiently as conventional aerial survey and distance sampling? Implications for citizen science in the Kalahari, Botswana Biol. Conserv. (IF 4.022) Pub Date : 2018-05-14 Derek Keeping, Julia H. Burger, Amo O. Keitsile, Marie-Charlotte Gielen, Edwin Mudongo, Martha Wallgren, Christina Skarpe, A. Lee Foote
Estimating wildlife abundance is central to conservation. We compared two widely practiced standards for counting animals - aerial strip surveys and ground line transects - with interpreted counts of animal tracks. At equal sampling intensity in semiarid savanna with good visibility all three methods produced similar population estimates and precision for six large herbivores. This comparison adds empirical support for the use of track count data to estimate population density rather than being restricted to ambiguous indices of relative abundance. Although expected to capture more species than aerial surveys, we found line transects limiting because encounter rates by direct sightings were relatively low; a minimum threshold 40 observations was achieved for only 1/3 of antelope species in 648.4 km of transect. By contrast, animal track counts returned exceedingly high encounter rates that allowed estimation of abundance for the entire large predator-prey community and mapping density-distributions more completely. Unlike aerial surveys conducted by Botswana's wildlife authority, the track survey provided opportunity to involve local people in the research process. The track survey cost 40% less than the aerial survey, and could be reduced a further 3-fold if trackers collected data autonomously without motor vehicles. Counting animals by their tracks is ultimately constrained to regions with appropriate substrates. However, in suitable environments like the Kalahari, we suggest that a citizen science driven by expert local trackers could ultimately replace conventional wildlife counts, generating knock-on benefits to conservation beyond improved data.
Parks protect forest cover in a tropical biodiversity hotspot, but high human population densities can limit success Biol. Conserv. (IF 4.022) Pub Date : 2018-05-13 Meghna Krishnadas, Meghna Agarwala, Sachin Sridhara, Erin Eastwood
Maintaining forest cover is important for Biodiversity Hotspots that support many endangered and endemic species but have lost much of their original forest extent. In developing countries, ongoing economic and demographic growth within Hotspots can alter rates and patterns of deforestation, making it a concern to quantify rates of forest loss and assess landscape-scale correlates of deforestation within Hotspots. Such analyses can help set baselines for future monitoring and provide landscape-scale perspectives to design conservation policy. For the Western Ghats Biodiversity Hotspot in India, we examined correlates of forest loss following rapid economic expansion (post-2000 CE). First, we used open-source remote-sensing data to estimate annual trends in recent forest loss (from 2000 to 2016) for the entire Hotspot. Across the entire Western Ghats, we assessed the relative importance of and interactions among demographic, administrative, and biophysical factors that predicted rates of forest loss—measured as the number of 30 × 30-m pixels of forest lost within randomly selected 1 km2 cells. Protected areas reduced forest loss by 30%, especially when forests were closer to roads (33%) and towns (36%). However, the advantage of protection declined by 32% when local population densities increased, implying that the difference in forest loss between protected and non-protected areas disappears at high local population densities. To check scale-dependency of spatial extent, we repeated the modelling process for two landscape subsets within Western Ghats. In contrast with results for the entire Western Ghats, both focal landscapes showed no difference in deforestation with protection status alone or its interactions with village population density and distance to towns. However, deforestation was 88% lower when forests were protected and farther from roads. Overall, our results indicate that protected areas help retain forest cover within a global Biodiversity Hotspot even with rapid development, but high human population densities and road development can reduce the benefits of protection.
Somewhere between acceptable and sustainable: When do impacts to resources become too large in protected areas? Biol. Conserv. (IF 4.022) Pub Date : 2018-05-13 Scott Gende, A. Noble Hendrix, Joshua Schmidt
Utilization of marine and terrestrial protected areas is fundamentally important for their acceptance and success. Yet even appropriate uses can negatively impact resources requiring managers to make decisions as to when the impacts become unacceptably large. These decisions can be difficult because the level at which impacts occur may be far below the level at which resource persistence is threatened. In Glacier Bay National Park, Alaska, managers must make a recurring decision regarding the number of cruise ships that are allowed to enter the park each year. Cruise ships bring >95% of all visitors to the park but have been involved in several lethal collisions (ship strikes) with humpback whales. Using an individual-based simulation model, we demonstrate that increasing the annual ship volume from current to maximum allowable levels would have negligible impacts on population growth of whales. Over the next 30 years the median number of collisions would likely increase from 3 (95% CI: 0–7) to 4 (1–8) or, worst case scenario, from 5 (0–7) to 8 (3−13), while median annual growth rates would, at most, shift from 4.4% (3.7%–5.2%) to 4.2% (3.5%–4.9%), depending upon assumptions. By comparison, a median of 67 (50–82) ship strikes would need to occur over the next 30 years to threaten the persistence of whales. Confronted with an impact level that is far below what would threaten the conservation of whales, managers are tasked with the decision of placing values on 2 million additional visitors for every additional dead whale. We argue that decision-making related to use-impact trade-offs for protected areas could be more consistent and effective if site-values are defined explicitly, clearly communicated among stakeholders, and linked to biological metrics. Protected areas managers can then utilize monitoring programs to evaluate management effectiveness when the objective is conserving both resources and values.
Have Indo-Malaysian forests reached the end of the road? Biol. Conserv. (IF 4.022) Pub Date : 2018-05-12 Alice C. Hughes
The Indo-Malaysian region harbours some of the highest diversity globally, yet it is also has the highest rates of deforestation. Furthermore some countries have shown up-to a 10 times increase in the area deforested annually between 2001 and 2014. Large-scale forest clearance is preceded by the growth of road networks which provide a stark warning for the region's future as many of the roads established for clearance or infrastructure are illegal and unmapped. In some regions almost 100% of roads were previously unmapped on the global roads map, yet 99.9% of deforestation occurs within 2.5 km of these roads. In Borneo the majority of plantations are on an industrial-scale averaging over 10 km2 in size, whereas most of the region typically has plantations under 1 km2 integrated into a landscape mosaic, though the preliminary infrastructure for industrial plantations are being developed in parts of the region. Within the coming decade most of the region may lose almost all unprotected forests. As some countries have only 2% of their land-area protected this condemns many of the regions endemic species to extinction. Urgent measures are needed to protect a much larger proportion of remaining forest, as this offers the only means to protect many of the regions endemic species.
Old growth, regrowth, and planted woodland provide complementary habitat for threatened woodland birds on farms Biol. Conserv. (IF 4.022) Pub Date : 2018-05-11 Karen Ikin, Ayesha I.T. Tulloch, Dean Ansell, David B. Lindenmayer
A central challenge for threatened species conservation in agricultural landscapes is to understand the relative contributions of old growth, regrowth, and planted woodland to species persistence. We offer a new perspective into solving this problem by using a systematic conservation planning approach to integrate spatial biodiversity and economic information with patch complementarity. We applied this to an eight-year study of woodland birds vulnerable to extinction across an extensive agricultural region of Australia. We used regression and ordination analyses to show that species were more likely to occur in regrowth and old growth woodland patches compared with plantings. We then set objectives of finding sets of complementary patches for supporting species across the landscape, and explored biodiversity trade-offs resulting from production- or cost-focused objectives. We found that species persistence could be achieved only through sets of patches containing all patch types (old growth, regrowth, plantings). Scenarios that selected sets of patches irrespective of patch type maximized species occurrence over time for the lowest combined area and establishment costs. Patch sets had a higher proportion of plantings for the objective of minimizing area, but a more equal proportion of patch types for the objective of minimizing cost. Our findings demonstrate what the relative composition of old growth, regrowth, and plantings should be when considering vegetation management interventions for threatened species conservation. Government policy and associated funding aimed at improving biodiversity conservation in agricultural landscapes needs to promote both regrowth woodland and revegetation planting strategies in addition to old growth woodland protection.
Uncontrolled hunting and habitat degradation decimate and extirpate forest hornbills in Ghana, West Africa Biol. Conserv. (IF 4.022) Pub Date : 2018-05-11 Lars H. Holbech, Nathaniel N.D. Annorbah, Ben Phalan, Nico Arcilla
Tropical forests are on the front lines of the current global extinction crisis. Species with restricted habitat requirements and slow reproductive rates, such as the spectacular hornbills (Bucerotidae) of the Paleotropics, are particularly vulnerable. We present the first long-term quantitative population assessment of nine forest hornbill species in Ghana, part of the Upper Guinea forest biodiversity hotspot in West Africa. From 1990 to 2009, hornbill encounter rates declined with 32–88% across eight species found in the region. Seven separate surveys between 1990 and 2014 indicated declines in at least six of eight species detected, with large-bodied species hardest hit. Depleted remnant populations of large hornbills mainly persist in two large and relatively well-protected wildlife reserves, Ankasa Resource Reserve and Kakum National Park. Contrastingly, the five largest species of the nine hornbills known to Bia Biosphere Reserve, one of Ghana's few forest wildlife reserves, apparently vanished completely since the 1990s, mainly due to uncontrolled hunting. Similarly, several large hornbills have disappeared from forest reserves where hunting is widespread. We conclude that uncontrolled hunting is the major driver of the recent drastic declines and population extirpations of large hornbills, while reductions in small insectivorous species may be related to extensive fragmentation and habitat disturbances of the Ghanaian forest biome. We call for urgent conservation action to prevent further declines and impending extirpations of forest hornbills and other wildlife in West Africa.
Ecological neighborhoods as a framework for umbrella species selection Biol. Conserv. (IF 4.022) Pub Date : 2018-05-11 Erica F. Stuber, Joseph J. Fontaine
Umbrella species are typically chosen because they are expected to confer protection for other species assumed to have similar ecological requirements. Despite its popularity and substantial history, the value of the umbrella species concept has come into question because umbrella species chosen using heuristic methods, such as body or home range size, are not acting as adequate proxies for the metrics of interest: species richness or population abundance in a multi-species community for which protection is sought. How species associate with habitat across ecological scales has important implications for understanding population size and species richness, and therefore may be a better proxy for choosing an umbrella species. We determined the spatial scales of ecological neighborhoods important for predicting abundance of 8 potential umbrella species breeding in Nebraska using Bayesian latent indicator scale selection in N-mixture models accounting for imperfect detection. We compare the conservation value measured as collective avian abundance under different umbrella species selected following commonly used criteria and selected based on identifying spatial land cover characteristics within ecological neighborhoods that maximize collective abundance. Using traditional criteria to select an umbrella species resulted in sub-maximal expected collective abundance in 86% of cases compared to selecting an umbrella species based on land cover characteristics that maximized collective abundance directly. We conclude that directly assessing the expected quantitative outcomes, rather than ecological proxies, is likely the most efficient method to maximize the potential for conservation success under the umbrella species concept.
Worldwide increase in Artificial Light At Night around protected areas and within biodiversity hotspots Biol. Conserv. (IF 4.022) Pub Date : 2018-05-09 Adrien Guetté, Laurent Godet, Martin Juigner, Marc Robin
Artificial Light At Night (ALAN) has several adverse impacts on biodiversity, and it has been recently used as a proxy to monitor human encroachment on landscapes at large spatial scales. The extent to which ALAN affects protected areas (PAs) and biodiversity hotspots (BHs) remains however untested at large spatial scales. We used this proxy to assess the spatial and temporal trends in the anthropization at a global scale within and around PAs and BHs. We found that ALAN is low and stable over time within PAs, but is the highest in a first outer belt (<25 km) around PAs, and tends to increase in a second outer belt (25–75 km). In the meantime, ALAN is higher within BHs than outside, and is even the highest and increasing over time in an inner belt, close to their periphery. Our results suggest that although PAs are creating safety zones in terms of ALAN, they tend to be more and more isolated from each other by a concentric human encroachment. In contrast, BHs are submitted to an increasing human pressure, especially in their inner periphery. Overall, we suggest integrating ALAN in large-scale conservation policies.
The contribution of scientific research to conservation planning Biol. Conserv. (IF 4.022) Pub Date : 2018-05-09 Louise Mair, Aileen C. Mill, Peter A. Robertson, Steven P. Rushton, Mark D.F. Shirley, Jon Paul Rodriguez, Philip J.K. McGowan
Conservation planning plays an instrumental role in facilitating progress towards biodiversity targets by providing practitioners with the tools required to allocate resources and implement actions. However, the utility of a burgeoning scientific literature to on-the-ground conservation has been questioned. Given such criticisms, and the lack of progress towards the global Aichi Biodiversity Targets, we aim to assess the contribution of scientific research to the field of conservation planning. We applied topic modelling to a body of literature consisting of 4471 articles pertaining to conservation planning published between 2000 and 2016. We quantified changes in topic popularity, and assessed the extent to which different topics were addressed within the same articles. We found that research into the status of species and habitats was most prevalent, the process of action planning received considerably less attention, and implementation attracted the least research of all. The scientific literature was thus dominated by biological rather than socio-political research, and furthermore showed a general lack of inter-disciplinary research, which is problematic given that ultimately it is the socio-political context that will determine the success of conservation efforts. The number of publications on implementation and monitoring declined over time, suggesting a waning interest in publishing evidence of plan effectiveness, and that limited efforts have been made to address the “implementation crisis”. We suggest that filling research gaps, through integration of the social sciences and placing greater value on evidence syntheses, would push scientific research towards greater applicability and help to provide the necessary information to achieve global biodiversity targets.
Use of an unmanned aerial vehicle (drone) to survey Nile crocodile populations: A case study at Lake Nyamithi, Ndumo game reserve, South Africa Biol. Conserv. (IF 4.022) Pub Date : 2018-05-07 Mohamed A. Ezat, Camille J. Fritsch, Colleen T. Downs
Observer bias and inexperience are challenging aspects of crocodile survey methods for determining population numbers and structure. Aerial surveys with either a helicopter or a fixed winged aircraft are generally preferred methods to ground surveys; however, the high cost of the former is a limiting factor. Recently unmanned aerial vehicles (UAVs) or drones have been proposed for surveys because of their potential of improving over traditional techniques of wildlife monitoring and as they have relatively lower costs. We investigated of the suitability of a UAV to determine numbers and structure of the Nile crocodile, Crocodylus niloticus, population during winter at Lake Nyamithi, Ndumo Game Reserve in South Africa. We used the UAV for eight flights covering ~132 ha. We also conducted a diurnal ground survey of crocodiles for comparison. Using the UAV, 287 crocodiles were identified and body length measured accurately for size class allocation whereas only 211 crocodiles were counted in the diurnal ground survey. Consequently, the UAV aerial survey recorded 26% more crocodiles. The potential of using UAVs to estimate crocodile population size and measure the total length (TL) of individuals accurately and precisely at a relatively low cost should improve management actions, enable monitoring of the crocodile populations annually and importantly avoid observer bias. Implications of this may facilitate improved crocodilian survey techniques.
Charismatic species of the past: Biases in reporting of large mammals in historical written sources Biol. Conserv. (IF 4.022) Pub Date : 2018-05-04 Sophie Monsarrat, Graham I.H. Kerley
Long-term biodiversity occurrence records are key to quantify long-term biodiversity patterns and trends and inform the conservation of threatened species, but they are strongly biased in terms of the species represented. This taxonomic bias, and its correlation to societal preferences, is well-identified in modern biodiversity datasets. However, it remains to be investigated, and its basis understood, in long-term occurrence datasets assembled from historical sources. Here we investigate taxonomic bias for 38 species of large terrestrial mammals using a dataset of 780 historical occurrence assembled from 16th to mid-19th century historical written sources in South Africa. We test if this bias is related to species' historical charisma, using a functional definition of non-human charisma, supported by anecdotes from the historical literature. We identify a strong taxonomic bias, with up to several order of magnitudes of difference in the likelihood of reporting between some species. Species' charisma alone explains 75% of the observed variance, the most charismatic species being largely over-reported. This is the first evidence of a positive relationship between taxonomic bias and charisma in a historical biodiversity dataset, within a homogeneous taxonomic group such as large terrestrial mammals. These results improve our understanding of the relationship between people and the large terrestrial fauna in historical times and suggest that species' charisma is a good predictor of taxonomic bias in long-term biodiversity datasets. This provides background for modern conservation by illustrating the durability of the charisma concept and of its relation with taxonomic bias, with implications for the representativeness of species in long-term conservation studies.
Assessing the aggregated risk of invasive crayfish and climate change to freshwater crabs: A Southeast Asian case study Biol. Conserv. (IF 4.022) Pub Date : 2018-05-04 Yiwen Zeng, Darren C.J. Yeo
Primary freshwater crabs represent a culturally and ecologically significant component of freshwater habitats globally that has a high percentage of threatened species. Invasive species (especially non-indigenous crayfish) and climate change are not only important standalone threats, but are also expected to compound existing threats (e.g., habitat loss/modification, pollution) and challenge the long-term survival of these decapod crustaceans. This study illustrates the importance of considering these two emerging and growing threats in conservation or management strategies by quantifying (via species distribution models) the individual and aggregated risks of these threats in Southeast Asia, a region with the highest diversity of primary freshwater crabs and a high proportion of imperiled species. Results predicted that most species of crabs (82.1%) will co-occur (and hence interact) with invasive crayfish to a moderate to high degree, and most species (69.2%) will also experience a reduction in suitable climate conditions in the future. In terms of aggregated risk, the results also predict an increased overlap between invasive crayfish and native crabs for three out of the seven species analyzed (namely Procambarus virginalis, Cherax destructor and Orconectes rusticus). Findings from this study provide a quantitatively derived rationale for the development of adaptive regulations and conservation plans in the region to minimize the risk of invasive species in a cost-effective way, thereby enabling the protection of Southeast Asia's natural heritage and its vital ecosystem services.
Stream fish colonization but not persistence varies regionally across a large North American river basin Biol. Conserv. (IF 4.022) Pub Date : 2018-04-27 Kit Wheeler, Seth J. Wenger, Stephen J. Walsh, Zachary P. Martin, Howard L. Jelks, Mary C. Freeman
Many species have distributions that span distinctly different physiographic regions, and effective conservation of such taxa will require a full accounting of all factors that potentially influence populations. Ecologists recognize effects of physiographic differences in topography, geology and climate on local habitat configurations, and thus the relevance of landscape heterogeneity to species distributions and abundances. However, research is lacking that examines how physiography affects the processes underlying metapopulation dynamics. We used data describing occupancy dynamics of stream fishes to evaluate evidence that physiography influences rates at which individual taxa persist in or colonize stream reaches under different flow conditions. Using periodic survey data from a stream fish assemblage in a large river basin that encompasses multiple physiographic regions, we fit multi-species dynamic occupancy models. Our modeling results suggested that stream fish colonization but not persistence was strongly governed by physiography, with estimated colonization rates considerably higher in Coastal Plain streams than in Piedmont and Blue Ridge systems. Like colonization, persistence was positively related to an index of stream flow magnitude, but the relationship between flow and persistence did not depend on physiography. Understanding the relative importance of colonization and persistence, and how one or both processes may change across the landscape, is critical information for the conservation of broadly distributed taxa, and conservation strategies explicitly accounting for spatial variation in these processes are likely to be more successful for such taxa.
Modeling the fish community population dynamics and forecasting the eradication success of an exotic fish from an alpine stream Biol. Conserv. (IF 4.022) Pub Date : 2018-04-30 Christophe Laplanche, Arnaud Elger, Frédéric Santoul, Gary P. Thiede, Phaedra Budy
Management actions aimed at eradicating exotic fish species from riverine ecosystems can be better informed by forecasting abilities of mechanistic models. We illustrate this point with an example of the Logan River, Utah, originally populated with endemic cutthroat trout (Oncorhynchus clarkii utah), which compete with exotic brown trout (Salmo trutta). The coexistence equilibrium was disrupted by a large scale, experimental removal of the exotic species in 2009–2011 (on average, 8.2% of the stock each year), followed by an increase in the density of the native species. We built a spatially-explicit, reaction-diffusion model encompassing four key processes: population growth in heterogeneous habitat, competition, dispersal, and a management action. We calibrated the model with detailed long-term monitoring data (2001–2016) collected along the 35.4-km long river main channel. Our model, although simple, did a remarkable job reproducing the system steady state prior to the management action. Insights gained from the model independent predictions are consistent with available knowledge and indicate that the exotic species is more competitive; however, the native species still occupies more favorable habitat upstream. Dynamic runs of the model also recreated the observed increase of the native species following the management action. The model can simulate two possible distinct long-term outcomes: recovery or eradication of the exotic species. The processing of available knowledge using Bayesian methods allowed us to conclude that the chance for eradication of the invader was low at the beginning of the experimental removal (0.7% in 2009) and increased (20.5% in 2016) by using more recent monitoring data. We show that accessible mathematical and numerical tools can provide highly informative insights for managers (e.g., outcome of their conservation actions), identify knowledge gaps, and provide testable theory for researchers.
Unveiling the patterns and trends in 40 years of global trade in CITES-listed wildlife Biol. Conserv. (IF 4.022) Pub Date : 2018-05-02 Michael Harfoot, Satu A.M. Glaser, Derek P. Tittensor, Gregory L. Britten, Claire McLardy, Kelly Malsch, Neil D. Burgess
Wildlife trade can provide commercial incentives to conserve biodiversity but, if unsustainable, can also pose a threat. CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) aims to ensure international trade in CITES-listed species is sustainable, legal and traceable. However, large-scale temporal and spatial patterns in wildlife trade are poorly known. We address this by analysing the CITES Trade Database: >16 million shipment records for 28,282 species, from 1975 and 2014. Over this period, the volume of reported trade in CITES-listed wildlife quadrupled, from 25 million whole-organism equivalents per year to 100 million, and the ratio of wild- to captive-sourced trade in mammals, birds, reptiles, invertebrates and plants declined by an order of magnitude or more. Our findings start to reveal the scale of the legal wildlife trade, shifting trade routes and sources over time and we describe testable hypotheses for the causes of these changes.
Don't judge habitat on its novelty: Assessing the value of novel habitats for an endangered mammal in a peri-urban landscape Biol. Conserv. (IF 4.022) Pub Date : 2018-04-27 Sarah J. Maclagan, Terry Coates, Euan G. Ritchie
Novel ecosystems are increasingly common worldwide, particularly in areas heavily impacted by humans such as urban and peri-urban landscapes. Consequently, interest in their potential contribution to biodiversity conservation is growing, including their ability to sustain populations of threatened species. However, few studies have explored whether novel habitats can support viable populations over time and how they compare to less modified, remnant habitats. We investigated the capacity for novel habitats to support an endangered mammal, the southern brown bandicoot (Isoodon obesulus obesulus: Peramelidae), in a highly-modified landscape near Australia's second largest city, Melbourne. We compared bandicoot abundance and body condition between five novel and two remnant sites, and examined whether novel sites support residency and key demographic processes necessary for bandicoot population persistence. We found that bandicoot abundance was higher at novel than remnant sites, with the highest abundance at the novel site with the most urbanised surroundings. Female body condition was similar between novel and remnant sites. The majority of bandicoots at novel sites were resident, and breeding activity, recruitment of first-year adults, and survival of mature adults were observed at all novel sites. Our results demonstrate the potential significance of novel habitats for conserving threatened species within heavily-modified landscapes, and encourage us not to judge the quality of habitats on their novelty alone. Broadening our appreciation of the potential value of novel ecosystems could increase off-reserve species conservation opportunities, a key priority within the context of the Anthropocene and unprecedented global change and biodiversity loss.
Predicting population viability of the narrow endemic Mediterranean plant Centaurea corymbosa under climate change Biol. Conserv. (IF 4.022) Pub Date : 2018-04-28 Asma Hadjou Belaid, Sandrine Maurice, Hélène Fréville, David Carbonell, Eric Imbert
Climate change is a growing threat for global biodiversity, in particular for narrow endemic species. The Mediterranean region, which harbors an exceptional biodiversity, has been identified as one of the most sensitive regions to climate change. Based on a 22-year monitoring period, we analyzed the dynamic and viability of the six extant populations of a narrow endemic plant species of the Mediterranean area, Centaurea corymbosa, to predict their fate under two climatic scenarios. We constructed matrix projection models to calculate current asymptotic growth rates and to perform stochastic projections including both demographic and environmental stochasticity. Neither asymptotic growth rates nor their temporal variance were linked to population size and age at flowering. Randomization tests showed that asymptotic growth rates were significantly different among years but not among populations. An increase in temperature and a decrease in the number of wet days had a negative impact on the whole life-cycle, particularly in the summer period, and thus reduced asymptotic growth rates. Stochastic projections showed that an increased frequency of extreme climatic events increased population extinction risk and decreased mean time to extinction. The warm scenario had a more dramatic impact on population viability than the dry scenario. Management recommendations are proposed to increase population viability of endangered plant species such as C. corymbosa that face climate change.
Making sense of protected area conflicts and management approaches: A review of causes, contexts and conflict management strategies Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 Ophelia Soliku, Ulrich Schraml
Although it has been established that there is a strong geographical component to conflicts, previous studies on Protected Area (PA) conflicts have tended to focus on assessing the underlying causes of PA conflicts without considering how these conflicts vary across development contexts. Our review therefore assessed the similarities and differences that characterise PA conflicts in developing and developed countries with the view to drawing the implications of the findings for management practice. We reviewed a total of 65 publications from an initial pool of 516 drawn from biological, ecological, social sciences as well as an emerging interdisciplinary literature in conservation conflict studies from 1993 to 2016. Results of this literature review indicate that: 1) the types of PA conflict, why they occur, where they occur and how they are managed varied between developed and developing countries and were determined by geographical location and specific socio-economic and cultural contexts; 2) while PA conflicts in developing countries were primarily driven by impacts on livelihoods, PA conflicts in developed countries were driven by social considerations including emotional, recreational and cultural values people attached to PAs; and 3) conflict management strategies that promoted participation of other stakeholders including local people in PA management and provided economic incentives to local people promoted cooperation and fostered the meeting of conservation goals while conflict management strategies which employed deterrent strategies such as guards, fencing and policing especially in developing countries often resulted in resentment and sometimes led to the escalation of the conflicts. Conflict management strategies must therefore take into consideration the differences in the context within which conflicts develop at various locations to inform the specific conflict management strategies to be applied.
A review of searcher efficiency and carcass persistence in infrastructure-driven mortality assessment studies Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 Rafael Barrientos, Ricardo C. Martins, Fernando Ascensão, Marcello D'Amico, Francisco Moreira, Luís Borda-de-Água
Infrastructures in natural areas are expanding rapidly worldwide. Consequently, roads, power-lines, and wind-farms cause millions of fatalities across several animal groups. Assessing the population impact of these infrastructures requires sound estimates of the total number of fatalities. These estimates can be heavily biased due to differences in searcher efficiency and carcass persistence rates, which may ultimately lead to the incorrect quantification of actual mortality, or to the inadequate prioritization of locations for mitigation. We reviewed 294 studies using carcass surveys conducted worldwide and performed analyses on the effects of variables potentially influencing searcher efficiency and carcass persistence rates. Our analytical review, including the largest number of studies to date, the use of multivariate approaches, and the study weighting by sample size, contradicts some previous findings. Whereas body mass is confirmed as the most important variable accounting for both biases, equally important was the use of dogs in searches, as they increased searcher efficiency for small carcasses, and the taxon of carcasses for persistence, as mammals persisted at higher rates than birds and the latter at higher rates than amphibians. Our results provide little support for previous ideas on the influence of the use of domestic or thawed carcasses on persistence rates. Our findings contribute to synthesizing knowledge on the main factors affecting the two main mortality biases across carcass field experiments, and suggest recommendations for improving survey designs in future studies to minimize the biases identified.
Land-use change is associated with a significant loss of freshwater fish species and functional richness in Sabah, Malaysia Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 Clare L. Wilkinson, Darren C.J. Yeo, Heok Hui Tan, Arman Hadi Fikri, Robert M. Ewers
Global biodiversity is being lost due to extensive anthropogenic land cover change. In Southeast Asia, biodiversity-rich forests are being extensively logged and converted to oil-palm monocultures. The impacts of this land-use change on freshwater ecosystems, and particularly on freshwater biodiversity, remain largely understudied and poorly understood. We assessed the differences between fish communities in headwater stream catchments across an established land-use gradient in Sabah, Malaysia (protected forest areas, twice-logged forest, salvage-logged forest, oil-palm plantations with riparian reserves, and oil-palm plantations without riparian reserves). Stream fishes were sampled using an electrofisher, a cast net and a tray net in 100 m long transects in 23 streams in 2017. Local species richness and functional richness were both significantly reduced with any land-use change from protected forest areas, but further increases in land-use intensity had no subsequent impacts on fish biomass, functional evenness, and functional divergence. Any form of logging or land-use change had a clear and negative impact on fish communities, but the magnitude of that effect was not influenced by logging severity or time since logging on any fish community metric, suggesting that just two rounds of selective impact (i.e., logging) appeared sufficient to cause negative effects on freshwater ecosystems. It is therefore essential to continue protecting primary forested areas to maintain freshwater diversity, as well as to explore strategies to protect freshwater ecosystems during logging, deforestation, and conversion to plantation monocultures that are expected to continue across Southeast Asia.
British phenological records indicate high diversity and extinction rates among late-summer-flying pollinators Biol. Conserv. (IF 4.022) Pub Date : 2018-04-24 Nicholas J. Balfour, Jeff Ollerton, Maria Clara Castellanos, Francis L.W. Ratnieks
The long-term decline of wild and managed insect pollinators is a threat to both agricultural output and biodiversity, and has been linked to decreasing floral resources. Further insight into the temporal relationships of pollinators and their flowering partners is required to inform conservation efforts. Here we examined the phenology of British: (i) pollinator activity; (ii) insect-pollinated plant flowering; and (iii) extinct and endangered pollinator and plant species. Over 1 million records were collated from the historical databases of three British insect monitoring organisations, a global biodiversity database and an authoritative text covering the national flora. Almost two-thirds (62%) of pollinator species have peak flight observations during late-summer (July and August). This was the case across three of the groups studied: aculeate wasps (71% of species), bees (60%), and butterflies (72%), the exception being hoverflies (49%). When species geographical range (a proxy for abundance) was accounted for, a clear late-summer peak was clear across all groups. By contrast, there is marked temporal partitioning in the flowering of the major plant groups: insect-pollinated tree species blossoming predominantly during May (74%), shrubs in June (69%), and herbs in July (83%). There was a positive correlation between the number of pollinator species on the wing and the richness of both flowering insect-pollinated herbs and trees/shrubs species, per calendar month. In addition, significantly greater extinctions occurred in late-summer-flying pollinator species than expected (83% of extinct species vs. 62% of all species). This trend was driven primarily by bee extinctions (80% vs. 60%) and was not apparent in other groups. We contend that this is principally due to declines in late-summer resource supplies, which are almost entirely provisioned by herbs, a consequence of historical land-use change. We hypothesize that the seasonality of interspecific competition and the blooming of trees and mass-flowering crops may have partially buffered spring-flying pollinators from the impacts of historical change.
The threats endangering Australia's at-risk fauna Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 Adriana Allek, Ariadna S. Assis, Nicoli Eiras, Thais P. Amaral, Brooke Williams, Nathalie Butt, Anna R. Renwick, Joseph R. Bennett, Hawthorne L. Beyer
Reducing the rate of species extinctions is one of the great challenges of our time. Understanding patterns in the distribution and frequency of both threatened species and the threatening processes affecting them improves our ability to mitigate threats and prioritize management actions. In this quantitative synthesis of processes threatening Australian at-risk fauna, we find that species are impacted by a median of six threats (range 1–19), though there is considerable variation in numbers of threats among major taxonomic groups. Invasive species, habitat loss, biological resource use, natural systems modification and climate change are the processes most commonly affecting Australian threatened species. We identified an uneven distribution of research knowledge among species, with half of the total number of species-specific peer-reviewed scientific publications associated with only 11 threatened species (2.7%). Furthermore, the number of threats associated with each species was correlated with the research effort for that species, and research effort was correlated with body mass. Hence, there appears to be a research bias towards larger-bodied species, and certain charismatic species, that could result in inferences biased towards these favored species. However, after accounting for these effects we found that for birds, amphibians, reptiles and marine mammals body mass is positively correlated with the number of threats associated with each species. Many threats also co-occur, indicating that threat syndromes may be common.
Conservation conflicts: Behavioural threats, frames, and intervention recommendations Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 Zachary Baynham-Herd, Steve Redpath, Nils Bunnefeld, Thomas Molony, Aidan Keane
Conservation conflicts are widespread and are damaging for biodiversity, livelihoods and human well-being. Conflict management often occurs through interventions targeting human behaviour. Conservation interventions are thought to be made more effective if underpinned by evidence and a Theory of Change – a logical argument outlining the steps required to achieve goals. However, for conservation conflicts, the evidence and logic supporting different types of interventions has received little attention. Using conflict-related keywords, we reviewed trends in behavioural intervention recommendations across conflict contexts globally, as published in peer-reviewed literature. We developed typologies for conflict behaviours, intervention recommendations, and conflict frames and identified associations between them and other geographical variables using Pearson's Chi-squared tests of independence. Analysing 100 recent articles, we found that technical interventions (recommended in 38% of articles) are significantly associated with conflicts involving wildlife control and the human-wildlife conflict frame. Enforcement-based interventions (54% of articles) are significantly associated with conflicts over illegal resource use, while stakeholder-based interventions (37% of articles) are associated with the human-human conflict frame and very highly developed countries. Only 10% of articles offered “strong” evidence from the published scientific literature justifying recommendations, and only 15% outlined Theories of Change. We suggest that intervention recommendations are likely influenced by authors' perceptions of the social basis of conflicts, and possibly also by disciplinary silos.
Harvest portfolio diversification and emergent conservation challenges in an Alaskan recreational fishery Biol. Conserv. (IF 4.022) Pub Date : 2018-04-27 Anne H. Beaudreau, Maggie N. Chan, Philip A. Loring
Diversification of harvest portfolios can benefit resource users by providing increased flexibility to respond to regulatory, economic, and environmental pressures. These adaptations, while important for maintaining harvesting opportunities, can lead to conservation challenges by shifting effort to other species or habitats. Using semi-structured interviews with charter fishing captains (N = 52) and logbook data, we examined shifts in the diversity of target species portfolios in a major recreational fishery in Alaska over three decades. To understand the role of regulation in affecting what species charter captains choose to target, we contrasted harvest portfolios in communities from two regions with differing histories of regulation. Portfolio structure was dynamic, with the majority of respondents reporting changes in the number of harvested species, relative preference for different species, or both since the 1990s. Diversification emerged primarily as a result of increased retention of historically less-preferred species, such as rockfishes, sablefish, and Pacific cod. Patterns of rockfish retention in charter logbook data mirrored patterns in targeting reported by respondents. Southeast Alaska captains largely attributed portfolio diversification and shifts in species preferences to greater restrictions on harvest of a primary target species (Pacific halibut), while Southcentral Alaska captains identified shifting customer interests and declines in some target species as driving changes. Our findings suggest that avoiding unintended conservation impacts of single-species regulations requires broader recognition of the multispecies nature of recreational fishing in management. Understanding fisher behaviors, values, and motivations is essential, so that managers may better anticipate the responses of fishers to new regulations.
Combining global tree cover loss data with historical national forest cover maps to look at six decades of deforestation and forest fragmentation in Madagascar Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 Ghislain Vieilledent, Clovis Grinand, Fety A. Rakotomalala, Rija Ranaivosoa, Jean-Roger Rakotoarijaona, Thomas F. Allnutt, Frédéric Achard
The island of Madagascar has a unique biodiversity, mainly located in the tropical forests of the island. This biodiversity is highly threatened by anthropogenic deforestation. Existing historical forest maps at national level are scattered and have substantial gaps which prevent an exhaustive assessment of long-term deforestation trends in Madagascar. In this study, we combined historical national forest cover maps (covering the period 1953–2000) with a recent global annual tree cover loss dataset (2001–2014) to look at six decades of deforestation and forest fragmentation in Madagascar (from 1953 to 2014). We produced new forest cover maps at 30 m resolution for the year 1990 and annually from 2000 to 2014 over the full territory of Madagascar. We estimated that Madagascar has lost 44% of its natural forest cover over the period 1953–2014 (including 37% over the period 1973–2014). Natural forests cover 8.9 Mha in 2014 (15% of the national territory) and include 4.4 Mha (50%) of moist forests, 2.6 Mha (29%) of dry forests, 1.7 Mha of spiny forests (19%) and 177 000 ha (2%) of mangroves. Since 2005, the annual deforestation rate has progressively increased in Madagascar to reach 99 000 ha/yr during 2010–2014 (corresponding to a rate of 1.1%/yr). Around half of the forest (46%) is now located at less than 100 m from the forest edge. Our approach could be replicated to other developing countries with tropical forest. Accurate forest cover change maps can be used to assess the effectiveness of past and current conservation programs and implement new strategies for the future. In particular, forest maps and estimates can be used in the REDD+ framework which aims at “Reducing Emissions from Deforestation and forest Degradation” and for optimizing the current protected area network.
Delineating priority areas for marine biodiversity conservation in the Coral Triangle Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 Irawan Asaad, Carolyn J. Lundquist, Mark V. Erdmann, Mark J. Costello
Identifying priority areas for biodiversity conservation requires systematic approaches and integrated ecological and biological information. Here, we applied a range of ecological criteria to assess areas of biodiversity importance in the Coral Triangle region, a priority region for marine biodiversity conservation because of its high species richness and endemicity. We used distribution data of three biogenic habitats to assess the criterion of sensitive habitat, modeled geographic distributions of 10,672 species ranges and occurrence records of 19,251 species to evaluate the criterion of species richness, distributions of 834 species of special conservation concern to examine the criterion of species of conservation concern, distributions of 373 reef fish species to assess the criterion of restricted-range species, and distribution of nesting sites and migratory route of six species of sea turtle to evaluate the criterion of areas of importance for particular life history stages. We identified areas of biodiversity importance by superimposing each of the different criterion. We performed two tiers of multi-criteria analysis: (1) a Coral Triangle regional level analysis to identify “clustered hotspots” (i.e., groups of cells) of biodiversity significance, and (2) a site-based analysis to identify the specific sites (cells) of greatest biodiversity importance. We found that approximately 13% of the Coral Triangle was clustered into hotspots of high biodiversity importance. These areas occurred along the southern part of the Philippines, the north-eastern part of Malaysian Sabah, central to eastern reaches of Indonesia, the eastern part of Papua New Guinea and the Solomon Islands. By comparison, the site-based analysis identified seven sites of highest biodiversity importance in the Coral Triangle include: (1) the northern tip of Sulawesi Island, (2) Ambon Island, (3) Kei Islands, (4) Raja Ampat Archipelago of Indonesian Papua, (5) the Verde Island Passage, (6) the southern part of Negros Island, and (7) Cebu Island. This information is useful to inform participatory decision-making processes in the Coral Triangle region to identify priority areas for conservation and management.
Tests of predictions associated with temporal changes in Australian bird populations Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 David B. Lindenmayer, Peter Lane, Martin Westgate, Ben C. Scheele, Claire Foster, Chloe Sato, Karen Ikin, Mason Crane, Damian Michael, Dan Florance, Philip Barton, Luke S. O'Loughlin, Natasha Robinson
Global biodiversity loss is the cumulative result of local species declines. To combat biodiversity loss, detailed information on the temporal trends of at-risk species at local scales is needed. Here we report the results of a 13-year study of temporal change in bird occupancy in one of the most heavily modified biomes worldwide; the temperate woodlands of south-eastern Australia. We sought to determine if temporal changes in bird species were different between three broad native vegetation types (old-growth woodland, regrowth woodland and restoration plantings) and between species traits (body size, migratory status, rarity, woodland dependency, or diet). We found evidence of decline for over a quarter of all bird species for which we had sufficient data for detailed analysis (30 out of 108 species). In contrast, only 14 species increased significantly. Temporal change of birds was linked to life-history attributes, with patterns often being habitat-dependent. Nectarivores and large-bodied birds declined across all vegetation types, whereas small-bodied species increased, particularly in restoration plantings. Contrasting with patterns documented elsewhere, resident but not migratory species declined, with this trend strongest in restoration plantings. Finally, our analyses showed that, as a group, common birds tended to decline whereas rare birds tended to increase, with effects for both most pronounced in restoration plantings. Our results highlight the benefit of targeted restoration planting for some species, but also demonstrate that many common species that have long-persisted in human-dominated landscapes are experiencing severe declines.
The potential impacts of the songbird trade on mixed-species flocking Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 William Marthy, Damien R. Farine
Mixed-species flocking is an important avian social system that supports a large number of species. Current reviews of threats to mixed flocks have only examined two types of anthropogenic pressures: different land use intensity and fragmentation. We highlight the bird trade as another major potential threat for many mixed-species flocking species in Southeast Asia. We examine the potential indirect impact of the bird trade by comparing social networks of flocking data collected over two periods nearly 20 years apart (1997 and 2016) from the same site in Sumatra, Indonesia. We find that the structure of the two networks was significantly correlated. However, of the 90 species observed, 49 had previously been identified as part of the bird trade. These species experienced a significantly greater decrease in network centrality over time compared to the non-traded species, resulting in a loss of structure in the mixed-species flocking network. Simulating further disturbances suggests that flocks may not be resilient to the complete loss of two or more traded species. Our results suggest that trapping is likely to be contributing to the degradation of flocks, and ultimately could lead to the widespread declines in those other species that also rely on mixed-species flocking.
Evaluating scenarios of landscape change for Sunda clouded leopard connectivity in a human dominated landscape Biol. Conserv. (IF 4.022) Pub Date : 2018-04-19 Andrew J. Hearn, Samuel A. Cushman, Benoit Goossens, Ewan Macdonald, Joanna Ross, Luke T.B. Hunter, Nicola K. Abram, David W. Macdonald
The forests of Borneo support some of the highest biodiversity in the world, yet have experienced among the world's highest rates of deforestation. Such rapid forest loss and associated fragmentation reduces the availability of suitable habitat for wildlife and creates dispersion barriers. Understanding the prevalence and impacts of this anthropogenic disturbance, and developing ways in which to mitigate such changes, is thus critical to the conservation of Borneo's wildlife. Here, we applied a path selection function with conditional logistic regression and used it to develop a resistance surface for a population of Sunda clouded leopards (Neofelis diardi) residing within a fragmented and human dominated landscape in Malaysian Borneo. We used cumulative resistant kernel and factorial least-cost path analysis to predict how connectivity may change in response to four future scenarios involving conversion of remaining unproductive forest to palm oil plantations, conversion of unproductive palm oil back to forest, and restoration of a riparian buffer zone along the river, and combination of the two forest restoration scenarios. We showed that Sunda clouded leopard movement is facilitated by forest canopy cover and resisted by non-forest vegetation, particularly recently cleared/planted and underproductive (flooded) plantation areas with low canopy closure. By combining resistant kernel and factorial least-cost path modelling we mapped core areas and the main linkages among them, and identified several key pinch points that may limit regional connectivity of the population. We predict that Sunda clouded leopard connectivity in the region can be greatly enhanced through the protection of privately owned forest patches and the reforestation of underproductive oil palm plantation areas, and creation of a forested buffer zone along the river. Conversely, we show that if the region's unprotected forests were to be converted to plantations then connectivity across the Kinabatangan floodplain would be significantly reduced.
Simultaneous detection of invasive signal crayfish, endangered white-clawed crayfish and the crayfish plague pathogen using environmental DNA Biol. Conserv. (IF 4.022) Pub Date : 2018-04-21 Chloe Victoria Robinson, Tamsyn M. Uren Webster, Joanne Cable, Joanna James, Sofia Consuegra
Aquatic invasive species (AIS) are important vectors for the introduction of novel pathogens which can, in turn, become drivers of rapid ecological and evolutionary change, compromising the persistence of native species. Conservation strategies rely on accurate information regarding presence and distribution of AIS and their associated pathogens to prevent or mitigate negative impacts, such as predation, displacement or competition with native species for food, space or breeding sites. Environmental DNA is increasingly used as a conservation tool for early detection and monitoring of AIS. We used a novel eDNA high-resolution melt curve (HRM) approach to simultaneously detect the UK endangered native crayfish (Austropotamobius pallipes), the highly invasive signal crayfish (Pacifastacus leniusculus) and their dominant pathogen, Aphanomyces astaci (causative agent of crayfish plague). We validated the approach using laboratory and field samples in areas with known presence or absence of both crayfish species as well as the pathogen, prior to the monitoring of areas where their presence was unknown. We identified the presence of infected signal crayfish further upstream than previously detected in an area where previous intensive eradication attempts had taken place, and the coexistence of both species in plague free catchments. We also detected the endangered native crayfish in an area where trapping had failed. With this method, we could estimate the distribution of native and invasive crayfish and their infection status in a rapid, cost effective and highly sensitive way, providing essential information for the development of conservation strategies in catchments with populations of endangered native crayfish.
Fission-fusion social structure of a reintroduced ungulate: Implications for conservation Biol. Conserv. (IF 4.022) Pub Date : 2018-04-22 Sharon Renan, Edith Speyer, Tamar Ben-Nun, Alon Ziv, Gili Greenbaum, Alan R. Templeton, Shirli Bar-David, Amos Bouskila
In a reintroduced population, the social behavior of the species can strongly affect the long-term viability of the population through its effects on movement, information flow, disease spread and the population's genetic variability. Therefore, information on the social behavior of a reintroduced population can contribute to conservation practices; however, its importance is often underestimated. The initial phase of the Asiatic wild ass's (Equus hemionus) reintroduction in Israel has been considered a success, and the population is currently estimated at more than 250 individuals. However, the current social structure of the population remained unknown. We aimed to study this important population trait and to provide helpful information for efficient conservation and management protocols. The study was based on direct observations that were conducted over four consecutive years, and on the analyses of groups' composition and female groups' stability. Female groups accompanied by males constituted only 5% of the total 659 observations, males were observed to be mainly solitary or in groups of various sizes, and females were organized in non-stable groups, indicating that the reintroduced population exhibits a fission-fusion social structure. Identifying the social structure for the species in the expanding Negev population of the Asiatic wild ass can assist in implementing future reintroductions and can contribute to effective management decisions aimed at protecting the species.
Defining conservation units with enhanced molecular tools to reveal fine scale structuring among Mediterranean green turtle rookeries Biol. Conserv. (IF 4.022) Pub Date : 2018-04-21 P.J. Bradshaw, A.C. Broderick, C. Carreras, W. Fuller, R.T.E. Snape, L.I. Wright, B.J. Godley
Understanding the connectivity among populations is a key research priority for species of conservation concern. Genetic tools are widely used for this purpose, but the results can be limited by the resolution of the genetic markers in relation to the species and geographic scale. Here, we investigated natal philopatry in green turtles (Chelonia mydas) from four rookeries within close geographic proximity (~200 km) on the Mediterranean island of Cyprus. We genotyped hypervariable mtSTRs, a mtDNA control region sequence (CR) and 13 microsatellite loci to genetically characterise 479 green turtles using markers with different modes of inheritance. We demonstrated matrilineal stock structure for the first time among Mediterranean green turtle rookeries. This result contradicts previous regional assessments and supports a growing body of evidence that green turtles exhibit a more precise level of natal site fidelity than has commonly been recognised. The microsatellites detected weak male philopatry with significant stock structure among three of the six pairwise comparisons. The absence of Atlantic CR haplotypes and mtSTRs amongst these robust sample sizes reaffirms the reproductive isolation of Mediterranean green turtles and supports their status as a subpopulation. A power analysis effectively demonstrated that the mtDNA genetic markers previously employed to evaluate regional stock identity were confounded by an insufficient resolution considering the recent colonisation of this region. These findings improve the regional understanding of stock connectivity and illustrate the importance of using suitable genetic markers to define appropriate units for management and conservation.
When predators become prey: Community-based monitoring of caiman and dolphin hunting for the catfish fishery and the broader implications on Amazonian human-natural systems Biol. Conserv. (IF 4.022) Pub Date : 2018-04-13 Natalia C. Pimenta, Adrian A. Barnett, Robinson Botero-Arias, Miriam Marmontel
Wildlife hunting for commercial products has been responsible for decline of many large vertebrates around the globe. An Amazonian example of this worldwide trend is the use of caiman and dolphins as bait for the piracatinga catfish fishery. While it is a controversial issue in Amazonia conservation, there is no data on key biological aspects, such as age and sex, of those animals illegally hunted for bait. This lack of data complicates understanding of the true impact of bait-hunting on the targeted species. In this study, we present results of one year of participatory monitoring of bait-hunting in 12 communities in the Mamirauá Sustainable Development Reserve (MSDR), Brazilian Amazonia, during which participants recorded aspects of hunting activity and biometric data of animals used as piracatinga bait. The piracatinga fishery at MSDR has distinct spatial and seasonal patterns, being concentrated close to distribution centers and intensifying during the dry season. Adult male black caiman is the main bait used by fishermen, but viscera of commercial fish provide a potential alternative bait source for the piracatinga fishery. All recorded bait hunting was for caiman, none for dolphins. Despite the predominant use of caiman as bait, MSDR caiman populations remain the largest within the species' distribution. We suggest that informal management of caiman conducted by MSDR residents has guaranteed regional sustainability of the piracatinga fishery. In a broader context, the current study highlights the potential for participatory research with local populations in formulating well-informed decisions for the conservation of natural resources and economic alternatives focused on the conservation of human-natural systems.
A predictive model based on multiple coastal anthropogenic pressures explains the degradation status of a marine ecosystem: Implications for management and conservation Biol. Conserv. (IF 4.022) Pub Date : 2018-04-11 Florian Holon, Guilhem Marre, Valeriano Parravicini, Nicolas Mouquet, Thomas Bockel, Pierre Descamp, Anne-Sophie Tribot, Pierre Boissery, Julie Deter
During the last fifty years, there has been a dramatic increase in the development of anthropogenic activities, and this is particularly threatening to marine coastal ecosystems. The management of these multiple and simultaneous anthropogenic pressures requires reliable and precise data on their distribution, as well as information (data, modelling) on their potential effects on sensitive ecosystems. Focusing on Posidonia oceanica beds, a threatened habitat-forming seagrass species endemic to the Mediterranean, we developed a statistical approach to study the complex relationship between human multiple activities and ecosystem status. We used Random Forest modelling to explain the degradation status of P. oceanica (defined herein as the shift from seagrass bed to dead matte) as a function of depth and 10 anthropogenic pressures along the French Mediterranean coast (1700 km of coastline including Corsica). Using a 50 × 50 m grid cells dataset, we obtained a particularly accurate model explaining 71.3% of the variance, with a Pearson correlation of 0.84 between predicted and observed values. Human-made coastline, depth, coastal population, urbanization, and agriculture were the best global predictors of P. oceanica's degradation status. Aquaculture was the least important predictor, although its local individual influence was among the highest. Non-linear relationship between predictors and seagrass beds status was detected with tipping points (i.e. thresholds) for all variables except agriculture and industrial effluents. Using these tipping points, we built a map representing the coastal seagrass beds classified into four categories according to an increasing pressure gradient and its risk of phase shift. Our approach provides important information that can be used to help managers preserve this essential and endangered ecosystem.
Tree plantations displacing native forests: The nature and drivers of apparent forest recovery on former croplands in Southwestern China from 2000 to 2015 Biol. Conserv. (IF 4.022) Pub Date : 2018-04-10 Fangyuan Hua, Lin Wang, Brendan Fisher, Xinlei Zheng, Xiaoyang Wang, Douglas W. Yu, Ya Tang, Jianguo Zhu, David S. Wilcove
China is credited with undertaking some of the world's most ambitious policies to protect and restore forests, which could serve as a role model for other countries. However, the actual environmental consequences of these policies are poorly known. Here, we combine remote-sensing analysis with household interviews to assess the nature and drivers of land-cover change in southwestern China between 2000–2015, after China's major forest protection and reforestation policies came into effect. We found that while the region's gross tree cover grew by 32%, this increase was entirely due to the conversion of croplands to tree plantations, particularly monocultures. Native forests, in turn, suffered a net loss of 6.6%. Thus, instead of truly recovering forested landscapes and generating concomitant environmental benefits, the region's apparent forest recovery has effectively displaced native forests, including those that could have naturally regenerated on land freed up from agriculture. The pursuit of profit from agricultural or forestry production along with governmental encouragement and mobilization for certain land uses – including tree planting – were the dominant drivers of the observed land-cover change. An additional driver was the desire of many households to conform with the land-use decisions of their neighbors. We also found that households' lack of labor or financial resources, rather than any policy safeguards, was the primary constraint on further conversion of native forests. We conclude that to achieve genuine forest recovery along with the resulting environmental benefits, China's policies must more strongly protect existing native forests and facilitate native forest restoration. Natural regeneration, which thus far has been grossly neglected in China's forest policies, should be recognized as a legitimate means of forest restoration. In addition, social factors operating at the household level, notably the pursuit of profit and conformation to social norms, should be harnessed to promote better land-cover, biodiversity, and environmental outcomes. More generally, for China and other countries to succeed in recovering forests, policies must clearly distinguish between native forests and tree plantations.
Quantifying the conservation value of Sacred Natural Sites Biol. Conserv. (IF 4.022) Pub Date : 2018-04-09 D.N. Avtzis, K. Stara, V. Sgardeli, A. Betsis, S. Diamandis, J.R. Healey, E. Kapsalis, V. Kati, G. Korakis, V. Marini Govigli, N. Monokrousos, L. Muggia, V. Nitsiakos, E. Papadatou, H. Papaioannou, A. Rohrer, R. Τsiakiris, K.S. Van Houtan, D. Vokou, J.L.G. Wong, J.M. Halley
Many have asserted that Sacred Natural Sites (SNS) play an important role in nature protection but few have assessed their conservation effectiveness for different taxa. We studied sacred groves in Epirus, NW Greece, where a large number of such SNS have been identified. Based on historical, ethnographic and ecological criteria, we selected eight of these groves and matching control sites and in them we studied fungi, lichens, herbaceous plants, woody plants, nematodes, insects, bats and passerine birds. Our results reveal that the contribution of SNS to species conservation is nuanced by taxon, vegetation type and management history. We found that the sacred groves have a small conservation advantage over the corresponding control sites. More specifically, there are more distinct sets of organisms amongst sacred groves than amongst control sites, and overall biodiversity, diversity per taxonomic group, and numbers of species from the European SCI list (Species of Community Interest) are all marginally higher in them. Conservationists regard the often small size of SNS as a factor limiting their conservation value. The sizes of SNS around the globe vary greatly, from a few square meters to millions of hectares. Given that those surveyed by us (ranging from 5 to 116 ha) are at the lower end of this spectrum, the small conservation advantage that we testified becomes important. Our results provide clear evidence that even small-size SNS have considerable conservation relevance; they would contribute most to species conservation if incorporated in networks.
Diversity and community structure of rapids-dwelling fishes of the Xingu River: Implications for conservation amid large-scale hydroelectric development Biol. Conserv. (IF 4.022) Pub Date : 2018-04-09 Daniel B. Fitzgerald, Mark H. Sabaj Perez, Leandro M. Sousa, Alany P. Gonçalves, Lucia Rapp Py-Daniel, Nathan K. Lujan, Jansen Zuanon, Kirk O. Winemiller, John G. Lundberg
A recent boom in hydroelectric development in the world's most diverse tropical river basins is currently threatening aquatic biodiversity on an unprecedented scale. Among the most controversial of these projects is the Belo Monte Hydroelectric Complex (BMHC) on the Xingu River, the Amazon's largest clear-water tributary. The design of the BMHC creates three distinctly altered segments: a flooded section upstream of the main dam, a middle section between the dam and the main powerhouse that will be dewatered, and a downstream section subject to flow alteration from powerhouse discharge. This region of the Xingu is notable for an extensive series of rapids known as the Volta Grande that hosts exceptional levels of endemic aquatic biodiversity; yet, patterns of temporal and spatial variation in community composition within this highly threatened habitat are not well documented. We surveyed fish assemblages within rapids in the three segments impacted by the BMHC prior to hydrologic alteration, and tested for differences in assemblage structure between segments and seasons. Fish species richness varied only slightly between segments, but there were significant differences in assemblage structure between segments and seasons. Most of the species thought to be highly dependent on rapids habitat, including several species listed as threatened in Brazil, were either restricted to or much more abundant within the upstream and middle segments. Our analysis identified the middle section of the Volta Grande as critically important for the conservation of this diverse, endemic fish fauna. Additional research is urgently needed to determine dam operations that may optimize energy production with an environmental flow regime that conserves the river's unique habitat and biodiversity.
‘Genetic resources’, an analysis of a multifaceted concept Biol. Conserv. (IF 4.022) Pub Date : 2018-04-06 Anna Deplazes-Zemp
‘Genetic resources’ is a key concept of the Convention on Biological Diversity (CBD) and the Nagoya Protocol (NP). However, the term was coined to describe value in biodiversity and create an incentive for its protection and is thus of practical relevance for biological conservation beyond the legal context. The scope of this concept is also of interest to researchers, who may be unsure for which types of analysis they are legally and ethically expected to enter access and benefit sharing (ABS) negotiations. This article presents a biologically informed analysis, which leads to an understanding of ‘genetic resources’ that considers various associations and implications of this notion, such as its relation to biodiversity and the role that intellectual property rights (IPR) play in the discourse. The aim is to provide a coherent, consistent and comprehensive understanding of the concept that can integrate and explain these aspects and consider both classical and novel ways of using genetic resources. Based on the biological function of genetic resources and an analysis of how they are currently used and valued, this article argues that genetic resources are a particular type of natural resource that is informational rather than tangible. This interpretation clearly identifies utilising digital genomic sequences as a form of using genetic resources. However, the article also discusses regulatory exceptions for certain utilisations of genetic resources and it mentions the possibility of treating digital sequences as such an exception.
Public attitudes towards “pest” management: Perceptions on squirrel management strategies in the UK Biol. Conserv. (IF 4.022) Pub Date : 2018-04-06 Mike Dunn, Mariella Marzano, Jack Forster, Robin M.A. Gill
The impacts of non-native, invasive grey squirrels (Sciurus carolinensis) on broadleaf woodlands and red squirrel population (Sciurus vulgaris) are well recognised among wildlife professionals, yet efforts to control the species across its expanding range require substantial time and resources. Through collaboration, wildlife professionals and communities can more effectively implement the population monitoring and control programmes necessary to conserve native species under threat. However, for such collaboration to be successful, wildlife professionals must first understand public attitudes towards grey squirrels, and the control methods available. Through a national level survey (n = 3758) we examine the UK public's attitudes to red and grey squirrels, and the acceptability of seven control methods. Results show that much of the public have little knowledge of the grey squirrel's negative impacts. In fact, contrary to the notion of a pest species, the presence of grey squirrels is often desirable. Furthermore, those control methods recommended by wildlife professionals are regarded by the public as some of the least acceptable. Those most accepting of controls include males, older generations, those most knowledgeable about squirrels and people who are aware of squirrel management being practiced in their local area. To foster more fruitful collaboration, wildlife professionals should raise awareness of why particular control methods are preferred, highlight the damage grey squirrels cause to other valued species, and offer local communities a variety of roles which contribute to the wider goal of native species conservation.
Major global changes interact to cause male-biased sex ratios in a reptile with temperature-dependent sex determination Biol. Conserv. (IF 4.022) Pub Date : 2018-04-06 M.M. Thompson, B.H. Coe, R.M. Andrews, D.F. Stauffer, D.A. Cristol, D.A. Crossley II, W.A. Hopkins
Habitat loss and pollution are two of the greatest global threats to biodiversity. Due to their widespread prevalence, these threats often co-occur, yet their interactive effects on organisms remain poorly understood. Some reptiles are vulnerable to these threats because they have specific microclimate requirements for embryonic development and because pollutants are maternally transferred to their eggs; both incubation temperature and pollutants affect reptile sex determination. In aquatic turtles, females often select nest sites in recently planted agricultural fields but the impact of nesting in polluted agricultural habitats is not understood. We examined the influences of crop agriculture and mercury pollution on nest microclimate and offspring sex ratios of Chelydra serpentina. We hypothesized that crop growth in agricultural fields would shade and cool turtle nests, decrease moisture levels, increase male offspring production, and interact with maternally-derived mercury to impact sex determination. As predicted, nests shaded by crops had lower average temperatures (−2.5 °C) and moisture levels (−107 kPa) than control nests. In field and laboratory experiments, agricultural thermal regimens increased the proportion of male offspring in clutches and this effect was intensified in the presence of mercury. Global temperatures are expected to rise within the 21st century and to have a feminizing effect on reptiles with temperature-dependent sex determination. That prediction should be refined to incorporate how the cooling effect of some local habitat conditions (e.g., agricultural fields), and interactions between anthropogenic land-use and common pollutants, will interact with climate change to influence sex ratios of reptiles with temperature-dependent sex determination.
Slow and steady wins the race? Future climate and land use change leaves the imperiled Blanding's turtle (Emydoidea blandingii) behind Biol. Conserv. (IF 4.022) Pub Date : Christopher M. Hamilton, Brooke L. Bateman, Jessica M. Gorzo, Brendan Reid, Wayne E. Thogmartin, M. Zachariah Peery, Patricia J. Heglund, Volker C. Radeloff, Anna M. Pidgeon
Climate change is accompanied by shifts in species distributions, as portions of current ranges become less suitable. Maintaining or improving landscape connectivity to facilitate species movements is a primary approach to mitigate the effects of climate change on biodiversity. However, it is not clear how ongoing changes in land use and climate may affect the existing connectivity of landscapes. We evaluated shifts in habitat suitability and connectivity for the imperiled Blanding's turtle (Emydoidea blandingii) in Wisconsin using species distribution modeling in combination with different future scenarios of both land use change and climate change for the 2050s. We found that climate change had significant effects on both habitat suitability and connectivity, however, there was little difference in the magnitude of effects among different economic scenarios. Under both our low- and high-CO2 emissions scenarios, suitable habitat for the Blanding's turtle shifted northward. In the high-emissions scenario, almost no suitable habitat remained for Blanding's turtle in Wisconsin by the 2050s and there was up to a 100,000-fold increase in landscape resistance to turtle movement, suggesting the landscape essentially becomes impassable. Habitat loss and landscape resistance were exponentially greater in southern versus northern Wisconsin, indicating a strong trailing edge effect. Thus, populations at the southern edge of the range are likely to “fall behind” shifts in suitable habitat faster than northern populations. Given its limited dispersal capability, loss of suitable habitat may occur at a rate far faster than the Blanding's turtle can adjust to changing conditions via shifts in range.
Is disease a major causal factor in declines? An Evidence Framework and case study on koala chlamydiosis Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 Laura F. Grogan, Alison J. Peel, Douglas Kerlin, William Ellis, Darryl Jones, Jean-Marc Hero, Hamish McCallum
Determining the role of an infectious agent in contributing to wildlife population declines is a pervasive problem in the field of conservation biology. We expand on a recently proposed broad investigative approach for disease, with a systematic framework outlining the specific types of individual- and population-scale empirical evidence required to demonstrate whether a pathogen is a component cause of declines in wild animal populations. Using koala (Phascolarctos cinereus) population declines and their putative association with the bacterial disease chlamydiosis (Family Chlamydiaceae) as a case study, we review the relevant published literature and synthesize a logical conceptual argument based on our suggested framework. Available empirical evidence supports a role for chlamydiosis contributing to host mortality and sterility, and cannot rule out a role of chlamydiosis as a component cause of koala population declines. However, the relative importance of chlamydiosis (among other threatening processes) as a driver of changes in koala demography and autecology may differ depending on the particular population or system examined, and this has yet to be elucidated over the koala's distributional range. Our approach allows us to highlight current research gaps in order to assist with future policy planning and conservation strategy. We recommend that a similar approach will assist in the evaluation of the role of disease in population declines in other ecological systems.
The evidence for the bushmeat crisis in African savannas: A systematic quantitative literature review Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 Julia van Velden, Kerrie Wilson, Duan Biggs
Bushmeat hunting, trade and consumption is a growing biodiversity and food security concern. Much of the collated research is currently limited to forested regions however, despite indications of the increasing threat in savannas. Savanna regions are biodiverse and often have high-value wildlife tourism industries, but also have rapidly-growing rural populations, often highly dependent on natural resources. In this systematic quantitative literature review we seek to understand the state of knowledge about bushmeat in savanna regions in Africa. We aim to identify gaps in the literature, both spatially and topically, understand what methodologies are used, what common recommendations are made and what interventions have been quantified. We identified 144 relevant studies from the literature. Although studies have increased over time and diversified thematically, there were strong biases. Most studies were conducted in Tanzania, with gaps in research in southern Africa and the Sahelian region. Additionally, only 25% of papers investigated interventions used to reduce bushmeat hunting, with traditional enforcement being the most common intervention studied (53% of intervention studies, 13% of papers). Other frequently recommended interventions such as alternative incomes received little attention (14% of intervention studies, 3.5% of papers). Further, although many studies cite common drivers of bushmeat hunting such as income or livestock, the evidence for these drivers was lacking and contradictory. We reveal that although bushmeat in savanna regions is gaining recognition, many gaps in knowledge remain. This is the first study to systematically quantify the research about bushmeat in African savannas and aims to inform future research.
Using landscape fragmentation thresholds to determine ecological process targets in systematic conservation plans Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 Philip G. Desmet
Systematic conservation planning requires that quantitative targets be set for both biodiversity pattern and processes. While the challenge of setting quantitative representation targets has been well addressed in the literature, guidelines for conceptualising and setting process targets are lacking. Process targets can be defined as the minimum amount of natural habitat that must remain to ensure the long-term survival of the majority of species. While a representation target may represent the majority of species in a landscape, this target often falls far short of conserving processes necessary for the persistence of these species. This paper explores the potential for landscape ecology research to provide useful insights into developing process targets by relating critical thresholds in habitat amount to the probability of population persistence. It is proposed that these thresholds provide a basis for developing generic top-down ecological process targets in conservation planning. The percolation threshold, theoretically defined at 59%, is increasingly used to inform research into ecological state-shifts and ecosystem resilience. This threshold may provide a basis for developing top-down process targets in instances where comprehensive bottom-up spatial data on individual ecological processes is unavailable. In the context of ongoing global habitat loss, this approach provides a pragmatic, but also potentially biologically meaningful, way of incorporating defensible and quantitative ecological process targets or biodiversity persistence goals into conservation plans.
Global patterns in conservation capacity development Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 Lindsey Elliott, Melanie Ryan, Carina Wyborn
Evaluating the effect of forest loss and agricultural expansion on Sumatran tigers from scat surveys Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 Olutolani Smith, Jinliang Wang, Chris Carbone
Sumatran tigers (Panthera tigris sumatrae) are a critically endangered carnivore restricted to the island of Sumatra, and like many other large mammals on the Indonesian archipelago, they are threatened by high levels of poaching and widespread habitat degradation. Here, we conduct the first range-wide assessment of Sumatran tiger genetics using scat surveys and show that the wild population retains levels of genetic heterozygosity comparable to mainland tigers. However, the population also exhibits signs of subdivision due to the unprecedented rates of deforestation and land conversion in the last 30–40 years. The fact that this subspecies retains such levels of heterozygosity despite high rates of habitat loss and increasing isolation suggests a form of genetic extinction debt with an elevated risk of extinction if no action is taken within the next 30–100 years (see Kenney et al., 2014). However, the inherent time delay in extinction debt provides opportunities for conservation if habitat quality can be improved and connections between existing population fragments can be made. Our study highlights the importance of genetic studies for providing baseline information to improve the population management of highly threatened carnivore species. Mitigating further habitat degradation and expansion of oil palm and other cash crops in this region would improve the viability not only of Sumatran tiger populations, but of other threatened large mammal species as well.
Conservation conundrums and the challenges of managing unexplained declines of multiple species Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 David B. Lindenmayer, Jeff Wood, Christopher MacGregor, Claire Foster, Ben Scheele, Ayesha Tulloch, Philip Barton, Sam Banks, Natasha Robinson, Nick Dexter, Luke S. O'Loughlin, Sarah Legge
The conventional approach to conserving threatened biota is to identify drivers of decline, instigate actions to mitigate threatening processes, and monitor interventions to test their effectiveness and ensure target species recover. In Australia, predation by introduced predators is a threatening process for many native mammals. Here we report the results of a 15 year monitoring study in an iconic Australian reserve, Booderee National Park, where exotic Red Fox (Vulpes vulpes) populations have been controlled through an intensive poison baiting program since 2003. Unexpectedly, we documented the collapse of native mammal fauna during this period, including fully arboreal species that should be largely unaffected by fox predation – such as the nationally Vulnerable Greater Glider (Petauroides volans) and Common Ringtail Possum (Pseudocheirus peregrinus). We used path analysis to explore potential causes of these unexpected declines. We found no compelling evidence to support hypotheses that competition with increasing native species, native predator release, or increases in native herbivores underpinned mammal declines. Beyond the path analysis, data from other studies completed both inside Booderee National Park and outside (where intensive fox baiting does not occur yet depleted fauna species remain), allowed us to rule out several drivers of change. The temporal declines we documented for arboreal marsupials were not anticipated nor explained by any clear mechanism. We propose the use of experimentally-guided reintroductions and translocations to: (1) restore empty niches such as the currently vacant apex mammal predator niche, (2) reconstruct the now depleted arboreal marsupial guild, and (3) further test key hypotheses associated with mammal decline. We also suggest that given the potential for perverse outcomes following large-scale management interventions (even those where there is high confidence of success), wildlife managers should consider maintaining reference areas (where there is no management intervention). Finally, as the declines we documented were unexpected and rapid, there is a clear need to develop more sensitive early warning signals to alert conservation managers to impending problems, allowing them to alter management regimes before major declines occur.
Missing native oyster (Ostrea edulis L.) beds in a European Marine Protected Area: Should there be widespread restorative management? Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 Jose M. Fariñas-Franco, Bryony Pearce, James M. Mair, Dan B. Harries, Rebecca C. MacPherson, Joanne S. Porter, Paula J. Reimer, William G. Sanderson
Anthropogenic pressures on the marine environment have escalated and shellfish habitats have declined substantially around the world. Recently, Marine Protected Areas (MPAs) have rapidly increased in number, but management baselines rarely account for historical conditions. Marine examples of habitat restoration are therefore unusual. An interdisciplinary review of management baselines was undertaken for the Dornoch Firth protected area (NE Scotland) as well as three adjacent inlets and 50 km of open coastline. The protected area has low levels of industrial development, is sparsely populated, and previously achieved management objectives. Here we systematically searched for historical evidence of native oyster (Ostrea edulis) beds, a habitat now rare and of conservation importance throughout Atlantic Europe. Archaeological records, navigational charts, historical maps, museum collections, land-use records, fisheries records, public online databases and naturalists' records were searched. We conducted intertidal and subtidal surveys and sample oyster shells were radiocarbon dated. The combined interdisciplinary sources showed that O. edulis occurred in the inlets and open coast areas of NE Scotland, and specifically in the protected area: Probably since the end of the last glaciation to the late 1800s when they were likely over-fished. Present environmental conditions are also suitable for oyster restoration. Habitat restoration in protected areas is an emerging global theme. However, European oyster restoration effort is currently confined to remnant populations with a clear history of exploitation or dwindling associated fisheries. An interdisciplinary review of baselines will probably show scope for the restoration of O. edulis, for nature conservation, in many other European MPAs.
Species richness, geographic distribution, pressures, and threats to bats in the Caatinga drylands of Brazil Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 Ulremberg Barbosa Teodoro da Silva, Mariana Delgado-Jaramillo, Ludmilla Moura de Souza Aguiar, Enrico Bernard
Tropical dry forests (TDF) are threatened worldwide, affected by conversion to agriculture, fragmentation, fires, and climate change. Most of the remaining TDF are in South America, including Brazil's Caatinga. Understanding how the biota of TDFs responds to habitat loss and climate change is a scientific challenge, especially to diversified groups, such as bats, whose richness and ecological roles in TDF are usually underestimated. We updated and synthesized occurrence data and generated distribution models for Caatinga bats considering present and future scenarios. At least 96 species, 48 genera, and eight families were recorded, including two endemic species; five additional species may occur in the biome. The highest potential species richness occurs in the east, in the Caatinga/Atlantic Forest ecotone; the lowest in the west, in the Caatinga/Cerrado ecotone. Current and projected deforestation led to a reduction of 65% in areas with very high potential richness, and only 0.4% will remain within current protected areas. In a business as usual scenario (i.e., high and fast habitat loss + low in situ protection + high potential exposure to climate change) the bat fauna of the Caatinga will be negatively impacted. Improving the conservation of roosting and foraging sites, with the expansion and/or creation of protected areas is urgently needed.
Low extinction risk for an important plant resource: Conservation assessments of continental African palms (Arecaceae/Palmae) Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 Ariane Cosiaux, Lauren M. Gardiner, Fred W. Stauffer, Steven P. Bachman, Bonaventure Sonké, William J. Baker, Thomas L.P. Couvreur
Although the palm flora of continental Africa totals just 66 species, they are amongst the most useful plants across the continent, providing many important resources for human populations. Studies have shown that African palms will likely be negatively affected by global change, leading to increased threats to their survival. Here we conduct the first full global conservation assessment for 61 continental African palm species following IUCN Red List Categories and Criteria. Our study revealed that fewer than 10% of the evaluated species were assessed as Threatened. Within the Threatened category, one species was assessed as Critically Endangered, three as Endangered and two as Vulnerable. These results underline an overall low extinction risk for African palms in the immediate future, which is substantially lower than the global estimate of 21% for all plants. These results could be linked to the generally large distribution patterns of African palm species, the broad ecological amplitudes of most species and their good representation inside the African protected areas network. However, a non-negligible number of species (~15%) lack sufficient data to be properly assessed. This highlights the importance of further studies to improve our basic understanding of their distribution and threats. Our study provides a rather optimistic view of this highly important African plant resource yet, some widespread species are becoming locally rare due to over-harvesting for human use. At a local level, palm resources are generally non-sustainably exploited, which, coupled with climate change, could lead to a rapid increase in threat status over time.
Rain, forests and farmers: Evidence of drought induced deforestation in Madagascar and its consequences for biodiversity conservation Biol. Conserv. (IF 4.022) Pub Date : 2018-04-05 Sébastien Desbureaux, Richard Damania
Cropland expansion is the primary driver of deforestation worldwide. Since land and rainfall are two crucial inputs for agricultural production, a lack of rainfall may have severe consequences on yields, which in turn may lead to a change in cultivated areas, with possible impacts on deforestation rates. Our paper explores this issue of drought induced deforestation that has been largely neglected in the literature. By focusing on Madagascar where agriculture is mostly rainfed, we demonstrate that between 2000 and 2013, clearing additional forests was a strategy that farmers employ to cope with the negative impacts of droughts. Using remote sensing data and fixed-effects panel regressions, we find that droughts increased deforestation by 7.6% compared to years of near normal weather. The impact was most severe in dry and semi-arid areas (up to +17%). When droughts occurred across consecutive years, deforestation declined, a result that is consistent with risk averse behavior of farmers. We show that these results are not driven by ecological mechanisms or by accidental fires. We then study the implication of these outcomes for conservation policy and demonstrate that protected areas were partly effective at buffering against upsurges in deforestation induced by droughts. Our results reinforce the notion that when deforestation is an agricultural problem, agricultural solutions must be combined with conservation policies to decrease deforestation.
Food and livelihoods in park-adjacent communities: The case of the Odzala Kokoua National Park Biol. Conserv. (IF 4.022) Pub Date : 2018-04-04 Germain A. Mavah, Stephan M. Funk, Brian Child, Marilyn E. Swisher, Robert Nasi, John E. Fa
Protected areas (PAs) in Central Africa provide unprecedented opportunities to maintain ecosystem integrity and safeguard the unique wildlife of one of the most biodiverse regions in the world. However, conflicts exist between wildlife protection, and the needs of human populations adjacent to PAs. Although the use of wildlife resources within PAs is nominally regulated, wildlife exploitation in the areas surrounding parks benefit human nutrition and livelihoods of adjacent populations. In 2013–2014, we interviewed 28% of all known households in 37 villages surrounding the Odzala Kokoua National Park (OKNP), Republic of Congo. We gathered information on bushmeat consumption, income, material assets, and hunter perception of the state of wildlife. We show that bushmeat species (mostly duikers, small monkeys and porcupine) were consumed in 38–48% of meals, and 20–30% of households earned cash from hunting wildlife in most villages; more than any other single source of revenue, except cocoa. Although it remains unknown whether the park was a reservoir for wildlife for areas around the studied villages, we showed that more bushmeat was consumed closer to OKNP. By contrast, income from bushmeat sales in villages closer to markets was greater, and as a corollary, market access and household wealth were positively correlated. Overall, total household income, income from bushmeat sales, travel time, and distance to the OKNP were good predictors of household wealth. Wildlife, although considered more abundant around villages closest to the park, was perceived as generally declining around all village groups. Our results highlight the possible importance of PAs and adjacent areas as reservoirs of wildlife and in maintaining wild meat resources used by the surrounding human populations.
Bird collisions with power lines: State of the art and priority areas for research Biol. Conserv. (IF 4.022) Pub Date : 2018-03-30 J. Bernardino, K. Bevanger, R. Barrientos, J.F. Dwyer, A.T. Marques, R.C. Martins, J.M. Shaw, J.P. Silva, F. Moreira
Transmission and distribution electricity grids are expanding rapidly worldwide, with significant negative impacts on biodiversity and, in particular, on birds. We performed a systematic review of the literature available on bird collisions with power lines to: (i) assess overall trends in scientific research in recent decades; (ii) review the existing knowledge of species-specific factors (e.g. vision, morphology), site-specific factors (e.g. topography, light and weather conditions, and anthropogenic disturbance), and power line-specific factors (e.g. number of wire levels, wire height and diameter) known to contribute to increased bird collision risk; and (iii) evaluate existing mitigation measures (e.g. power line routing, underground cabling, power line configuration, wire marking), as well as their effectiveness in reducing collision risk. Our literature review showed (i) there is comparatively little scientific evidence available for power line-specific factors, (ii) there is a scarcity of studies in Asia, Africa and South America, and (iii) several recommendations of good practice are still not supported by scientific evidence. Based on knowledge gaps identified through this review, we outline suggestions for future research and possible innovative approaches in three main areas: bird behaviour (e.g. further use of loggers and sensors), impact assessment (e.g. understanding the drivers of mortality hotspots, assess population-level impacts, develop methods for automatic detection of collisions) and mitigation measures (e.g. further need of BACI approaches to compare the effectiveness of different wire marking devices). The complex and region-specific interactions between collision drivers and bird ecology continue to limit our ability to predict impacts and the success of mitigation measures.
Domestic mammals facilitate tick-borne pathogen transmission networks in South African wildlife Biol. Conserv. (IF 4.022) Pub Date : 2018-03-19 Marcela P.A. Espinaze, Eléonore Hellard, Ivan G. Horak, Graeme S. Cumming
As changes in the environment have brought wild and domestic animals into closer proximity, cross-species disease transmission has become a major concern in wildlife conservation. The worldwide impacts of tick-borne diseases require an understanding of pathogen transmission dynamics across different host species. Livestock are often kept near protected areas and frequently share habitat with wild animals. The influence of host community composition on tick-borne pathogen transmission remains poorly understood, making it difficult to determine whether sharing habitats with domestic livestock increases tick-borne disease in wildlife populations. We used network analysis to analyse 35,349 collections of 54 tick species in South Africa, treating hosts as nodes and shared tick species as links. Across all life stages, 93 mammalian species were connected by a total of 3105 links. Sheep, goats, and dogs were particularly important domestic species for network connectivity; and for wild animals, soft-skinned, smaller mammals such as the scrub hare. Although South African ticks exhibit some specialization on wild animals, network analysis showed that opportunistic feeding on domestic hosts can lead to shortened transmission pathways and facilitate pathogen spread between mammal species. Mammal species are highly interconnected through the tick species that they share, and domestic mammals significantly increase the risk of disease transmission. These findings support conservation measures that limit contact between domestic and wild mammals to reduce tick-borne disease transmission. Grazing in protected areas must be evaluated in light of disease risks to both domestic and wild animals, and potentially also to people.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
- Acc. Chem. Res.
- ACS Appl. Mater. Interfaces
- ACS Biomater. Sci. Eng.
- ACS Catal.
- ACS Cent. Sci.
- ACS Chem. Biol.
- ACS Chem. Neurosci.
- ACS Comb. Sci.
- ACS Earth Space Chem.
- ACS Energy Lett.
- ACS Infect. Dis.
- ACS Macro Lett.
- ACS Med. Chem. Lett.
- ACS Nano
- ACS Omega
- ACS Photonics
- ACS Sens.
- ACS Sustainable Chem. Eng.
- ACS Synth. Biol.
- Acta Biomater.
- Acta Crystallogr. A Found. Adv.
- Acta Mater.
- Adv. Colloid Interface Sci.
- Adv. Electron. Mater.
- Adv. Energy Mater.
- Adv. Funct. Mater.
- Adv. Healthcare Mater.
- Adv. Mater.
- Adv. Mater. Interfaces
- Adv. Opt. Mater.
- Adv. Sci.
- Adv. Synth. Catal.
- AlChE J.
- Anal. Bioanal. Chem.
- Anal. Chem.
- Anal. Chim. Acta
- Anal. Methods
- Angew. Chem. Int. Ed.
- Annu. Rev. Anal. Chem.
- Annu. Rev. Biochem.
- Annu. Rev. Environ. Resour.
- Annu. Rev. Food Sci. Technol.
- Annu. Rev. Mater. Res.
- Annu. Rev. Phys. Chem.
- Appl. Catal. A Gen.
- Appl. Catal. B Environ.
- Appl. Clay. Sci.
- Appl. Energy
- Aquat. Toxicol.
- Arab. J. Chem.
- Asian J. Org. Chem.
- Atmos. Environ.
- Carbohydr. Polym.
- Catal. Commun.
- Catal. Rev. Sci. Eng.
- Catal. Sci. Technol.
- Catal. Today
- Cell Chem. Bio.
- Cem. Concr. Res.
- Ceram. Int.
- Chem. Asian J.
- Chem. Bio. Drug Des.
- Chem. Biol. Interact.
- Chem. Commun.
- Chem. Educ. Res. Pract.
- Chem. Eng. J.
- Chem. Eng. Sci.
- Chem. Eur. J.
- Chem. Mater.
- Chem. Phys.
- Chem. Phys. Lett.
- Chem. Phys. Lipids
- Chem. Rev.
- Chem. Sci.
- Chem. Soc. Rev.
- Chin. J. Chem.
- Combust. Flame
- Compos. Part A Appl. Sci. Manuf.
- Compos. Sci. Technol.
- Compr. Rev. Food Sci. Food Saf.
- Comput. Chem. Eng.
- Constr. Build. Mater.
- Coordin. Chem. Rev.
- Corros. Sci.
- Crit. Rev. Food Sci. Nutr.
- Crit. Rev. Solid State Mater. Sci.
- Cryst. Growth Des.
- Curr. Opin. Chem. Eng.
- Curr. Opin. Colloid Interface Sci.
- Curr. Opin. Environ. Sustain
- Curr. Opin. Solid State Mater. Sci.
- Ecotox. Environ. Safe.
- Electrochem. Commun.
- Electrochim. Acta
- Energy Environ. Sci.
- Energy Fuels
- Energy Storage Mater.
- Environ. Impact Assess. Rev.
- Environ. Int.
- Environ. Model. Softw.
- Environ. Pollut.
- Environ. Res.
- Environ. Sci. Policy
- Environ. Sci. Technol.
- Environ. Sci. Technol. Lett.
- Environ. Sci.: Nano
- Environ. Sci.: Processes Impacts
- Environ. Sci.: Water Res. Technol.
- Eur. J. Inorg. Chem.
- Eur. J. Med. Chem.
- Eur. J. Org. Chem.
- Eur. Polym. J.
- J. Acad. Nutr. Diet.
- J. Agric. Food Chem.
- J. Alloys Compd.
- J. Am. Ceram. Soc.
- J. Am. Chem. Soc.
- J. Am. Soc. Mass Spectrom.
- J. Anal. Appl. Pyrol.
- J. Anal. At. Spectrom.
- J. Antibiot.
- J. Catal.
- J. Chem. Educ.
- J. Chem. Eng. Data
- J. Chem. Inf. Model.
- J. Chem. Phys.
- J. Chem. Theory Comput.
- J. Chromatogr. A
- J. Chromatogr. B
- J. Clean. Prod.
- J. CO2 UTIL.
- J. Colloid Interface Sci.
- J. Comput. Chem.
- J. Cryst. Growth
- J. Dairy Sci.
- J. Electroanal. Chem.
- J. Electrochem. Soc.
- J. Environ. Manage.
- J. Eur. Ceram. Soc.
- J. Fluorine Chem.
- J. Food Drug Anal.
- J. Food Eng.
- J. Food Sci.
- J. Funct. Foods
- J. Hazard. Mater.
- J. Heterocycl. Chem.
- J. Hydrol.
- J. Ind. Eng. Chem.
- J. Inorg. Biochem.
- J. Magn. Magn. Mater.
- J. Mater. Chem. A
- J. Mater. Chem. B
- J. Mater. Chem. C
- J. Mater. Process. Tech.
- J. Mech. Behav. Biomed. Mater.
- J. Med. Chem.
- J. Membr. Sci.
- J. Mol. Catal. A Chem.
- J. Mol. Liq.
- J. Nat. Gas Sci. Eng.
- J. Nat. Prod.
- J. Nucl. Mater.
- J. Org. Chem.
- J. Photochem. Photobiol. C Photochem. Rev.
- J. Phys. Chem. A
- J. Phys. Chem. B
- J. Phys. Chem. C
- J. Phys. Chem. Lett.
- J. Polym. Sci. A Polym. Chem.
- J. Porphyr. Phthalocyanines
- J. Power Sources
- J. Solid State Chem.
- J. Taiwan Inst. Chem. E.
- Macromol. Rapid Commun.
- Mass Spectrom. Rev.
- Mater. Chem. Front.
- Mater. Des.
- Mater. Horiz.
- Mater. Lett.
- Mater. Sci. Eng. A
- Mater. Sci. Eng. R Rep.
- Mater. Today
- Meat Sci.
- Med. Chem. Commun.
- Microchem. J.
- Microchim. Acta
- Micropor. Mesopor. Mater.
- Mol. Biosyst.
- Mol. Cancer Ther.
- Mol. Catal.
- Mol. Nutr. Food Res.
- Mol. Pharmaceutics
- Mol. Syst. Des. Eng.
- Nano Energy
- Nano Lett.
- Nano Res.
- Nano Today
- Nano-Micro Lett.
- Nanomed. Nanotech. Biol. Med.
- Nanoscale Horiz.
- Nat. Catal.
- Nat. Chem.
- Nat. Chem. Biol.
- Nat. Commun.
- Nat. Energy
- Nat. Mater.
- Nat. Med.
- Nat. Methods
- Nat. Nanotech.
- Nat. Photon.
- Nat. Prod. Rep.
- Nat. Protoc.
- Nat. Rev. Chem.
- Nat. Rev. Drug. Disc.
- Nat. Rev. Mater.
- Natl. Sci. Rev.
- Neurochem. Int.
- New J. Chem.
- NPG Asia Mater.
- npj 2D Mater. Appl.
- npj Comput. Mater.
- npj Flex. Electron.
- npj Mater. Degrad.
- npj Sci. Food
- Pharmacol. Rev.
- Pharmacol. Therapeut.
- Photochem. Photobiol. Sci.
- Phys. Chem. Chem. Phys.
- Phys. Life Rev.
- PLOS ONE
- Polym. Chem.
- Polym. Degrad. Stabil.
- Polym. J.
- Polym. Rev.
- Powder Technol.
- Proc. Combust. Inst.
- Prog. Cryst. Growth Ch. Mater.
- Prog. Energy Combust. Sci.
- Prog. Mater. Sci.
- Prog. Photovoltaics
- Prog. Polym. Sci.
- Prog. Solid State Chem.