36 research outputs found
Does Predation Influence the Seasonal and Diel Timing of Moose Calving in Central Ontario, Canada?
Birth synchrony is well documented among ungulates and is hypothesised to maximize neonate survival, either by minimizing the risk of predation through predator swamping or by synchronising birthing with increased seasonal food availability. We used encapsulated vaginal implant transmitters to locate and capture neonatal moose calves and document the seasonal and diel timing of parturition in two adjacent study areas with different predation pressure in central Ontario, Canada. We tested the hypothesis that predation promotes earlier and more synchronous birth of moose calves. Across both areas, proportionately more births occurred during the afternoon and fewer than expected occurred overnight. Mean date of calving averaged 1.5 days earlier and calving was also more synchronous in the study area with heavier predation pressure, despite average green-up date and peak Normalized Difference Vegetation Index date occurring 2 days later in this study area than in the area receiving lighter predation pressure. We encourage analysis of data on timing of parturition from additional study areas experiencing varying degrees of predation pressure to better clarify the influence of predation in driving seasonal and diel timing of parturition in temperate ungulate
Temporal variation in food habits of the American Black Bear (Ursus americanus) in the boreal forest of northern Ontario
We used scat analysis to investigate temporal variation in the food habits of American Black Bears (Ursus americanus) in the boreal forest of northern Ontario. Specifically, we examined whether there was a seasonal shift in foraging over three years (1990–1992) and which foods, if any, varied in occurrence among years. American Black Bears ate foods ranging from green vegetation in the spring to ants in mid-summer and berries and nuts in late summer and fall. Late summer berry forage, especially blueberries (Vaccinium spp.), varied greatly among years. American Black Bears in northern Ontario consumed a variety of foods opportunistically. Understanding how American Black Bears in northern Ontario exploit food resources and how these food items vary among years can provide insights into demographic processes and help wildlife managers better anticipate changes in the structure of the harvest of American Black Bears and in human–bear conflict levels. In northern Ontario, forest management practices that increase the availability of early successional species would be beneficial to American Black Bear populations
Traditional Ecological Knowledge of Polar Bears in the Northern Eeyou Marine Region, Québec, Canada + Supplementary Appendix 1 (See Article Tools)
Polar bears are important socio-cultural symbols in the communities of the Eeyou Marine Region (EMR) in northwestern Québec, Canada. Members of the Cree communities in this region are generally not active polar bear hunters, but they encounter polar bears when fishing, trapping, or hunting during the ice-free season. A growing body of scientific evidence suggests that reduced annual sea ice cover in Hudson Bay has led to declines in body condition of polar bears in the local Southern Hudson Bay subpopulation and to a population decline in the neighboring Western Hudson Bay subpopulation. In June 2012, we conducted 15 semi-directed interviews on the subject of polar bear biology and climate change with local elders and hunters in three communities in the northern EMR: Wemindji, Chisasibi, and Whapmagoostui. The interviews held in Whapmagoostui included informants from Kuujjuarapik, the adjacent Inuit community. The interviews addressed knowledge gaps in the Recovery Strategy for Polar Bear in Ontario. Transcripts of the interviews were coded thematically and analyzed using both qualitative and quantitative methods. The interviews revealed important insights into polar bear distribution, terrestrial habitat use, denning, and foraging patterns. Participants were unanimous in their recognition of a warming climate and prolonged ice-free season in the area in recent years. However, communities differed in their observations on other issues, with latitudinal trends evident in observations of polar bear distribution, denning activity, and foraging habits. Communities also differed in their perception of the prevalence of problem polar bears and the conservation status of the species, with one-third of participants reporting that polar bears will be unaffected by, or even benefit from, longer ice-free periods. A majority of participants indicated that the local polar bear population was stable or increasing. Interviewees also identified future research priorities pertinent to the communities, and provided comments on the methods employed by polar bear biologists. Our results demonstrate that communities in the EMR have important knowledge about polar bear ecology and illustrate the unique opportunities and challenges of combining traditional ecological knowledge with wildlife science in the context of a rapidly changing subarctic environment.L’ours blanc revêt un caractère socioculturel important pour les communautés de la Région marine d’Eeyou (RME), située dans le nord-ouest de la province de Québec, au Canada. Bien que les Cris de ces communautés ne soient pas reconnus pour chasser particulièrement l’ours blanc, ils partagent le territoire avec l’ours blanc lors de leurs déplacements et activités de chasse, de pêche et de trappe. Un nombre croissant de preuves scientifiques suggère que la réduction annuelle de la couverture de glace dans la baie d’Hudson aurait causé une dégradation de la condition physique des ours blancs de la sous-population sud de la baie d’Hudson et un déclin de la sous-population voisine, dans l’ouest de la baie d’Hudson. En juin 2012, nous avons réalisé une série de 15 entrevues semi-dirigées concernant la biologie de l’ours blanc et les changements climatiques avec des aînés et des chasseurs de trois communautés de la portion nordique de la RME : Wemindji, Chisasibi et Whapmagoostui. Les entrevues tenues à Whapmagoostui ont inclus des répondants du village inuit adjacent, Kuujjuarapik. Les entrevues abordaient des lacunes au niveau des connaissances, telles que déterminées par le Programme de rétablissement de l’ours polaire en Ontario. Les entrevues ont été transcrites et codées par thèmes afin d’être analysées suivant des méthodes qualitatives et quantitatives. Les entrevues révèlent d’importantes informations relativement aux connaissances sur la distribution, l’utilisation des habitats terrestres, les aires de mise bas et les habitudes alimentaires des ours blancs. Les participants ont unanimement constaté le réchauffement du climat et la prolongation de la période libre de glace au cours des dernières années sur leur territoire d’activités. Cependant, les points de vue des participants diffèrent pour ce qui est de certains enjeux, selon un gradient latitudinal évident, concernant la distribution, les activités de mise bas et les habitudes alimentaires de l’espèce. Les perceptions des communautés diffèrent aussi relativement à la prévalence des ours blancs problématiques et en ce qui concerne le statut de conservation de l’espèce, avec le tiers des participants jugeant que les ours blancs ne seraient pas affectés, ou pourraient même bénéficier, d’une plus longue période libre de glace. Une majorité de participants indique que la population locale d’ours blancs est stable ou en augmentation. Enfin, les répondants ont indiqué les priorités de recherches pertinentes à leur communauté et partagé des commentaires sur les méthodes employées par les biologistes. Les résultats montrent que les communautés de la RME possèdent des connaissances importantes concernant l’écologie de l’ours blanc, illustrant ainsi les opportunités et les défis afin de combiner ces données à celles des sciences biologiques, ceci dans un contexte de changement rapide de l’environnement subarctique
Polar bear depredation of a thick-billed murre fledgling in open water at Prince Leopold Island, Nunavut
Sea-ice distribution and duration are declining across the circumpolar range of the polar bear (Ursus maritimus), resulting in a reduced access to ice-obligate seals, its primary prey. Consequently, polar bears may have increased reliance on alternative food sources in the future. Foraging on land is well documented but foraging in open water is less understood. We report the successful depredation of a thick-billed murre (Uria lomvia) in open water near Prince Leopold Island, Nunavut, and discuss implications for understanding the behavioural plasticity of polar bears and their opportunistic foraging patterns.
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Re-assessing abundance of Southern Hudson Bay polar bears by aerial survey: effects of climate change at the southern edge of the range
The Southern Hudson Bay polar bear (Ursus maritimus Phipps, 1774) subpopulation is considered stable but conflicting evidence lends uncertainty to that designation. Capture-recapture studies conducted 1984-86 and 2003-05 and an aerial survey conducted 2011/12 suggested abundance was likely unchanged since the mid-1980s. However, body condition and body size declined since then, and duration of sea ice decreased by about 30 days. Due to conflicting information on subpopulation status and ongoing changes in sea ice, we conducted another aerial survey in 2016 to determine whether abundance had changed. We collected data via mark-recapture distance sampling and double-observer protocols. Results suggest abundance declined 17% from 943 bears (95% CI 658-1350) in 2011/12 to 780 (95% CI 590â 1029) in 2016. The proportion of yearlings declined from 12% of the population in 2011 to 5% in 2016, whereas the proportion of cubs remained similar (16% in 2011 vs. 19% in 2016) suggesting low survival of the 2015 cohort. In a warming Arctic, duration of sea ice is predicted to continue to decline in Hudson Bay affecting all ice-dependent wildlife; therefore, further monitoring of this subpopulation is warranted. We recommend a conservative approach to harvest management and repeating the aerial survey in 2021.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Comparison of methanol and isopropanol as wash solvents for determination of hair cortisol concentration in grizzly bears and polar bears
Methodological differences among laboratories are recognized as significant sources of variation in quantification of hair cortisol concentration (HCC). An important step in processing hair, particularly when collected from wildlife, is the choice of solvent used to remove or “wash” external hair shaft cortisol prior to quantification of HCC. The present study systematically compared methanol and isopropanol as wash solvents for their efficiency at removing external cortisol without extracting internal hair shaft cortisol in samples collected from free-ranging grizzly bears and polar bears. Cortisol concentrations in solvents and hair were determined in each of one to eight washes of hair with each solvent independently.
• There were no significant decreases in internal hair shaft cortisol among all eight washes for either solvent, although methanol removed detectable hair surface cortisol after one wash in grizzly bear hair whereas hair surface cortisol was detected in all eight isopropanol washes.
• There were no significant differences in polar bear HCC washed one to eight times with either solvent, but grizzly bear HCC was significantly greater in hair washed with isopropanol compared to methanol.
• There were significant differences in HCC quantified using different commercial ELISA kits commonly used for HCC determinations
Determining causes of genetic isolation in a large carnivore (Ursus americanus) population to direct contemporary conservation measures.
The processes leading to genetic isolation influence a population's local extinction risk, and should thus be identified before conservation actions are implemented. Natural or human-induced circumstances can result in historical or contemporary barriers to gene flow and/or demographic bottlenecks. Distinguishing between these hypotheses can be achieved by comparing genetic diversity and differentiation in isolated vs. continuous neighboring populations. In Ontario, American black bears (Ursus americanus) are continuously distributed, genetically diverse, and exhibit an isolation-by-distance structuring pattern, except on the Bruce Peninsula (BP). To identify the processes that led to the genetic isolation of BP black bears, we modelled various levels of historical and contemporary migration and population size reductions using forward simulations. We compared simulation results with empirical genetic indices from Ontario black bear populations under different levels of geographic isolation, and conducted additional simulations to determine if translocations could help achieve genetic restoration. From a genetic standpoint, conservation concerns for BP black bears are warranted because our results show that: i) a recent demographic bottleneck associated with recently reduced migration best explains the low genetic diversity on the BP; and ii) under sustained isolation, BP black bears could lose between 70% and 80% of their rare alleles within 100 years. Although restoring migration corridors would be the most effective method to enhance long-term genetic diversity and prevent inbreeding, it is unrealistic to expect connectivity to be re-established. Current levels of genetic diversity could be maintained by successfully translocating 10 bears onto the peninsula every 5 years. Such regular translocations may be more practical than landscape restoration, because areas connecting the peninsula to nearby mainland black bear populations have been irreversibly modified by humans, and form strong barriers to movement
Does Predation Influence the Seasonal and Diel Timing of Moose Calving in Central Ontario, Canada?
<div><p>Birth synchrony is well documented among ungulates and is hypothesised to maximize neonate survival, either by minimizing the risk of predation through predator swamping or by synchronising birthing with increased seasonal food availability. We used encapsulated vaginal implant transmitters to locate and capture neonatal moose calves and document the seasonal and diel timing of parturition in two adjacent study areas with different predation pressure in central Ontario, Canada. We tested the hypothesis that predation promotes earlier and more synchronous birth of moose calves. Across both areas, proportionately more births occurred during the afternoon and fewer than expected occurred overnight. Mean date of calving averaged 1.5 days earlier and calving was also more synchronous in the study area with heavier predation pressure, despite average green-up date and peak Normalized Difference Vegetation Index date occurring 2 days later in this study area than in the area receiving lighter predation pressure. We encourage analysis of data on timing of parturition from additional study areas experiencing varying degrees of predation pressure to better clarify the influence of predation in driving seasonal and diel timing of parturition in temperate ungulates.</p></div
Number of parturition events of radio-collared female moose in Algonquin Provincial Park (APP) and Wildlife Management Unit 49 (WMU49), central Ontario, Canada, for which day of parturition was precisely known 2006–08.
<p>Number of parturition events of radio-collared female moose in Algonquin Provincial Park (APP) and Wildlife Management Unit 49 (WMU49), central Ontario, Canada, for which day of parturition was precisely known 2006–08.</p
Location of study sites in Algonquin Provincial Park (APP) and Wildlife Management Unit 49 (WMU49) in central Ontario, Canada.
<p>The 2 study sites are hatched. </p