Female birds transfer maternally-derived antibodies (matAb) to their nestlings, via the egg yolk. These antibodies are thought to provide passive protection, and allow nestlings to avoid the costs associated with mounting an innate immune response. To test whether there is an energetic benefit to nestlings of receiving matAb, we challenged adult female tree swallows (Tachycineta bicolor) prior to clutch initiation with either lipopolysaccharide (LPS) or saline (Control). Following hatching, one half of each females nestlings...

Researchers increasingly rely on non-invasive physiological indices, such as glucocorticoid (GC) levels, to interpret how vertebrates respond to changes in their environment. Recently, hair GCs have been of particular interest, because they are presumed stable over long periods of storage, which may facilitate the study of large-scale spatial and temporal patterns of stress in mammals. In the current study, we evaluated the stability of hair corticosterone levels in museum specimens, and the potential effects of...

1. Dissemination of oral vaccine baits is a cost-effective method to contain and control infectious wildlife diseases. The effectiveness of vaccine barriers in slowing or halting the disease spread depends on host ecology and landscape variability. It is not clear, however, how the success of vaccine barriers to manage disease may change from an epizootic to an enzootic phase of a disease invasion, and if this depends on the quality and configuration of host habitat....

Mylodon darwinii is the extinct giant ground sloth named after Charles Darwin, who first discovered its remains in South America. We have successfully obtained a high-quality mitochondrial genome at 99-fold coverage using an Illumina shotgun sequencing of a 12,880 year-old bone fragment from Mylodon Cave in Chile. Low level of DNA damage showed that this sample was exceptionally well preserved for an ancient sub-fossil, likely the result of the dry and cold conditions prevailing within...

Human societies depend on an Earth System that operates within a constrained range of nutrient availability, yet the recent trajectory of terrestrial nitrogen (N) availability is uncertain. Examining patterns of foliar N concentrations ([N]) and isotope ratios (15N) from more than 42,000 samples acquired over 37 years, here we show that foliar [N] declined by 8% and foliar 15N declined by 0.8 – 1.9 ‰. Examining patterns across different climate spaces, foliar 15N declined across...

1. Prey abundance and prey vulnerability vary across space and time, but we know little about how they mediate predator-prey interactions and predator foraging tactics. To evaluate the interplay between prey abundance, prey vulnerability, and predator space use, we examined patterns of black bear (Ursus americanus) predation of caribou (Rangifer tarandus) neonates in Newfoundland, Canada using data from 317 collared individuals (9 bears, 34 adult female caribou, 274 caribou calves). 2. During the caribou calving...

One proposed advantage of communal roosting in birds is a reduction in the costs of thermoregulation. As thermoregulatory benefits are directly linked to the distance between roosting birds, we examined whether temperature is related to inter‐bird spacing in roosting chimney swifts (Chaetura pelagica). To test the hypothesis that huddling is used to reduce the costs of thermoregulation, we predicted that swifts would cluster more at colder temperatures. We mounted an all‐weather camera atop a 61...

Understanding population-level effects of environmental stressors on aquatic biota requires knowledge of the direct adverse effects of pollutants on individuals and species interactions that relate to survival and reproduction. Here, we connect behavioral assays with survival trials and a modeling approach to quantify changes in antipredator escape performance of a larval freshwater fish following exposure to an environmental estrogen, and predict changes in population abundance. We quantified the effects of short-term (21 d) exposure to...

1. Understanding an organism’s habitat selection and behavioural flexibility in the face of environmental change can help managers plan for future conservation of that species. Hyperabundant tundra-nesting geese are influencing Arctic environments through their foraging activities. Goose-induced habitat change in Arctic wetlands may influence the availability of habitat for numerous shorebird species that breed sympatrically with geese. 2. Here, we explore whether goose-induced habitat alteration affects shorebird breeding density and nest-site selection. Using habitat data...

1. Distance sampling (DS) is a widely-used framework for estimating animal abundance. DS models assume that observations of distances to animals are independent. Non-independent observations introduce overdispersion, causing model selection criteria such as AIC or AICc to favour overly complex models, with adverse effects on accuracy and precision. 2. We describe, and evaluate via simulation and with real data, estimators of an overdispersion factor (c ̂), and associated adjusted model selection criteria (QAIC) for use...

Aerial insectivores are highly mobile predators that feed on diverse prey items that have highly variable distributions. As such, investigating the diet, prey selection, and prey availability of aerial insectivores can be challenging. In this study, we used an integrated DNA barcoding method to investigate the diet and food supply of Barn Swallows, an aerial insectivore whose North American population has declined over the past 40 years. We tested the hypotheses that Barn Swallows are...

Isolation-by-distance (IBD) is a natural pattern not readily incorporated into theoretical models nor traditional metrics for differentiating populations, although clinal genetic differentiation can be characteristic of many wildlife species. Landscape features can also drive population structure additive to baseline IBD resulting in differentiation through isolation-by-resistance (IBR). We assessed the population genetic structure of boreal caribou across western Canada using non-spatial (STRUCTURE) and spatial (MEMGENE) clustering methods and investigated the relative contribution of IBD and IBR...

Harvesting can induce rapid evolution in animal populations, yet the role of ecological change in buffering or enhancing that response is poorly understood. Here, we developed an eco-genetic model to examine how ecological changes brought about by two notorious invasive species – zebra and quagga mussels– influence harvest-induced evolution and resilience in a freshwater fish. Our study focused on lake whitefish (Coregonus clupeaformis) in the Laurentian Great Lakes, where the species supports valuable commercial and...

Range expansion is a widespread biological process, with well described theoretical expectations for the genomic outcomes accompanying the colonization of novel ranges. However, comparatively few empirical studies address the genome-wide consequences associated with the range expansion process, particularly in recent or on-going expansions. Here, we assess two recent and distinct eastward expansion fronts of a highly mobile carnivore, the coyote (Canis latrans), to investigate patterns of genomic diversity and identify variants that may have been...