Search

Road mortality is identified as a threat to American badger (Taxidea taxus (Schreber, 1777)) populations across Canada. Understanding habitat selection and movement in relation to roads is therefore vital to their conservation. Using telemetry data and road-kill locations of badgers in southwestern Ontario, we examined the relationship between habitat selection, movement patterns, and roads at three spatial scales. At the study-area scale, we assessed the effects of habitat attributes on burrow site selection. Several individuals placed their burrows closer to primary highways than expected, suggesting that badgers are not sensitive to human disturbances at this scale. Using straight-line movement trajectories between burrows, we analyzed individual movement patterns within home ranges. All badgers showed some degree of road avoidance, either crossing fewer roads or roads that posed lower mortality risk. At the road-crossing scale, we compared landscape features surrounding road-kill locations to random locations along the same roadway. There was a positive relationship between road-kill locations and number of water-based linear features and higher density of hedgerow cover. Our results provide evidence that badger movement is influenced by roads at multiple scales, which has important implications for managers interested in developing road-mitigation strategies for this endangered population. Key words: American badger, Taxidea taxus jacksoni, conservation, movement, roads, species at risk, wildlife--vehicle collisions., Resume : La mortalite routiere constitue une menace pour les populations de blaireaux d'Amerique (Taxidea taxus (Schreber, 1777)) partout au Canada. La comprehension de la selection d'habitats et des deplacements [...]

Microbiome diversity and diet composition concomitantly influence species health, fitness, immunity, and digestion. In environments where diet varies spatially and temporally, microbiome plasticity may promote rapid host adaptation to available resources. For northern ungulates in particular, metabarcoding of noninvasively collected fecal pellets presents unprecedented insights into their diverse ecological requirements and niches by clarifying the interrelationships of microbiomes, key to deriving nutrients, in context of altered forage availability in changing climates. Muskoxen (Ovibos moschatus) are Arctic‐adapted species that experience fluctuating qualities and quantities of vegetation. Geography and seasonality have been noted to influence microbiome composition and diversity in muskoxen, yet it is unclear how their microbiomes intersect with diet. Following observations from other species, we hypothesized increasing diet diversity would result in higher microbiome diversity in muskoxen. We assessed diet composition in muskoxen using three common plant metabarcoding markers and explored correlations with microbiome data. Patterns of dietary diversity and composition were not fully concordant among the markers used, yet all reflected the primary consumption of willows and sedges. Individuals with similar diets had more similar microbiomes, yet in contrast to most literature, yielded negative relationships between microbiome and diet alpha diversity. This negative correlation may reflect the unique capacities of muskoxen to survive solely on high‐fiber Arctic forage and provide insight into their resiliency to exploit changing dietary resources in a rapidly warming Arctic altering vegetation diversity. [ABSTRACT FROM AUTHOR]

Southeastern Canada is inhabited by an amalgam of hybridizing wolf-like canids, raising fundamental questions regarding their taxonomy, origins, and timing of hybridization events. Eastern wolves (Canis lycaon), specifically, have been the subject of significant controversy, being viewed as either a distinct taxonomic entity of conservation concern or a recent hybrid of coyotes (C. latrans) and grey wolves (C. lupus). Mitochondrial DNA analyses show some evidence of eastern wolves being North American evolved canids. In contrast, nuclear genome studies indicate eastern wolves are best described as a hybrid entity, but with unclear timing of hybridization events. To test hypotheses related to these competing findings we sequenced whole genomes of 25 individuals, representative of extant Canadian wolf-like canid types of known origin and levels of contemporary hybridization. Here we present data describing eastern wolves as a distinct taxonomic entity that evolved separately from grey wolves for the past ∼67,000 years with an admixture event with coyotes ∼37,000 years ago. We show that Great Lakes wolves originated as a product of admixture between grey wolves and eastern wolves after the last glaciation (∼8,000 years ago) while eastern coyotes originated as a product of admixture between "western" coyotes and eastern wolves during the last century. Eastern wolf nuclear genomes appear shaped by historical and contemporary gene flow with grey wolves and coyotes, yet evolutionary uniqueness remains among eastern wolves currently inhabiting a restricted range in southeastern Canada. [ABSTRACT FROM AUTHOR]

We review the role of biogeochemical signatures, such as stable isotopes and trace elements, in the cornified claw tissue as a means of studying movement and foraging behaviour of vertebrates because this approach is noninvasive and can capture contemporary and historic signatures. Because biogeochemical techniques are still relatively new in studies of animal movement, we are only beginning to understand how the growth patterns of the cornified claw sheath may affect our ability to interpret the biogeochemical signals in these tissues. To move towards resolving this, we review the morphology of the epidermal cornified claw sheath in several taxa that illustrate substantial variation in growth patterns both between taxa and between individual distinct claw regions. For instance, in mammalian claws, deposition of keratinizing cells from the epidermis is nonlinear because the claw tip is composed of old and new cornified epidermal cells, whereas the cornified blade horn covering the claw's lateral walls is deposited continuously and without assortment, providing unbroken time-series data. We also consider patterns of growth in mammalian hooves, as well as reptilian, avian, and amphibian cornified claw sheaths, and address the need for expanded research in this field. We conclude this synthesis by describing a noninvasive technique for monitoring growth rates in a model mammal, the American badger {Taxidea taxus (Schreber, 1777)), and provide guidelines for future sampling of claw keratin, which will improve our ability to back-calculate the time of biogeochemical integration into this tissue. Nous faisons une revue du role des signatures biogeochimiques, telles que les isotopes stables et les elements en traces, dans le tissu corne des griffes comme moyens d'etudier les deplacements et le comportement alimentaire chez les vertebres, puisqu'il s'agit d'une methodologie non invasive qui peut retenir des signatures actuelles et passees. Puisque les techniques biogeochimiques sont d'usage relativement recent dans les etudes des deplacements animaux, nous commencons tout juste a comprendre comment les patrons de croissance de l'etui corne des griffes peuvent affecter notre capacite a interpreter les signaux biogeochimiques dans ces tissus. Pour faire du progres dans ce domaine, nous passons en revue la morphologie de l'etui corne epidermique de la griffe chez divers taxons, ce qui revele une importante variation dans les patrons de croissance, tant entre les taxons qu'entre les differentes regions distinctes de la griffe. Par exemple, dans les griffes de mammiferes, la deposition des cellules keratinisantes par l'epiderme ne se fait pas de facon lineaire parce que la pointe de la griffe est composee de cellules epidermiques cornees anciennes et recentes, alors que la lame cornee qui couvre les parois laterales de la griffe est deposee de maniere continue et sans assortiment, ce qui fournit une serie chronologique continue. Nous examinons aussi les patrons de croissance des sabots de mammiferes et des etuis cornes des griffes de reptiles, d'oiseaux et d'amphibiens. Nous terminons notre synthese en decrivant une technique non invasive pour suivre les taux de croissance chez un mammifere modele, le blaireau d'Amerique (Taxhka taxus (Schreber, 1777)), et fournissant des regles pour l'echantillonnage futur de la keratine des griffes, qui permettront d'ameliorer notre capacite de retrocalculer le moment de l'integration biogeochimique dans ce tissu. [Traduit par la Redaction], Introduction Understanding movement and foraging behaviour of animals on a daily, seasonal, or annual basis is fundamental to ecological, evolutionary, and conservation studies. Until recently, studying animal movement required trapping [...]

Low genetic diversity is associated with low fitness and evolutionary potential, yet the demographic and life-history traits of some species contribute to low genetic diversity, without empirical evidence of negative impacts on fitness. Modelling past and future trajectories of genetic diversity under different demographic scenarios can provide insight into how genetic variation might impact population fitness. The muskox is an Arctic species that has undergone multiple population bottlenecks and, although populations have rebounded repeatedly, two large populations have recently declined by > 50%. It is unclear how these demographic patterns influence muskox genetic diversity and fitness. We compared the genetic diversity of Canadian muskox populations undergoing opposing population trends. Genotyping 84 mainland and 244 Victoria Island individuals at ten microsatellite loci revealed low genetic variation (Victoria Island, mean allelic richness 1.66, expected heterozygosity 0.16; mainland, mean allelic richness 2.58, expected heterozygosity 0.41), with no evidence of further reductions in diversity subsequent to recent demographic declines. Bayesian modelling showed that a 1900s bottleneck contributed to the lack of diversity in contemporary populations, and forward-in-time simulations suggested little effect on genetic diversity over the next 100 years. Muskoxen might have reached a genetic diversity minimum, and additional research will be needed to determine their capacity to adapt to rapid changes in selective pressures in a rapidly changing Arctic. [ABSTRACT FROM AUTHOR]

The current genetic structure of fisher population in an area of southern Ontario which has recently recolonized was examined. Results concluded that Algonquin Park fisher population has not been a substantial source for recolonization, expansion, but occurred from a number of remnant populations within Ontario, Quebec, and recently from Adirondacks in New York.