Regina Macedo

Army-ants (particularly swarm-raiding species Eciton burchellii and Labidus praedator) are keystone predators in Neotropical forests. Hundreds of associated species from diverse taxa depend on them for survival, the most conspicuous of which are the ant-following birds. These birds forage on cryptic arthropods and vertebrates as they attempt to escape raiding army-ants. Despite capturing the attention

The slow-paced life history of many Neotropical birds (e.g., high survival and low fecundity) is hypothesized to increase lifetime fitness through investments in self-maintenance over reproduction relative to their temperate counterparts. Molt is a key investment in self-maintenance and is readily shaped by environmental conditions. As such, variation in molt strategies may be a key mechanism underlying

Eastern (Vireo gilvus gilvus) and western (V. g. swainsoni) forms of the Warbling Vireo have essentially allopatric breeding ranges across north-central North America, but come into contact in central Alberta, Canada. In 1986, Jon Barlow presented preliminary morphological and song evidence suggesting that the Warbling Vireo complex might comprise more than one valid species. However, to date, Barlow’s

André Dhondt

John Rotenberry

Jaime Collazo

Thomas Smith

William R. Dawson, pioneering avian ecophysiologist and long-time faculty member and administrator at the University of Michigan, died March 8, 2020, in Ann Arbor, Michigan. He was born August 24, 1927, in Los Angeles, California, the only child of William E. Dawson, an automotive electrician, and Mary H. Ryan, a bookkeeper. His father died when Bill was aged 5. Bill married Virginia (“Ginny”) Louise

AbstractThe Grallaria rufula complex is currently considered to consist of 2 species, G. rufula (Rufous Antpitta) and G. blakei (Chestnut Antpitta). However, it has been suggested that the complex, populations of which occur in humid montane forests from Venezuela to Bolivia, comprises a suite of vocally distinct yet morphologically cryptic species. We sequenced nuclear and mitochondrial DNA for 80

As in the past, most of the 90 Recent Literature reviews were done by Editor Witmer Stone while W. L. McAtee completed 7 and T. S. “Tombstone” Palmer completed 2. The number of papers reviewed nearly equaled the number of books. Reviews included reports, checklists, and pamphlets. Stone was also responsible for completing the lists, short reviews, and synopses that made up the quarterly sections titled

AbstractBirds exhibit remarkable variation in plumage patterns, both within individual feathers and among plumage patches. Differences in the size, shape, and location of pigments and structural colors comprise important visual signals involved in mate choice, social signaling, camouflage, and many other functions. While ornithologists have studied plumage patterns for centuries, recent technological

AbstractHaemosporidian parasites of the genera Plasmodium, Haemoproteus, and Leucocytozoon are among the best studied parasites of Neotropical birds. Here, we describe variation in haemosporidian prevalence (i.e. the proportion of infected individuals in a sampled population) in Neotropical birds. We review correlates of haemosporidian prevalence (including several avian life-history traits, climate

Bird Bonds: Sex, Mate-Choice and Cognition in Australian Native Birds by KaplanGisela. 2019. Pan McMillan Australia, Sydney, Australia. 354 pp., 50 color photographs and numerous black-and-white photographs, figures, and tables. $34.99 (trade paperback). ISBN 978-1-76055-420-0.

AbstractThe prebasic molt is a perilous period for songbirds, characterized by heightened energetic demands and vulnerability to predators. Given these vulnerabilities, songbirds are under selective pressure to locate and use quality habitat during the prebasic molt, potentially resulting in site fidelity between years. In this study, we aimed to determine how differences in breeding and molting activity

AbstractUsing the patterns of fault bars in their primaries, we studied the mode of primary replacement in non-molting Lesser Sandhill Cranes (Antigone c. canadensis) salvaged from hunters in southwestern Saskatchewan. About 80% of their primaries are used for 2 yr and 20% for 3 yr. Primaries are replaced during the breeding season and are lost in synchronous blocks representing about half the primaries

AbstractInsectivorous birds reach their highest diversity in the tropics and represent a striking variety of morphological and behavioral specializations for foraging, yet explanations for these patterns are inadequate because of both our limited understanding of the drivers of ecological diversification within and among clades and of coexistence mechanisms in particular. Here we synthesize recent

AbstractFunctional diversity (FD) approaches have been increasingly used to understand ecosystem functioning in bird communities. These approaches typically rely on the assumption that species are perfectly detected in the field, despite the fact that imperfect detection represents a ubiquitous source of bias in biodiversity studies. This may be notably important in FD studies, because detection may

AbstractSecuring the long-term resilience of the world’s most speciose avifauna, that of the Neotropics, requires spatially and temporally explicit data to inform decisions. We examine gaps in our knowledge of the region’s avifauna through the lens of the biodiversity shortfall concept: the gaps between realized knowledge and complete knowledge. This framework serves as a useful tool to take stock

AbstractThe Grallaria rufula complex is currently considered to consist of 2 species, G. rufula (Rufous Antpitta) and G. blakei (Chestnut Antpitta). However, it has been suggested that the complex, populations of which occur in humid montane forests from Venezuela to Bolivia, comprises a suite of vocally distinct yet morphologically cryptic species. We sequenced nuclear and mitochondrial DNA for 80

Lay Summary• There is equivocal support for direct associations between maternal quality and deposition of protoporphyrin pigmentation (dark spots and blotches) in avian eggshells.• Research on protoporphyrin eggshell pigmentation has primarily focused on a single avian order (Passeriformes).• We examined associations of protoporphyrin-based eggshell pigmentation with female phenotypic and genetic

AbstractFollowing copulation, females of many seabird species spend a prolonged period of time away from the colony, building up reserves for egg formation and incubation. Here, we report that the number of sperm associated with eggs of single-egg clutch seabirds was almost an order of magnitude greater than predicted from the relationship between ovum size and sperm numbers in multi-egg clutch non-seabirds

Jon Edward Ahlquist died on May 7, 2020, at the age of 75. Thirty years ago, Jon was one of the most famous ornithologists in the world, co-recipient of the 1988 Daniel Giraud Elliot Medal from the National Academy of Sciences and winner of the 1983 Edward’s Prize from the Wilson Ornithological Society. He was also an outstanding bird watcher, artist, and photographer. Yet few ornithologists ever met

AbstractBrood parasitism results in substantial costs to hosts, yet not all species eject foreign eggs. Because the costs of mistakenly ejecting one’s own eggs are high, selection may favor ejection behavior only if it is unlikely a host will incorrectly eject her own eggs. Eastern Bluebirds (Sialia sialis) are currently subject to relatively low levels of interspecific brood parasitism but still sometimes

AbstractHybrid zones are powerful natural settings for investigating how birds diversify into distinct species. Here we present the first genomic-scale exploration of the Baltimore (Icterus galbula) and Bullock’s (I. bullockii) oriole hybrid zone, which is notable for its long history of study and for its prominence in debates about avian species concepts and species limits. We used a reduced-representation

AbstractAlthough the migration ecology of birds breeding in the Neotropics is still poorly studied relative to that of their counterparts breeding at north-temperate latitudes, studies conducted over the last 2 decades have revealed that migration in the Neotropics is much more common and diverse than previously thought. These studies have identified dozens of species that migrate latitudinally within

Hybrids with different combinations of traits can be used to identify genomic regions that underlie phenotypic characters important to species identity and recognition. Here, we explore links between genomic and plumage variation in Blue-winged Warbler x Golden-winged Warbler (Vermivora cyanoptera x V. chrysoptera) hybrids, which have traditionally been categorized into 2 discrete types. “Lawrence’s”

This is the 20th supplement since publication of the 7th edition of the Check-list of North American Birds (American Ornithologists’ Union [AOU] 1998). It summarizes decisions made between April 15, 2019 and April 15, 2020 by the American Ornithological Society’s (formerly American Ornithologists’ Union’s) Committee on Classification and Nomenclature—North and Middle America. The Committee has continued

In 1920, there were over 138 General Notes published in The Auk, 75% of which dealt in some way with distribution. Overall, 70% of all reports originated from east of the Mississippi. Fifteen dealt specifically with irruptions, including Bohemian Waxwings (Bombycilla garrulus), Newfoundland Crossbills (Loxia curvirostra), White-winged Crossbills (L. leucoptera), and Evening Grosbeaks (Coccothraustes

Hermit Warblers (Setophaga occidentalis) sing a formulaic, type I song to attract mates, in contrast to a repertoire of more complex, type II songs to defend territories. A single, dominant type I song, or a low diversity of type I songs, often occur within a geographic area. We provide the first comprehensive description of Hermit Warbler type I song variants throughout California, USA. We recorded

The biodiversity of the Neotropics is considerable, but it is likely underestimated owing to gaps in sampling effort and a focus on using morphological features of animals to determine species differences rather than divergence in their mating signals and behavior. Recent multi-trait analyses incorporating morphological, plumage, and vocal data have allowed for more accurate quantification of tropical

Declines in reproductive performance among older age classes have been reported in many bird and mammal species, and are commonly presented as demonstrating reproductive senescence. However, no declines in performance could be demonstrated in studies of several bird species. We measured reproductive performance in Common Terns (Sterna hirundo) of known age (2–28 yr) during a 19-yr period at a site

Individual recognition is a social behavior that occurs in many bird species. A bird’s ability to discriminate among familiar and unfamiliar conspecifics is critical to avoid wasting resources such as time and energy during social interactions. Black-capped Chickadees (Poecile atricapillus) are able to discriminate individual female and male chick-a-dee calls, potentially male and female tseet calls

AbstractThe ~1.97 million egg sets (~5 million eggs) housed in museums have not been used in proportion to their availability. We highlight the wide variety of scientific disciplines that have used egg collections and the geographic locations and sizes of these collections, to increase awareness of the importance of egg collections, improve their visibility to the scientific community, and suggest

AbstractGenetic variation and phylogeographic studies have been crucial for understanding mechanisms of speciation. We analyzed genetic variation and phylogeography to reconstruct the demographic history of the Rivoli’s Hummingbird (Eugenes fulgens) species complex and also evaluated their morphological differentiation. This widely distributed species inhabits the highlands of Mexico and northern Central

AbstractMigratory shorebirds (Charadrii) show a strong dichotomy in their breeding and wintering strategies: Arctic-breeding species typically spend the wintering season in marine habitats, while more southerly breeding species tend to do so in freshwater habitats where pathogens and parasites, particularly vector-borne blood parasites, are generally more abundant. Thus, it has been hypothesized that

Birds in Winter: Surviving the Most Challenging Season by PasquierRoger F.. 2019. Princeton University Press, Princeton, NJ, USA. 304 pp., 85 b/w illustrations + 4 maps. $29.95 (hardcover). ISBN 978-069-117855-4.

Corey Tarwater

Michael Butler

Kathleen Anderson at her beloved Wolf Trap Hill Farm, May 11, 2019 (photograph by Shawn P. Carey).

Contributions to The History of North American Ornithology, Volume IV, by DavisWilliam E. Jr., Editor. 2019. Memoirs of the Nuttall Ornithological Club, Cambridge, MA, USA. 516 pp., 143 figures. $35.00 (hardcover). ISBN 978-1-877973-51-3

Gloger’s rule is a classic ecogeographical principle that, in its simplest version, predicts animals should be darker in warmer and wetter climates. In a rarely tested more complex version, it also predicts animals should be more rufous in warmer and drier climates. The Variable Antshrike (Thamnophilus caerulescens) is a widely distributed South American passerine that presents an impressive amount

Together, puffbirds (Bucconidae) and jacamars (Galbulidae) form the suborder Galbulae, sister group of all other Piciformes. Hitherto, the Galbulae had no ascertained pre-Pleistocene fossil record, and all previous alleged candidates have been refuted, except possibly the Sylphornithidae. Here we describe a wing of a tiny fossil bird from the early Oligocene of the Luberon region (southern France)

The mass of a bird’s egg is a critical attribute of the species’ life history and represents a fundamental component of reproductive effort. Indeed, the tradeoff between the number of eggs in a clutch and clutch mass lies at the heart of understanding how environmental attributes such as nest predation or adult mortality influence reproductive investment. However, egg masses have not been reported

The vertical structure and composition of vegetation can influence the quantity and quality of potential nesting sites for birds. Interspecific competition for high-quality nesting habitat may force some individuals into suboptimal habitat and lead to reduced reproductive success, eventually leading to changes in distribution or abundance. Large climate-mediated shifts in vegetation, including the

Studying the avian egg, its shape, and other aspects of its morphology, has recently undergone a renaissance. Yet most studies rely solely on 2, albeit multicomponent, metrics for the quantification of egg shape: elongation and asymmetry. The difficulty of quantifying an additional trait, the curvature, of an eggshell has yielded many attempts, including several with complex equations or spatial modeling

Relationships of the Neotropical finches in the genera Euphonia and Chlorophonia (Fringillidae: Euphoniinae) have been clarified by recent molecular studies, but species-level relationships within this group have not been thoroughly addressed. In this study, we sampled specimens representing every recognized species of these genera, in addition to 2 outgroup taxa, and used target enrichment to sequence

Fires of Life: Endothermy in Birds and Mammals by LovegroveBarry G.. 2019. Yale University Press, New Haven, CT, USA. 356 pp. ISBN 978-0-300-227161. $40.00 (cloth)

Robert Whitmore with Mangrove Warbler at Baja California Sur, Mexico, 2010.

Contemporary phenotypic trends associated with global change are widely documented, but whether such trends always denote trait optimization under changed conditions remains obscure. Natural selection has shaped the wings of long-distance migratory birds to minimize the costs of transport, and new optimal wing shapes could be promoted by migration patterns altered due to global change. Alternatively

Acoustic signals used in animal communication play a key role in mate attraction, species recognition, and territory defense. Variation in acoustic signals may reflect population structure, lack of gene flow, and phylogenetic relationships. In birds, the study of geographic variation in acoustic signals has been useful for elucidating potential factors involved in phenotypic divergence and for establishing

Jim Bendell weighing a Spruce Grouse with his wife, Yvonne, recording the data. Photo courtesy of Leah I. Bendell.

Kathleen Anderson at her beloved Wolf Trap Hill Farm, May 11, 2019 (photograph by Shawn P. Carey).

Tony Bledsoe at the Pymatuning Laboratory of Ecology (courtesy of Meg Bledsoe).

We studied the phylogeny, biogeography, and diversification of suboscine passerines in the genus Scytalopus (Rhinocryptidae), a widespread, species-rich, and taxonomically challenging group of Neotropical birds. We analyzed nuclear (exons, regions flanking ultraconserved elements) and mitochondrial (ND2) DNA sequence data for a taxonomically and geographically comprehensive sample of specimens collected

Migratory birds are demonstrating changes in phenology linked to climate change. Understanding these changes requires connecting events that occur over the multiple regions occupied during their annual cycle. The Burrowing Owl (Athene cunicularia) is a species of concern in North America, with pronounced declines in regions of the Great Plains. Using a dataset that spanned 10 breeding sites from South

In 1920, the 37th volume of The Auk included 41 major articles. The lead was a memorial for William Brewster (1851–1919). It was followed by tributes to Brewster and Lyman Belding (1829–1917), and announcements of adoptions of memorials for Brewster. In the inaugural issue of the year, editor Witmer Stone placed a notice of a publication delay and a backlog of submissions, requested a Publication Fund

Natal dispersal and local recruitment are affected by factors both intrinsic and extrinsic to juveniles and may affect fitness. Understanding the relationship between dispersal and population density in birds has been hindered by a lack of long-term studies and a focus on resident species has neglected the role of weather operating at large spatial scales. I studied local recruitment and the reproductive

Density dependence is a conceptual cornerstone of avian population biology and, in territorial songbirds, past research has emphasized interactions among food limitation, density, and reproduction. Documenting the importance of density effects is central to understanding how selective forces shape life histories and population dynamics. During the 2008–2011 breeding seasons, we nearly doubled overall