Biology subjects

Winger, B. M.

Publications and source records attributed to Winger, B. M..

5 recordsLinked to original sources

bioRxiv2024

Distinct intraspecific diversification dynamics in Neotropical montane versus lowland birds revealed by whole-genome comparative phylogeography

Comparing phylogeographic patterns across different biogeographic regions can illuminate how different types of landscapes promote the formation of incipient species, providing insights into the evolutionary mechanisms underlying broadscale biodiversity gradients. The Neotropics are a global biodiversity hotspot, and the megadiverse Andes-Amazonia system has elevational gradients in both species richness and speciation rates. Here, we compare the phylogeographic dynamics of birds in the tropical Andes mountains versus the Amazonian lowlands using whole genomes from a congeneric set of colorful canopy frugivores (Tangara tanagers). We first show that Andean species have greater population structuring across their geographic ranges than Amazonian species. Next, we evaluated whether differences in geographic barrier efficacy and range size drive this elevated population-level divergence in the mountains. We find greater population differentiation and reduced gene flow across individual geographic barriers in the Andes. Furthermore, Andean species have consistently lower genetic diversity and smaller effective population sizes. Together, these results support a model of Neotropical diversification whereby incipient species form more readily in the mountains than the lowlands owing to more effective geographic barriers and smaller populations. These different phylogeographic processes across the Andes-Amazonia system carry implications for our understanding of the origin and maintenance of regional biodiversity gradients.

evolutionary biology↗

bioRxiv2024

Evolutionary integration of the geography and pacing of the annual cycle in migratory birds

In migratory species, the temporal phases of the annual cycle are intrinsically linked to seasonally shifting geographic ranges. Despite intense interest in the annual cycle ecology of migration, a synthetic understanding of the relationship between the biogeography and phenology of seasonal migration remains elusive. Here, we interrogate the spatiotemporal structure of the annual cycle in a novel phylogenetic comparative framework. We use eBird, a massive avian occurrence dataset, to demarcate and measure in a consistent manner among species the portions of the annual cycle when a geographic distribution is stationary versus dynamic due to migration. Through comparative analyses of the durations of annual cycle stages for 150 species of migratory birds breeding in North America, we show that the duration of the migratory periods is remarkably consistent among species and is unrelated to the distance between breeding and nonbreeding locations. In other words, the seasonal distributions of long-distance migrants shift between their geographically distant stationary phases in the same amount of time as short-distance migrants, suggesting that individuals of long-distance migratory species have more synchronous periods of migration and likely a faster individual migratory pace than short-distance migrants. Our results further show that the amount of time a species spends on the breeding grounds is strongly inversely related to time spent on the nonbreeding grounds, revealing the length of the breeding versus nonbreeding stationary period to be the primary source of species-level variation in the pacing of the annual cycle, as opposed to the time needed for the migratory period. Further, our study reveals that the amount of time spent annually on the breeding versus nonbreeding grounds predicts the distance between breeding and nonbreeding locations, demonstrating key linkages between the biogeography of the migratory cycle, its phenology, and the evolution of life history tradeoffs.

ecology↗

bioRxiv2023

The pace of mitochondrial molecular evolution varies with seasonal migration distance

Animals that engage in long-distance seasonal migration experience strong selective pressures on their metabolic performance and life history, with potential consequences for molecular evolution. Species with slow life histories typically show lower rates of synonymous substitution (dS) than "fast" species. Previous work has suggested that long-distance seasonal migrants have a slower life history strategy than short-distance migrants, raising the possibility that rates of molecular evolution may covary with migration distance. Additionally, long-distance migrants may face strong selection on metabolically important mitochondrial genes owing to their long-distance flights. Using over 1000 mitochondrial genomes, we assessed the relationship between migration distance and mitochondrial molecular evolution in 39 boreal-breeding migratory bird species. We show that migration distance correlates negatively with dS, suggesting that the slow life history associated with long-distance migration is reflected in rates of molecular evolution. Mitochondrial genes in every study species exhibited evidence of purifying selection, but the strength of selection was greater in short-distance migrants, contrary to our predictions. This result may indicate selection for cold tolerance on mitochondrial evolution among species overwintering at high latitudes. Our study demonstrates that the pervasive correlation between life history and molecular evolutionary rates exists in the context of differential adaptations to seasonality.

evolutionary biology↗

bioRxiv2020

Flight morphology and visual obstruction predict collision risk in birds

Collisions with buildings are a major source of mortality for wild birds, but these instantaneous events are difficult to observe. As a result, the mechanistic causes of collision mortality are poorly understood. Here, we evaluate whether sensory and biomechanical traits can explain why some species are more collision-prone than others. We first examined concordance of species vulnerability estimates across previous North American studies to determine whether these estimates are repeatable, and whether vulnerability is more similar among closely-related species. We found moderate concordance and phylogenetic signal, indicating that some bird species are consistently more collision-prone than others. We next tested whether morphological traits related to flight performance and sensory guidance explain these differences among species. Our comparative analysis shows that two traits primarily predict collision vulnerability within passerines: relative beak length and relative wing length. Small passerine species with relatively short wings and those with relatively long beaks are more collision-prone, suggesting that greater maneuverability and obstructed vision contribute to risk. Together, these findings can help inform mitigation strategies and predict which species will be most at risk in other regions.

animal behavior and cognition↗

bioRxiv2019

Shared morphological consequences of global warming in North American migratory birds

Increasing temperatures associated with climate change are predicted to cause reductions in body size, a key determinant of animal physiology and ecology. Using a four-decade specimen series of 70,716 individuals of 52 North American migratory bird species, we demonstrate that increasing annual summer temperature over the 40-year period drove consistent reductions in body size across these diverse taxa. Concurrently, wing length - which impacts nearly all aspects of avian ecology and behavior - has consistently increased across taxa. Our findings suggest that warming-induced body size reduction is a general response to climate change, and reveal a similarly consistent shift in an ecologically-important dimension of body shape. We hypothesize that increasing wing length represents a compensatory adaptation to maintain migration as reductions in body size have increased the metabolic cost of flight. An improved understanding of warming-induced morphological changes, and their limits, are important for predicting biotic responses to global change.

ecology↗