Northern Canada is warming at 3 times the global rate. Thus, changing diversity and distribution of vectors and pathogens is an increasing health concern. California serogroup (CSG) viruses are ...mosquitoborne arboviruses; wildlife reservoirs in northern ecosystems have not been identified. We detected CSG virus antibodies in 63% (95% CI 58%-67%) of caribou (n = 517), 4% (95% CI 2%-7%) of Arctic foxes (n = 297), 12% (95% CI 6%-21%) of red foxes (n = 77), and 28% (95% CI 24%-33%) of polar bears (n = 377). Sex, age, and summer temperatures were positively associated with polar bear exposure; location, year, and ecotype were associated with caribou exposure. Exposure was highest in boreal caribou and increased from baseline in polar bears after warmer summers. CSG virus exposure of wildlife is linked to climate change in northern Canada and sustained surveillance could be used to measure human health risks.
Effect of skull morphology on fox snow diving Yuk, Jisoo; Pandey, Anupam; Park, Leena ...
Proceedings of the National Academy of Sciences - PNAS,
2024-May-07, 2024-05-07, 20240507, Volume:
121, Issue:
19
Journal Article
Peer reviewed
Certain fox species plunge-dive into snow to catch prey (e.g., rodents), a hunting mechanism called mousing. Red and arctic foxes can dive into snow at speeds ranging between 2 and 4 m/s. Such ...mousing behavior is facilitated by a slim, narrow facial structure. Here, we investigate how foxes dive into snow efficiently by studying the role of skull morphology on impact forces it experiences. In this study, we reproduce the mousing behavior in the lab using three-dimensional (3D) printed fox skulls dropped into fresh snow to quantify the dynamic force of impact. Impact force into snow is modeled using hydrodynamic added mass during the initial impact phase. This approach is based on two key facts: the added mass effect in granular media at high Reynolds numbers and the characteristics of snow as a granular medium. Our results show that the curvature of the snout plays a critical role in determining the impact force, with an inverse relationship. A sharper skull leads to a lower average impact force, which allows foxes to dive head-first into the snow with minimal tissue damage.
In her provocative politics, which confront us still with the complexities of left and right, and her constant search for her place in the world, Fox-Genovese’s story resonates more strongly than ...ever.
Sarcoptic mange caused by Sarcoptes scabiei can have catastrophic consequences for wildlife. We inspected 122 Andean foxes (Lycalopex culpaeus), collected by active (n=66) or passive (n=56) ...surveillance, and 28 South American gray foxes (Lycalopex griseus; all from passive surveillance) for mange in Chile (2015-19). In Andean foxes, gross lesions of mange were diagnosed in 24% of passively and 9% of actively collected foxes, although observed prevalences might be underestimated. Seroprevalence was 37 and 18%, respectively, indicating that some individuals recovered from infection or were developing the disease. No differences were found between age and sex groups. Comparing data from passive surveillance, occurrence of gross lesions was lower in gray foxes (5%). Body condition was significantly better in Andean foxes without lesions than in diseased foxes, which had significantly lower albumin concentrations than healthy individuals. Among the 12 foxes with gross lesions, four, six and two individuals were categorized as having type I, type II, and type III lesions, respectively, based on clinical severity. Histologic severity correlated with gross lesions and included irregular epidermal hyperplasia with hyperkeratosis, which was marked in type II and III infections. Conventional PCR targeting of the cox1 gene fragment revealed four nucleotide sequence types, showing 99-100% identity among them and between 99% and 100% identity with previously published sequences of S. scabiei. A significant association between the occurrence of mange in foxes and distance to the nearest house was found. We speculate that diseased foxes tended to approach human settlements, perhaps in search of food. Visual inspection of 211 rural dogs from the study area did not reveal gross mange lesions in any animal. Sarcoptic mange is enzootic in the Andean fox in the study area and should be considered in the management of the species.
Climate warming is favoring the expansion of non-native species onto the Arctic tundra, where they may compete over resources with native species. In the harsh tundra conditions, sympatric red foxes ...(Vulpes vulpes) and Arctic foxes (Vulpes lagopus) may compete over denning sites, which are important for their reproduction and survival. We studied den selection by red and Arctic foxes in spring and summer and their possible competition over this resource in an ecotone near Churchill, Manitoba, on the west coast of Hudson Bay, by examining patterns of den occupancy related to den characteristics and spacing patterns between neighbors. Based on 11 years of occupancy data for 42 tundra dens, we determined that red and Arctic foxes favored dens based on shelter quality in both spring and summer, rather than proximity of specific habitats (and thus specific prey). Mechanisms of den selection differed between species, which may promote coexistence, and areas of high den density were avoided by red foxes and preferred by Arctic foxes. We did not find evidence of exclusion of Arctic foxes by red foxes: spacing patterns showed that foxes spaced themselves based on their need for space, territoriality and food availability but not interference. In the current abiotic Arctic conditions, taiga species settling on the tundra could coexist with tundra endemics, at given density thresholds of both competitors. As Arctic conditions may become milder, an increase in newcomer abundance could disrupt the current balance that favors species coexistence.
Native only to the California Channel Islands, the island fox is the smallest canid in North America. Populations on four of the islands were threatened to extinction in the 1990s due to ...human-mediated predation and disease. This is the first account of the natural history and ecology of the island fox, illustrating both the vulnerability of island ecosystems and the efficacy of cooperative conservation measures. It explains in detail the intense conservation actions required to recover fox populations, such as captive breeding and reintroduction, and large-scale ecosystem manipulation. These actions were successful due in large part to extraordinary collaboration among the scientists, managers and public advocates involved in the recovery effort. The book also examines the role of some aspects of island fox biology, characteristic of the 'island syndrome', in facilitating their recovery, including high productivity and an apparent adaptation to periodic genetic bottlenecks.
The Russian Farm-Fox Experiment is the best known experimental study in animal domestication. By subjecting a population of foxes to selection for tameness alone, Dimitry Belyaev generated foxes that ...possessed a suite of characteristics that mimicked those found across domesticated species. This ‘domestication syndrome’ has been a central focus of research into the biological pathways modified during domestication. Here, we chart the origins of Belyaev’s foxes in eastern Canada and critically assess the appearance of domestication syndrome traits across animal domesticates. Our results suggest that both the conclusions of the Farm-Fox Experiment and the ubiquity of domestication syndrome have been overstated. To understand the process of domestication requires a more comprehensive approach focused on essential adaptations to human-modified environments.
The ‘domestication syndrome’ has been a central focus of research into the biological processes underlying domestication. The Russian Farm-Fox Experiment was the first to test whether there is a causal relationship between selection for tameness and the domestication syndrome.Historical records and genetic analysis show that the foxes used in the Farm-Fox Experiment originated from fur farms in eastern Canada and that most traits attributed to the behavioral selection for tameness predated the experiment, undermining a central pillar of support for the domestication syndrome.The overall weight of evidence, including data from other species, does not unambiguously support the existence of the domestication syndrome in animals. Competing theories to explain domestication syndrome should be reconsidered after the traits themselves are more clearly connected to the early stages of domestication.
Susceptibility of Wild Canids to SARS-CoV-2 Porter, Stephanie M; Hartwig, Airn E; Bielefeldt-Ohmann, Helle ...
Emerging infectious diseases,
09/2022, Volume:
28, Issue:
9
Journal Article
Peer reviewed
Open access
We assessed 2 wild canid species, red foxes (Vulpes vulpes) and coyotes (Canis latrans), for susceptibility to SARS-CoV-2. After experimental inoculation, red foxes became infected and shed ...infectious virus. Conversely, experimentally challenged coyotes did not become infected; therefore, coyotes are unlikely to be competent hosts for SARS-CoV-2.
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