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Capturing and handling wildlife is a common practice for both management and research. As telemetry use has become common, the need to capture and chemically immobilize wildlife has increased. Understanding how long the effects of immobilizing agents last after releasing the animal is often poorly understood but needed to ensure that analyses use data that reflect natural behavior. Between 2016 and 2021, 60 cougars (Puma concolor) were chemically immobilized with medetomidine, zolazepam, and tiletamine (MZT) and collared across west-central Alberta, Canada, 27 of which were individuals being recollared. We examined the distance an individual traveled per day and compared equivalent periods before and after the recollaring event to determine whether postcapture movement rates were significantly different from precapture rates. Within 1 d of the recollaring, daily movement rates had returned to precapture rates (t20-2.09, P=0.18). Our results provide insight on how MZT used in cougars affects their postcapture movement and thus may be helpful in interpreting movement data after release. [ABSTRACT FROM AUTHOR]

Polar bear (Ursus maritimus) life history is intimately associated with the distribution of sea ice and their prey in Arctic ecosystems. These ecosystems are changing in response to climate warming, resulting in the increased prevalence of pathogens in polar bears. Erysipelothrix rhusiopathiae has a long history of infection in domestic species and more recently in wildlife in the Canadian Arctic. As a result of increasing reports of E. rhusiopathiae causing morbidity and mortality in Arctic terrestrial mammals, we tested the seroprevalence of E. rhusiopathiae in Beaufort Sea polar bears sampled in 1985-87, 1992, 1994, and 2003-11. Our sample of 180 polar bears (117 females, 61 males, two unknown) with a median age of 9 yr (range 1-26 yr) had a seropositivity of 27.2% (49/180 individuals). We used binomial logistic regressions to investigate biotic and abiotic factors that may be linked to seropositivity. The resulting top model found that increased predation on adult ringed seals (Pusa [Phoca] hispida) and negative winter Arctic Oscillation Index (AOI) years were associated with a higher probability of seropositivity. Ringed seals may be a reservoir for E. rhusiopathiae via their consumption of infected prey, as the pathogen can persist in marine fish, molluscs, and crustaceans. Negative winter AOIs in our data set reflected high ice volume years, which reduced ringed seal natality, resulting in fewer seal pups available as prey. Our results suggest that exposure to E. rhusiopathiae in Beaufort Sea polar bears is modulated by a predator-prey mechanism., (© Wildlife Disease Association 2024.)