Comparative bioacoustics of multiple eastern versus western songbird pairs in North America reveals a gradient of song divergence.

Vocalizations are one of the key premating reproductive barriers that could affect species formation. In song-learning birds, vocal traits are sometimes overlooked in species delimitation, as compared to morphological or plumage-based differences. In this study, we assessed geographic variation in songs of eight pairs of oscines on two scales: (1) comparing primary songs of species/subspecies pairs whose breeding grounds are eastern and western counterparts of each other in the continental North America, and (2) for each counterpart, identifying and comparing possible variation among their populations.

Recently Delisted Songbird Harbors Extensive Genomic Evidence of Inbreeding, Potentially Complicating Future Recovery.

The Kirtland's warbler () is a rare migratory passerine species and habitat specialist of the North American Jack Pine Forests. Their near extinction in the 1970s classified them as endangered and protected under the Endangered Species Act of 1973. After decades of intense conservation management, their population size recovered, and they were delisted from federal protection in 2019.

Association between the gut microbiome and carotenoid plumage phenotype in an avian hybrid zone.

Vertebrates host complex microbiomes that impact their physiology. In many taxa, including colourful wood-warblers, gut microbiome similarity decreases with evolutionary distance. This may suggest that as host populations diverge, so do their microbiomes, because of either tight coevolutionary dynamics, or differential environmental influences, or both.

Genomics-informed conservation units reveal spatial variation in climate vulnerability in a migratory bird.

Identifying genetic conservation units (CUs) in threatened species is critical for the preservation of adaptive capacity and evolutionary potential in the face of climate change. However, delineating CUs in highly mobile species remains a challenge due to high rates of gene flow and genetic signatures of isolation by distance. Even when CUs are delineated in highly mobile species, the CUs often lack key biological information about what populations have the most conservation need to guide management decisions.

Whole genome assessment of a declining game bird reveals cryptic genetic structure and insights for population management.

Population genomics applied to game species conservation can help delineate management units, ensure appropriate harvest levels and identify populations needing genetic rescue to safeguard their adaptive potential. The ruffed grouse (Bonasa umbellus) is rapidly declining in much of the eastern USA due to a combination of forest maturation and habitat fragmentation. More recently, mortality from West Nile Virus may have affected connectivity of local populations; however, genetic approaches have never explicitly investigated this issue.

Genomes of the extinct Bachman's warbler show high divergence and no evidence of admixture with other extant Vermivora warblers.

Bachman's warbler (Vermivora bachmanii)-last sighted in 1988-is one of the only North American passerines to recently go extinct. Given extensive ongoing hybridization of its two extant congeners-the blue-winged warbler (V. cyanoptera) and golden-winged warbler (V.

Dispersal-Limited Symbionts Exhibit Unexpectedly Wide Variation in Host Specificity.

A fundamental aspect of symbiotic relationships is host specificity, ranging from extreme specialists associated with only a single host species to generalists associated with many different species. Although symbionts with limited dispersal capabilities are expected to be host specialists, some are able to associate with multiple hosts. Understanding the micro- and macro-evolutionary causes of variations in host specificity is often hindered by sampling biases and the limited power of traditional evolutionary markers.

Gut microbiome composition better reflects host phylogeny than diet diversity in breeding wood-warblers.

Understanding the factors that shape microbiomes can provide insight into the importance of host-symbiont interactions and on co-evolutionary dynamics. Unlike for mammals, previous studies have found little or no support for an influence of host evolutionary history on avian gut microbiome diversity and instead have suggested a greater influence of the environment or diet due to fast gut turnover. Because effects of different factors may be conflated by captivity and sampling design, examining natural variation using large sample sizes is important.

The genomics of adaptation in birds.

Organismal adaptations are the hallmark of natural selection. Studies of adaptations in avian systems have been central to key conceptual and empirical advances in the field of evolutionary biology and, over the past decade, leveraged the proliferation of a diversity of genomic tools. In this synthesis, we first discuss how the different genomic architectures of avian traits are relevant to adaptive phenotypes.

Genetic confirmation of a hybrid between two highly divergent cardinalid species: A rose-breasted grosbeak () and a scarlet tanager ().

Using low-coverage whole-genome sequencing, analysis of vocalizations, and inferences from natural history, we document a first-generation hybrid between a rose-breasted grosbeak () and a scarlet tanager (). These two species occur sympatrically throughout much of eastern North America, although were not previously known to interbreed. Following the field identification of a putative hybrid, we use genetic and bioacoustic data to show that a rose-breasted grosbeak was the maternal parent and a scarlet tanager was the paternal parent of the hybrid, whose song was similar to the latter species.

Extensive historical and contemporary hybridization suggests premating isolation in warblers is not strong: A reply to Confer et al.

We present comments on an article published by Confer et al. (Ecology and Evolution, 10, 2020). Confer et al.

Molecular assays of pollen use consistently reflect pollinator visitation patterns in a system of flowering plants.

Determining how pollinators visit plants vs. how they carry and transfer pollen is an ongoing project in pollination ecology. The current tools for identifying the pollens that bees carry have different strengths and weaknesses when used for ecological inference.

Signatures of mitonuclear coevolution in a warbler species complex.

Divergent mitonuclear coadaptation could facilitate speciation. We investigate this possibility in two hybridizing species of warblers, Setophaga occidentalis and S. townsendi, in western North America.

Comparing divergence landscapes from reduced-representation and whole genome resequencing in the yellow-rumped warbler (Setophaga coronata) species complex.

Researchers seeking to generate genomic data for non-model organisms are faced with a number of trade-offs when deciding which method to use. The selection of reduced representation approaches versus whole genome resequencing will ultimately affect the marker density, sequencing depth, and the number of individuals that can multiplexed. These factors can affect researchers' ability to accurately characterize certain genomic features, such as landscapes of divergence-how F varies across the genomes.

Barriers to Accessing Kidney Transplantation Among Populations Marginalized by Race and Ethnicity in Canada: A Scoping Review Part 2-East Asian, South Asian, and African, Caribbean, and Black Canadians.

Background: Kidney transplantation (KT), a treatment option for end-stage kidney disease (ESKD), is associated with longer survival and improved quality of life compared with dialysis. Inequities in access to KT, and specifically, living donor kidney transplantation (LDKT), have been documented in Canada, along various demographic dimensions. In this article, we review existing evidence about inequitable access to KT and LDKT for patients from communities marginalized by race and ethnicity in Canada.

Selection on a small genomic region underpins differentiation in multiple color traits between two warbler species.

Speciation is one of the most important processes in biology, yet the study of the genomic changes underlying this process is in its infancy. North American warbler species and hybridize in a stable hybrid zone, following a period of geographic separation. Genomic differentiation accumulated during geographic isolation can be homogenized by introgression at secondary contact, whereas genetic regions that cause low hybrid fitness can be shielded from such introgression.

Pigmentation Genes Show Evidence of Repeated Divergence and Multiple Bouts of Introgression in Setophaga Warblers.

Species radiations have long served as model systems in evolutionary biology. However, it has only recently become possible to study the genetic bases of the traits responsible for diversification and only in a small number of model systems. Here, we use genomes of 36 species of North, Central, and South American warblers to highlight the role of pigmentation genes-involved in melanin and carotenoid processing-in the diversification of this group.

Attitudes and Beliefs Toward Computerized Cognitive Training in the General Population.

Introduction: In recent years, computerized cognitive training (CCT) programs have been developed commercially for widespread public consumption. Despite early enthusiasm, whether these programs enhance cognitive abilities in healthy adults is a contentious area of investigation. Given the mixed findings in the literature, researchers are beginning to investigate how beliefs and attitudes toward CCT impact motivation, expectations, and gains after cognitive training.

Evolution: Speciation by Migratory Drop-Off in Flycatchers.

Identifying the isolating barriers that lead to species formation is challenging. New genomic, phylogenetic and life-history data in Tyrant flycatchers - the largest bird family - suggest long-distance migration contributes to reproductive isolation among closely related forms and to differential diversification across the family.

Anticoagulant Utilization and Direct Oral Anticoagulant Prescribing in Patients with Nonvalvular Atrial Fibrillation.

Background: Direct oral anticoagulants (DOACs) are indicated for prevention of stroke and embolism in patients with nonvalvular atrial fibrillation (NVAF). These agents have been shown to be non-inferior to warfarin in terms of efficacy and safety. However, their uptake in practice has been variable, and prescribed dosages may be inconsistent with manufacturer recommendations.

Selection on linked to migration in a songbird.

Animal migration demands an interconnected suite of adaptations for individuals to navigate over long distances. This trait complex is crucial for small birds whose migratory behaviors-such as directionality-are more likely innate, rather than being learned as in many longer-lived birds. Identifying causal genes has been a central goal of migration ecology, and this endeavor has been furthered by genome-scale comparisons.