Variation in cognitive abilities is thought to be linked to variation in brain size, which varies across species with either social factors (Social Intelligence Hypothesis) or ecological challenges (Ecological Intelligence Hypothesis). However, the nature of the ecological processes invoked by the Ecological Intelligence Hypothesis, like adaptations to certain habitat characteristics or dietary requirements

Abstract The environment can play an important role in animal communication by affecting signal transmission and detection. Variation in the signalling environment is expected to be especially pronounced in widely distributed species, potentially affecting how their signals are detected. Such environmental variability is presumably relevant for sedentary females of a nocturnal capital breeder, the

Abstract Eusocial bees are likely to be ecologically important competitors for floral resources, although competitive effects can be difficult to quantify in wild pollinator communities. To investigate this, we excluded honeybees (HBE treatment), bumblebees (BBE) or both (HB&BBE) from wild-growing patches of bramble, Rubus fruticosus L. agg., flowers in two eight-day field trials at separate locations

Abstract Mammalian odors are frequently sexually dimorphic, with males often exhibiting a stronger, or otherwise distinct, odor relative to females, which can be especially useful for nocturnal species with reduced use of vision. Some male bats exhibit intense odors to attract females and reproduce, presumably as a consequence of a high concentration of testosterone. This usually coincides with the

Abstract Mothers provide indispensable care for infants in many mammalian species. In some long-lived species, the maternal-offspring bond persists after infancy with mothers continuing to provide resources and social support to their adult progeny. Maternal presence is associated with fitness benefits through adolescence for male chimpanzees despite the fact that mature males dominate females and

Abstract Sexual segregation in foraging occurs in some species and populations of boobies (Sulidae), but it is not a general pattern. Sexual segregation in foraging may occur to avoid competition for food, and this competition may intensify during specific stages of breeding. We examined sexual segregation in foraging in relation to breeding stage in masked boobies Sula dactylatra at Rapa Nui by tracking

Abstract In polygamy, individuals interact in a non-random manner to shape reproductive networks. However, relative importance of behavior versus individual physical traits (e.g., body size) in determining access to partners and reproductive success varies by species and is poorly understood in small-bodied aquatic species for which direct observations are challenging in the wild. Here, we coupled

Abstract Group-living prey rely on social information such as alarm signals and other social cues to avoid predation. By definition, “signals” imply that a message is voluntarily directed at receivers (i.e., the audience), whereas “cues” are released incidentally regardless of the audience composition. Thus, audience effects can be used to differentiate between signals and cues when communication is

Abstract Bats are a diverse and widespread order of mammals. They fulfill critical ecosystem roles but may also act as reservoirs and spreaders for zoonotic agents. Consequently, many recent studies have focused on the potential of bats to spread diseases to other animals and to humans. However, virus transmission networks within bat colonies remain largely unexplored. We studied the detection rate

Abstract Predator odors are natural stressors that induce anti-predator defensive responses, which have developed under evolutionary pressures to maximize the fitness of an individual to avoid dangerous confrontations. In this study, we analyzed the defensive responses of a subterranean rodent species, the plateau zokor (Eospalax baileyi), to predation threat, and examined the trade-offs between defensive

Abstract Signal divergence and sensory preferences may lead to sexual isolation and eventually promote speciation between animal populations. However, few studies have quantified the degree of chemical signal divergence and scent-mediated sexual isolation in lizard populations. Geographic and ecological variations among populations of the whiptail lizard Aspidoscelis lineattissimus suggest that there

Abstract Annual cycle events may be interlinked, influence following annual cycle stages, and may alter performance of individuals. Such links, called carry-over effects, can explain individual variation in timing or reproductive success in migratory species. Identifying the key links affecting fitness may reveal the mechanisms of species population dynamics but the current evidence for the strongest

Abstract Males and females have divergent reproductive interests arising from their unequal investments in offspring. This sexual conflict drives an antagonistic arms race that influences sex-specific reproductive success. Alternative reproductive tactics are expected in long-lived species for which the reproductive strategy that maximizes mating success could differ across body sizes. The mating strategy

Abstract Status signals have evolved for individuals to avoid energetic and physical costs of resource defense. These signals reflect an individual’s competitive ability and therefore influence competitors’ decisions on how to invest in a fight. We hypothesized that the response of receivers to status signals will depend on the social context. During territorial defense, group members may provide support

Abstract Aggression is one of the most frequently studied behavioural traits across a wide range of taxa; however, most studies evaluate aggressive behaviour in a social context, in which aggressive interactions between conspecifics are motivated by resource control (offensive or social aggression). However, in an antipredator context, the primary role of aggression is defence (defensive or antipredator

Abstract Condition-dependent secondary sexual traits and signals are often crucial for mate choice decisions. Nuptial gifts, provided by the male to the female during mating, may represent an indicator of male condition, especially if production of the gift is energetically costly. Additionally, other signalling modalities may well play a role in mate choice in such systems. Females of the nursery

Abstract Sexual selection theory maintains that traits under selection honestly advertise qualities of signaling individuals and that only individuals in the best condition can survive while displaying maximally elaborated secondary sexual ornaments. Recent trends in mate choice studies have favored the consideration of the effects of multiple traits on mating success, including suites of traits transmitted

Abstract Extra-group paternity, in which offspring are sired by a male outside the breeding group, may alter the distribution of reproductive success in a population, thus affecting the opportunity for sexual selection. Both inter- and intraspecific studies have focused largely on mating systems in which females choose their social mates, and less is known about extra-group paternity in polygynous

Abstract Pre-maturation social experiences may affect post-maturation reproductive strategies of females, including mating preferences and investment in offspring. Whether pre-maturation social experiences affect other aspects of females’ reproductive strategies, including the number of accepted males and post-copulatory decisions, is still an open question. To address this question, we performed laboratory

Abstract Many species throughout the animal kingdom construct nests for reproduction. A nest is an extended phenotype—a non-bodily attribute—of the individual building it. In some bird species, including our study population of blue tits (Cyanistes caeruleus), conspicuous feathers or other material are placed on top of the nest. These so-called nest ornaments do not contribute to nest insulation, but

Abstract It is not uncommon for researchers to want to interrogate paired binomial data. For example, researchers may want to compare an organism’s response (positive or negative) to two different stimuli. If they apply both stimuli to a sample of individuals, it would be natural to present the data in a 2 × 2 table. There would be two cells with concordant results (the frequency of individuals which

Abstract Females often have chromatic patterns that differ from those of males. The evolution and function of female coloration is less known than those of males. Female ornaments can result from non-adaptive intersexual genetic correlation, but they may also signal female quality, health state, or potential fecundity. We examined whether the spectral characteristics of the sexually dichromatic coloration

Abstract Geophagy is the consumption of hard objects with no caloric value (e.g. soil, sand, sediment) called gastroliths. This behaviour is widespread in animals, and among reptiles, geophagy has been reported in crocodilians and lizards and occasionally in chelonians. In this study, we calculated geophagy rates in snapping turtle (Chelydra serpentina) and painted turtle (Chrysemys picta) hatchlings

Abstract Metabolic rate is often cited as the fundamental rate which determines the rate of all biological processes by shaping energetic availability for the various physiological, behavioral, and life-history traits that contribute to performance. It has therefore been suggested that metabolic rate drives the widely observed covariance among these different levels of phenotypic traits. However, much

Abstract The drivers of animal settlement are core topics in ecology. Studies from primaeval habitats provide valuable but rare insights into natural settlement behaviour, where species are unconstrained by habitat fragmentation and modification. We examined whether territorial male songbirds (wood warblers Phylloscopus sibilatrix) exhibited clustered distributions when settling in extensive primaeval

Abstract Sexual signals in different animals are expected to be dimorphic when both sexes signal, but cases of monomorphism are known to occur, and we lack a clear understanding about the factors that modulate the level of sexual dimorphism in signals. In this study, we evaluated the hypothesis that the lack of dimorphism in sexual signals might evolve in systems experiencing temporal changing conditions

Abstract The effective detection of both prey and predators is pivotal for the survival of mesopredators. However, the condition of being a mesopredator is strongly context dependent. Here we focus on two aquatic caudate species that have colonised caves: the Pyrenean newt (Calotriton asper) and the olm (Proteus anguinus). The former maintains both surface and subterranean populations, while only cave-adapted

Abstract Collective defense is one of the most ubiquitous behaviors performed by social groups. Because of its importance, complex societies may engage a set of defensive specialists, with physical and/or neurological attributes tuned for defense against specific invaders. These strategies must be balanced, however, with the need to flexibly respond to different threat levels and sources. Insect societies

Abstract Decisions made during natal dispersal highly influence the future fitness of the animal. The selection of future home range affects, for example, food supply and mating success. In order to select between potential sites, dispersing individuals may use different search strategies, and for example, aim to compare quality of different sites by revisiting them. Alternatively, dispersers visit

Abstract Personality traits (e.g. activity, exploration, boldness) are frequently correlated with each other and with various other traits of biological importance. According to the performance, allocation, and independent models of energy management, the relationship between personality traits and resting metabolic rate (RMR) is predicted to be either positive, negative, or nil. As for the relationship

Abstract Birds may use a variety of cues to select a nest site, including external information on habitat structure and nest site characteristics, or they may rely instead on social information obtained directly or indirectly from the actions of conspecifics. We used an experimental manipulation to determine the extent to which a California population of the wood duck (Aix sponsa) used social information

Abstract Sleep is an essential part of animal biology, yet its ecological aspects such as predator avoidance remain understudied, especially in the wild. Sleep behaviour is likely to be subject to selection pressure and evolution, leading to sleep strategies to ensure survival during this vulnerable state. How sleep strategies of animals respond to alteration of macro-habitat has been largely unexplored

Abstract Coexisting plant species often share the same animal mutualists and enemies. The selection preference of an animal on a focal individual is not only directly affected by the focal individual’s intrinsic traits, but also indirectly affected by conspecific or interspecific neighbouring individuals. Many studies often show inconsistent neighbour effects by comparison of the results between the

Abstract Communal marking sites, or latrines, appear to play an important role in intraspecific communication and social dynamics in a wide range of mammal species. The spatial distribution of latrines can provide clues to their function and has been well documented in a number of species. Latrine use may vary considerably through time, however, and a more comprehensive approach to their study that

Abstract Inhibitory control, the inhibition of prepotent actions, is essential for higher-order cognitive processes such as planning, reasoning, and self-regulation. Individuals and species differ in inhibitory control. Identifying what influences inhibitory control ability within and between species is key to understanding how it evolved. We compared performance in the cylinder task across five lizard

Abstract Many animal signals are brightly colored and convey information about species identity as well as information about individual conspecifics. Colorful bird and lizard signals have received much attention, and many studies have related specific spectral properties of these signals to variation in mating success and territory defense. Far less attention has been given to invertebrates even though

Abstract The horizontal size of the exposed depigmented sclera in Caucasians has been previously suggested to be sexually dimorphic, and the significance of this phenomenon remains unclear. Here we build on a previous study and extend it by (i) examining sex differences in other measures of ocular morphology and (ii) exploring the link between eye morphology and biometric markers of facial attractiveness

Abstract The dominance-nutrition hypothesis predicts that nutritional intake and energetic costs in adulthood interact to drive behavioral and physiological differences between females in primitively eusocial insects, and thereby affect reproductive caste. We tested predictions of this hypothesis in independent-founding Mischocyttarus pallidipectus paper wasps. We measured stable isotope tissue composition

Abstract Social flexibility enables individuals to switch between group and solitary living and is suggested to be an adaptation to varying environments. Several previous studies on different species compared two populations and hypothesized that observed differences in the social organization were due to differences in population density but lacked the necessary sample size to test this prediction

Abstract Socioecological environments that promote frequent interaction and social tolerance have favored the evolution of strong and equitable social bonds, which facilitate cooperation and confer fitness benefits. In most species, kinship is the primary predictor of bond strength and quality, but it does not adequately explain partner choice among adult male chimpanzees. Instead, most bonds and cooperative

Abstract Behaviours such as territorial defence represent functionally integrated traits that underlie multiple behavioural variables such as physical and acoustic responses. Characterizing the multivariate structure of such traits is fundamental to understand their evolution. In bird species that form stable pair bonds and are territorial year-round, both sexes are expected to defend their territory;

Abstract Females mate multiply despite numerous costs. It is well established that polyandry can result in sexual conflict, favoring male adaptations that prevent sperm competition often to the disadvantage of the female. Such adaptations are extreme in spiders with one-shot genitalia of which parts break off and act as mating plugs, rendering them dysfunctional. In the spider Argiope bruennichi, mating

Abstract The lunar cycle is known to affect the behaviour of strictly nocturnal species, but for diurnal species that are periodically active during the night, this has been less investigated. Nocturnal bird song is relatively common in diurnal species, yet research on this behaviour accounts for little of the research on avian vocalisations. This is surprising given that diurnal species are adapted

Abstract Aggression is a context-dependent behavior that often represents an adaptive trade-off with other energetically demanding phenotypes. Diseases can impose strong selection pressures on an organism, impacting the expression of aggression if the behavior is physiologically or genetically linked to disease resistance traits. However, aggression is also often a “sickness behavior” modulated directly

Abstract There is ample evidence that phenotypic traits are important mate choice criteria. Yet, we still know little about the importance of behavioural plasticity in attracting mates, although females could gain direct and/or indirect fitness benefits by choosing males that can adjust their behaviour to environmental fluctuations. Plasticity in foraging tactic use, particularly, might be a key determinant

Abstract The empirical study of the role of sperm competition in the evolution of sexual traits has historically been problematic through the inability either to measure sperm competition levels directly in the present or to reconstruct changes in the evolutionary past. Here, we develop and test a procedure based on paternity data that potentially permits both. For our pilot study, we use the rate

Abstract Food availability sets the stage for incubation behaviour of a female bird and thereby indirectly determines the nest temperature, which in turn affects development and metabolism of avian embryos. Changes in development and metabolism in turn are known to influence offspring’s ability to adjust to environmental changes later in life. However, few studies have investigated the role of interspecific

Abstract In social insects, within-colony worker diversity has long been thought to improve colony fitness. Recent studies start to question this assertion in species with moderate diversity. However, demonstrating an absence of effect is difficult as this absence could be due to the measurement of only few life history traits or to artificial conditions. In order to circumvent these limitations, we

Abstract Rapidly changing environments impose novel selection pressures on organisms, and sometimes adaptive phenotypic plasticity allows organisms to survive and reproduce in the face of environmental change. However, plastic responses can also be maladaptive. In this study, we investigate whether male reproductive investment responds plastically to varied experience with traffic noise. We exposed

Abstract The “life-dinner principle” posits that there is greater selection pressure on the species that have more to lose in an interaction. Thus, based on the asymmetry within predator-prey interactions, there is an advantage for prey to learn quickly, especially in response to novel, introduced predators. Here, we test the “learned recognition” hypothesis that posits that naïve prey species’ ability

Abstract The social network structure of a group arises from the patterns of association of its constituent members, which in turn originates from behaviors and preferences of those individuals. Consequently, an individual’s position in their social environment is commonly related to their own attributes. However, most studies that report such relationships are limited to single or very small numbers

Abstract The most common statistical procedure with a sample of circular data is to test the null hypothesis that points are spread uniformly around the circle without a preferred direction. An array of tests for this has been developed. However, these tests were designed for continuously distributed data, whereas often (e.g. due to limited precision of measurement techniques) collected data is aggregated

Abstract Sexual steroids can play an important role as life-history organizers. In males, high circulating testosterone levels induce physiological/behavioral costs and benefits, leading to trade-offs. However, studies simultaneously testing the impact of these levels in both fitness components (survival and fecundity) during lifetime are scarce and limited to wild birds. To determine the mortality

Abstract Geographic variation in acoustic signals has been investigated for five decades to better understand the evolution of communication. When receivers are able to discriminate among signals and to react accordingly, geographic variation can have major impacts on the ability of conspecifics to communicate. Surprisingly, geographic variation in alarm calls and its consequences for the communication

Abstract When resources are limited and defensible, inter-group encounters in animals are often of aggressive nature. Individuals can participate in inter-group encounters to defend mates, infants, and food resources, but also to attract out-group individuals for additional mating opportunities. Since inter-group conflicts have mainly been studied in group-living species, we examined the mate, infant

Abstract Sexual signals are gained and lost over evolutionary time. While signal gain has obvious fitness benefits, signal loss should present significant costs due to decreased mating opportunities. Just as female mating preferences can promote evolutionary gain and elaboration of sexual signals, they may also maintain signal loss. We investigated how two components of female mate choice are involved

Abstract Research aimed at understanding the evolution of costly, seemingly altruistic helping behaviour in cooperative birds has strongly focused on a single aspect of helping—offspring provisioning. However, various other activities are also important for successful breeding, most notably nest defence, and emphasis on a single aspect of helping might hamper a full understanding of the evolutionary

Abstract In the context of mate choice, males may vary continuously in their expression of assessment signals, typically reflecting information about variation in mate quality. Similarly, females may exhibit variation in mate preference, which could be due to differences in how individual females perceive signals. The extent to which perception varies across individuals, however, and whether differences