Biology subjects

Butcher, B. G.

Publications and source records attributed to Butcher, B. G..

3 recordsLinked to original sources

bioRxiv2025

Seeking smarts: Male chickadees with better spatial cognition sire more extra-pair young

Across animal taxa, females commonly mate with more than one male, even in monogamous mating systems. These extra-pair (EP) copulations and resulting young may increase the fitness of the female via a variety of mechanisms. The "good genes" hypothesis suggests that socially monogamous females mate outside their pair bond to increase the fitness of their offspring via indirect genetic benefits, because extra-pair males do not provide parental care. We tested this hypothesis by quantifying extra-pair paternity in nonmigratory, food-caching mountain chickadees (Poecile gambeli). Chickadees rely on spatial cognition to recover scattered food caches and variation in spatial cognition is associated with increased survival, longer lifespan, and is heritable. However, less is known about the role of sexual selection on spatial cognitive abilities. In the current study, we found that 1. males with better spatial cognitive abilities sired more extra-pair young and produce heavier offspring in their own nests compared to their poorer performing counterparts, and 2. extra-pair males had significantly better spatial cognition than the social males they cuckolded. These results suggest that sexual selection shapes the evolution of spatial cognition in food-caching chickadees and are consistent with the good genes hypothesis, which posits that females gain indirect genetic benefits via extra-pair young.

animal behavior and cognition↗

bioRxiv2025

Recent divergence and microgeographic genetic structure in an endangered Australian songbird: the southern black-throated finch

Anthropogenic habitat loss and climate change threaten global biodiversity. Effective conservation management requires a detailed understanding of geographic structure, genetic diversity, and demography of threatened species. The black-throated finch, Poephila cincta, is an Australian songbird with two subspecies: atropygialis and cincta. The southern subspecies, cincta, has experienced an [~]80% range contraction over the last century and is listed as endangered but genetic surveys of it are incomplete. Here, we use a combination of reduced representation and whole genome sequencing to examine genetic differentiation, spatial genetic structure, and demographic history in both forms of this species. We find that atropygialis and cincta are genetically distinct despite a history of divergence with gene flow and geographically isolated by a biogeographic barrier known as the Einasleigh Uplands. Since they last shared a common ancestor [~]400,000 years ago, the two subspecies have experienced distinct demographic trajectories: population expansion in atropygialis and population decline in cincta. We find that the two remnant population centers of cincta, from the Galilee Basin and the Townsville Coastal Plain, each represent genetically distinct lineages that last shared appreciable levels of gene flow [~]4,000 years ago. Moreover, we report striking microgeographic genetic structure from the Townsville Coastal Plain between populations <20 km apart associated with barriers to dispersal caused by anthropogenic habitat modification over the last 50 years: namely the construction of the Ross River Dam. Our findings highlight the urgent need for a conservation approach that prioritizes habitat restoration to re-establish population connectivity in the endangered southern black-throated finch.

evolutionary biology↗

bioRxiv2017

Double-digest RAD sequencing outperforms microsatellite loci at assigning paternity and estimating relatedness: a proof of concept in a highly promiscuous bird

Information on genetic relationships among individuals is essential to many studies of the behavior and ecology of wild organisms. Parentage and relatedness assays based on large numbers of SNP loci hold substantial advantages over the microsatellite markers traditionally used for these purposes. We present a double-digest restriction site-associated DNA sequencing (ddRAD-seq) analysis pipeline that, as such, simultaneously achieves the SNP discovery and genotyping steps and which is optimized to return a statistically powerful set of SNP markers (typically 150-600 after stringent filtering) from large numbers of individuals (up to 240 per run). We explore the tradeoffs inherent in this approach through a set of experiments in a species with a complex social system, the variegated fairy-wren (Malurus lamberti), and further validate it in a phylogenetically broad set of other bird species. Through direct comparisons with a parallel dataset from a robust panel of highly variable microsatellite markers, we show that this ddRAD-seq approach results in substantially improved power to discriminate among potential relatives and considerably more precise estimates of relatedness coefficients. The pipeline is designed to be universally applicable to all bird species (and with minor modifications to many other taxa), to be cost- and time-efficient, and to be replicable across independent runs such that genotype data from different study periods can be combined and analyzed as field samples are accumulated.

animal behavior and cognition↗