We undertook a large-scale survey of the distribution of northern, Glaucomys sabrinus (Shaw, 1801), and southern, Glaucomys volans (L., 1758), flying squirrels in Ontario, Canada. Livetrapping was conducted along a northsouth transect spanning about 500 km, from 42.5°N to 47.2°N. During 2002-2004, we conducted 42 971 trap-nights at 26 sites and captured 232 northern and 538 southern flying squirrels. During 2002 and 2003, southern flying squirrels occurred >200 km farther north than we expected. However, the range of this species appeared to contract to the south by about 240 km after the winter of 2004. Weather and food data suggested that cold temperatures during January and February 2004 combined with a failed mast crop in the autumn of 2003 resulted in an energetic bottleneck and subsequent population crash. We speculate that prior to 2004 southern flying squirrels had expanded their geographic range in response to recent climate warming. In particular, the nine winters between 1994 and 2004 were relatively warm. By measuring the range expansion over this warm interval, we were able to estimate a rate of spread of 22 km per year, and a diffusion coefficient of 6.9 × 10 7 m 2 per generation.
Long-term physiological stress in individual animals may be an important mechanism linking ecological change with impaired wildlife population health. In the Southern Hudson Bay (SH) subpopulation of polar bears (Ursus maritimus), increasing stress associated with climate warming may be related to declining body condition. Accordingly, the development of tools to assess long-term stress in this species may prove invaluable for conservation efforts in this threatened population. The measurement of hair cortisol concentration (HCC) has shown promise as a potential biomarker of long-term stress in free-ranging bears. However, to serve as a useful management tool, factors influencing HCC in polar bears must be identified and then revealed to establish linkages between environmental conditions and the fitness of individual animals. We determined HCC (median ¼ 0.48 pg/mg [range ¼ 0.16-2.26 pg/mg]) in 185 polar bears captured in southern Hudson Bay from 2007 to 2009. HCC was influenced by sex, family group status, and capture period but not by body region or hair type. Using models developed through a combination of hypothesis testing and information theory, we also determined that HCC was negatively associated with growth indices (length, mass, and body condition index) linked to fitness in polar bears. Additional research will be required across several polar bear populations to establish the utility of HCC as a tool for polar bear conservation. ß 2012 The Wildlife Society.
Although some populations remain stable, moose (Alces alces) density and distribution have been declining in many areas along the southern edge of their North American distribution. During 2006–2009, we deployed 99 vaginal implant transmitters (VITs) in 86 adult female moose in central Ontario, Canada to assist in locating and radiocollaring neonatal moose calves. We monitored radiocollared calves to estimate calf survival and assess the relative importance of specific causes of death. Calves in the western portion of our study area (WMU49) were exposed to a 6‐day general hunting season, whereas calves in the eastern portion of our study area (Algonquin Provincial Park [APP]) were not exposed to hunting. Annual survival for 87 collared calves was greater in the protected area than the harvested area (72.4 ± 6.8% and 55.8 ± 8.3%, respectively) and averaged 63.7 ± 7.1% overall. Predation by wolves (Canis sp.) and American black bears (Ursus americanus) was the dominant cause of death but occurred predominately in APP, whereas other natural mortality agents were 4× more common in WMU49. Only 16% of the collared calves in WMU49 were harvested each year despite a high proportion (approx. 50%) of accessible, public land. Most natural mortality occurred prior to the autumn hunting season such that reductions in natural mortality had little potential to compensate for calf harvest. Overall, calf survival in our study area was moderate to high and our findings suggest predator control or further restrictions of calf hunting in this area is not justified. © The Wildlife Society, 2013
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.