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Arild Landa - One of the best experts on this subject based on the ideXlab platform.
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the bioclimatic envelope of the wolverine Gulo Gulo do climatic constraints limit its geographic distribution
Canadian Journal of Zoology, 2010Co-Authors: Jeffrey P Copeland, Arild Landa, Eric C Lofroth, Keith B. Aubry, Kevin S Mckelvey, Jens Persson, Robert M Inman, John R Krebs, Howard N Golden, John R SquiresAbstract:We propose a fundamental geographic distribution for the wolverine (Gulo Gulo (L., 1758)) based on the hypothesis that the occurrence of wolverines is constrained by their obligate association with persistent spring snow cover for successful reproductive denning and by an upper limit of thermoneutrality. To investigate this hypothesis, we developed a composite of MODIS classified satellite images representing persistent snow cover from 24 April to 15 May, which encompasses the end of the wolverine’s reproductive denning period. To investigate the wolverine’s spatial relationship with average maximum August temperatures, we used interpolated temperature maps. We then compared and correlated these climatic factors with spatially referenced data on wolverine den sites and telemetry locations from North America and Fennoscandia, and our contemporary understanding of the wolverine’s circumboreal range. All 562 reproductive dens from Fennoscandia and North America occurred at sites with persistent spring snow c...
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the bioclimatic envelope of the wolverine Gulo Gulo do climatic constraints limit its geographic distribution
Canadian Journal of Zoology, 2010Co-Authors: Jeffrey P Copeland, Arild Landa, Eric C Lofroth, Keith B. Aubry, Kevin S Mckelvey, Jens Persson, Robert M Inman, John R Krebs, Howard N Golden, John R SquiresAbstract:We propose a fundamental geographic distribution for the wolverine (Gulo Gulo (L., 1758)) based on the hypothesis that the occurrence of wolverines is constrained by their obligate association with...
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evaluating scat analysis methods to assess wolverine Gulo Gulo diet
Wildlife Biology, 2007Co-Authors: Jiska Joanneke Van Dijk, Arild Landa, Roy Andersen, Kjetil Hauge, Roel MayAbstract:Abstract A feeding trial was carried out on two captive wolverines Gulo Gulo to evaluate methods to assess wolverine diets through scat content. During the feeding trial, wolverines were offered known quantities of five prey species. All scats were collected and their contents analysed. We evaluated four widely used methods of quantifying dietary composition: dry weight, index of relative contribution, frequency of occurrence, and percentage of occurrence. Based on the outcome of this evaluation, percentage of occurrence was found to be the most appropriate method for wolverine diet studies given the extreme variation in prey items (e.g. prey type and age) and undigested items (e.g. hide and bones) in the wolverine's diet. Dry weight may provide additional information on the amount of biomass consumed, which is biologically more meaningful than just the composition assessment derived from using the percentage of occurrence.
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paternity and mating system in wolverines Gulo Gulo
Wildlife Biology, 2007Co-Authors: Eva Hedmark, Arild Landa, Peter Segerstrom, Jens Persson, Hans EllegrenAbstract:Knowledge of the wolverine Gulo Gulo mating system is limited. In this study, we use 20 microsatellite loci for paternity testing in 145 wolverine offspring with known mothers. Samples were collected during > 10 years in two Scandinavian populations, mainly in connection with radio-telemetry studies and as part of long-term population monitoring. In total, 51% of the offspring were assigned a father. Our results demonstrate that the wolverine exhibits a polygamous mating system as some males were shown to produce offspring with more than one female in a single year. Females often reproduced with the same male in subsequent breeding years, but sometimes changed their partner, potentially as a consequence of a change in the territory-holding male in the area. In the majority of litters, siblings were unambiguously assigned the same father, indicating that multiple paternity is rare. Of 23 breeding pairs, for which telemetry data were available, 20 had overlapping home ranges, suggesting that pair formation generally is consistent with the territories held by wolverine males and females.
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impact of infrastructure on habitat selection of wolverines Gulo Gulo
Wildlife Biology, 2006Co-Authors: Roel May, Arild Landa, John D C Linnell, Jiska Joanneke Van Dijk, Roy AndersenAbstract:Abstract Compared to the other northern large carnivores, wolverines Gulo Gulo are thought to be the most sensitive species with regard to habitat changes and human disturbance. Nowadays wolverines in Scandinavia are found in remote high alpine areas, and we investigated whether human development through presence of infrastructure has relegated them to these areas. We analysed wolverine habitat selection and the impact of infrastructure in two study areas in Norway using compositional analysis. We found that alpine tundra with low human development was important for wolverines to locate their home ranges. Human development formed a more important factor for home range location than did habitat, because habitat selectivity was much higher in undeveloped habitats than in developed habitats. Within their home ranges, wolverines used alpine shrubland and forest, irrespective of human development. The sympatric distribution of wolverines with wild and semi-domestic reindeer Rangifer tarandus indicates that wol...
Jens Persson - One of the best experts on this subject based on the ideXlab platform.
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Sample identification and pedigree reconstruction in Wolverine (Gulo Gulo) using SNP genotyping of non-invasive samples
Conservation Genetics Resources, 2021Co-Authors: Robert Ekblom, Malin Aronsson, Franziska Elsner-gearing, Malin Johansson, Toby Fountain, Jens PerssonAbstract:For conservation genetic studies using non-invasively collected samples, genome-wide data may be hard to acquire. Until now, such studies have instead mostly relied on analyses of traditional genetic markers such as microsatellites (SSRs). Recently, high throughput genotyping of single nucleotide polymorphisms (SNPs) has become available, expanding the use of genomic methods to include non-model species of conservation concern. We have developed a 96-marker SNP array for use in applied conservation monitoring of the Scandinavian wolverine ( Gulo Gulo ) population. By genotyping more than a thousand non-invasively collected samples, we were able to obtain precise estimates of different types of genotyping errors and sample dropout rates. The SNP panel significantly outperforms the SSR markers (and DBY intron markers for sexing) both in terms of precision in genotyping, sex assignment and individual identification, as well as in the proportion of samples successfully genotyped. Furthermore, SNP genotyping offers a simplified laboratory and analysis pipeline with fewer samples needed to be repeatedly genotyped in order to obtain reliable consensus data. In addition, we utilised a unique opportunity to successfully demonstrate the application of SNP genotype data for reconstructing pedigrees in wild populations, by validating the method with samples from wild individuals with known relatedness. By offering a simplified workflow with improved performance, we anticipate this methodology will facilitate the use of non-invasive samples to improve genetic management of many different types of populations that have previously been challenging to survey.
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Refrigeration or anti-theft? Food-caching behavior of Wolverines (Gulo Gulo) in Scandinavia
Behavioral Ecology and Sociobiology, 2020Co-Authors: Bert Van Der Veen, Jenny Mattisson, Barbara Zimmermann, John Odden, Jens PerssonAbstract:Food-caching animals can gain nutritional advantages by buffering seasonality in food availability, especially during times of scarcity. The wolverine (Gulo Gulo) is a facultative predator that occupies environments of low productivity. As an adaptation to fluctuating food availability, wolverines cache perishable food in snow, boulders, and bogs for short- and long-term storage. We studied caching behavior of 38 GPS-collared wolverines in four study areas in Scandinavia. By investigating clusters of GPS locations, we identified a total of 303 food caches from 17 male and 21 female wolverines. Wolverines cached food all year around, from both scavenging and predation events, and spaced their caches widely within their home range. Wolverines cached food items on average 1.1 km from the food source and made between 1 and 6 caches per source. Wolverines cached closer to the source when scavenging carcasses killed by other large carnivores; this might be a strategy to optimize food gain when under pressure of interspecific competition. When caching, wolverines selected for steep and rugged terrain in unproductive habitat types or in forest, indicating a preference for less-exposed sites that can provide cold storage and/or protection against pilferage. The observed year-round investment in caching by wolverines underlines the importance of food predictability for survival and reproductive success in this species. Increasing temperatures as a consequence of climate change may provide new challenges for wolverines by negatively affecting the preservation of cached food and by increasing competition from pilferers that benefit from a warmer climate. It is however still not fully understood which consequences this may have for the demography and behavior of the wolverine. Food caching is a behavioral strategy used by a wide range of animals to store food for future use. Choosing appropriate caching sites appears important for slowing down decomposition rates and minimizes competition. In this study, we demonstrate that the wolverine, an opportunistic predator and scavenger, utilizes available carrion to create caches all year around. By following wolverines with GPS collars, we registered that they carried food far away to cache it in secluded and cold places, which are often located on steep slopes or in forest. However, when scavenging other carnivores’ prey, they move food in shorter distances, possibly to be able to quickly return for more. The observed efficiency in wolverine caching behavior is likely vital for their survival and reproductive success in the harsh and highly seasonal environment in which they live.
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Paying for an Endangered Predator Leads to Population Recovery
Conservation Letters, 2015Co-Authors: Jens Persson, Geir Rune Rauset, Guillaume ChapronAbstract:Keeping viable predator populations on a human-dominated planet will require innovative approaches that promote local coexistence with human activities. Conservation performance payments, which are linked specifically to the production of a desired environmental output, have received increasing attention but their effectiveness in predator conservation remains undocumented. Here, we show that paying Sami reindeer herders for wolverine (Gulo Gulo) reproductions has been instrumental in the recovery of wolverines in Sweden. Adult female wolverines were significantly less exposed to illegal killing and this allowed the population to more than double in a decade. We argue that this program provides protection for adult female wolverines through a combination of direct monetary value and indirect protection because of monitoring activities. The program's success, even in a system where livestock is the main prey for the predator, reveals an exceptional potential for future implementations in large carnivore conservation.
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the bioclimatic envelope of the wolverine Gulo Gulo do climatic constraints limit its geographic distribution
Canadian Journal of Zoology, 2010Co-Authors: Jeffrey P Copeland, Arild Landa, Eric C Lofroth, Keith B. Aubry, Kevin S Mckelvey, Jens Persson, Robert M Inman, John R Krebs, Howard N Golden, John R SquiresAbstract:We propose a fundamental geographic distribution for the wolverine (Gulo Gulo (L., 1758)) based on the hypothesis that the occurrence of wolverines is constrained by their obligate association with persistent spring snow cover for successful reproductive denning and by an upper limit of thermoneutrality. To investigate this hypothesis, we developed a composite of MODIS classified satellite images representing persistent snow cover from 24 April to 15 May, which encompasses the end of the wolverine’s reproductive denning period. To investigate the wolverine’s spatial relationship with average maximum August temperatures, we used interpolated temperature maps. We then compared and correlated these climatic factors with spatially referenced data on wolverine den sites and telemetry locations from North America and Fennoscandia, and our contemporary understanding of the wolverine’s circumboreal range. All 562 reproductive dens from Fennoscandia and North America occurred at sites with persistent spring snow c...
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the bioclimatic envelope of the wolverine Gulo Gulo do climatic constraints limit its geographic distribution
Canadian Journal of Zoology, 2010Co-Authors: Jeffrey P Copeland, Arild Landa, Eric C Lofroth, Keith B. Aubry, Kevin S Mckelvey, Jens Persson, Robert M Inman, John R Krebs, Howard N Golden, John R SquiresAbstract:We propose a fundamental geographic distribution for the wolverine (Gulo Gulo (L., 1758)) based on the hypothesis that the occurrence of wolverines is constrained by their obligate association with...
Shit F Chew - One of the best experts on this subject based on the ideXlab platform.
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l Gulono γ lactone oxidase expression and vitamin c synthesis in the brain and kidney of the african lungfish protopterus annectens
The FASEB Journal, 2014Co-Authors: Biyun Ching, You Rong Chng, Xiu Ling Chen, Shit F Chew, Wai P Wong, Yuen K IpAbstract:This study aimed to test the hypothesis that the brain of Protopterus annectens expressed l-Gulono-γ-lactone oxidase (Gulo/Gulo), the enzyme catalyzing the last step of ascorbate biosynthesis, and could maintain high concentrations of ascorbate during estivation. We cloned and sequenced Gulo from the kidney of P. annectens and performed quantitative PCR to determine its mRNA expression in kidney and brain. Gulo activity was assayed and its protein abundance was determined by Western blot using custom-made anti-Gulo antibody. Effects of estivation on concentrations of ascorbate and dehydroascorbate in the kidney and brain were also determined. Both brain and kidney, but not liver, of P. annectens expressed Gulo/Gulo. Desiccation induced P. annectens to estivate, and 6 mo of estivation led to drastic decreases in Gulo/Gulo expression and ascorbate concentration in the kidney. However, high concentrations of ascorbate and ascorbate + dehydroascorbate were maintained in the brain during estivation, probably r...
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l Gulono γ lactone oxidase expression and vitamin c synthesis in the brain and kidney of the african lungfish protopterus annectens
The FASEB Journal, 2014Co-Authors: Biyun Ching, You Rong Chng, Xiu Ling Chen, Wai P Wong, Jasmine L Y Ong, Shit F ChewAbstract:This study aimed to test the hypothesis that the brain of Protopterus annectens expressed L-Gulono-γ-lactone oxidase (Gulo/Gulo), the enzyme catalyzing the last step of ascorbate biosynthesis, and could maintain high concentrations of ascorbate during estivation. We cloned and sequenced Gulo from the kidney of P. annectens and performed quantitative PCR to determine its mRNA expression in kidney and brain. Gulo activity was assayed and its protein abundance was determined by Western blot using custom-made anti-Gulo antibody. Effects of estivation on concentrations of ascorbate and dehydroascorbate in the kidney and brain were also determined. Both brain and kidney, but not liver, of P. annectens expressed Gulo/Gulo. Desiccation induced P. annectens to estivate, and 6 mo of estivation led to drastic decreases in Gulo/Gulo expression and ascorbate concentration in the kidney. However, high concentrations of ascorbate and ascorbate + dehydroascorbate were maintained in the brain during estivation, probably resulting from in situ ascorbate synthesis. Control fish were placed in freshwater, where they were fully active in a favorable environment unlike estivation on land. The ability to synthesize ascorbate to ameliorate oxidative stress directly in the brain might contribute to the ability of P. annectens to undergo prolonged estivation on land.
Biyun Ching - One of the best experts on this subject based on the ideXlab platform.
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l Gulono γ lactone oxidase expression and vitamin c synthesis in the brain and kidney of the african lungfish protopterus annectens
The FASEB Journal, 2014Co-Authors: Biyun Ching, You Rong Chng, Xiu Ling Chen, Shit F Chew, Wai P Wong, Yuen K IpAbstract:This study aimed to test the hypothesis that the brain of Protopterus annectens expressed l-Gulono-γ-lactone oxidase (Gulo/Gulo), the enzyme catalyzing the last step of ascorbate biosynthesis, and could maintain high concentrations of ascorbate during estivation. We cloned and sequenced Gulo from the kidney of P. annectens and performed quantitative PCR to determine its mRNA expression in kidney and brain. Gulo activity was assayed and its protein abundance was determined by Western blot using custom-made anti-Gulo antibody. Effects of estivation on concentrations of ascorbate and dehydroascorbate in the kidney and brain were also determined. Both brain and kidney, but not liver, of P. annectens expressed Gulo/Gulo. Desiccation induced P. annectens to estivate, and 6 mo of estivation led to drastic decreases in Gulo/Gulo expression and ascorbate concentration in the kidney. However, high concentrations of ascorbate and ascorbate + dehydroascorbate were maintained in the brain during estivation, probably r...
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l Gulono γ lactone oxidase expression and vitamin c synthesis in the brain and kidney of the african lungfish protopterus annectens
The FASEB Journal, 2014Co-Authors: Biyun Ching, You Rong Chng, Xiu Ling Chen, Wai P Wong, Jasmine L Y Ong, Shit F ChewAbstract:This study aimed to test the hypothesis that the brain of Protopterus annectens expressed L-Gulono-γ-lactone oxidase (Gulo/Gulo), the enzyme catalyzing the last step of ascorbate biosynthesis, and could maintain high concentrations of ascorbate during estivation. We cloned and sequenced Gulo from the kidney of P. annectens and performed quantitative PCR to determine its mRNA expression in kidney and brain. Gulo activity was assayed and its protein abundance was determined by Western blot using custom-made anti-Gulo antibody. Effects of estivation on concentrations of ascorbate and dehydroascorbate in the kidney and brain were also determined. Both brain and kidney, but not liver, of P. annectens expressed Gulo/Gulo. Desiccation induced P. annectens to estivate, and 6 mo of estivation led to drastic decreases in Gulo/Gulo expression and ascorbate concentration in the kidney. However, high concentrations of ascorbate and ascorbate + dehydroascorbate were maintained in the brain during estivation, probably resulting from in situ ascorbate synthesis. Control fish were placed in freshwater, where they were fully active in a favorable environment unlike estivation on land. The ability to synthesize ascorbate to ameliorate oxidative stress directly in the brain might contribute to the ability of P. annectens to undergo prolonged estivation on land.
Thomas S. Jung - One of the best experts on this subject based on the ideXlab platform.
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dynamic landscapes in northwestern north america structured populations of wolverines Gulo Gulo
Journal of Mammalogy, 2021Co-Authors: Dianna M Krejsa, Audrey J Magoun, Thomas S. Jung, Sandra L Talbot, George K Sage, Sarah A Sonsthagen, Joseph A CookAbstract:Cyclic climatic and glacial fluctuations of the Late Quaternary produced a dynamic biogeographic history for high latitudes. To refine our understanding of this history in northwestern North America, we explored geographic structure in a wide-ranging carnivore, the wolverine (Gulo Gulo). We examined genetic variation in populations across mainland Alaska, coastal Southeast Alaska, and mainland western Canada using nuclear microsatellite genotypes and sequence data from the mitochondrial DNA (mtDNA) control region and Cytochrome b (Cytb) gene. Data from maternally inherited mtDNA reflect stable populations in Northwest Alaska, suggesting the region harbored wolverine populations since at least the Last Glacial Maximum (LGM; 21 Kya), consistent with their persistence in the fossil record of Beringia. Populations in Southeast Alaska are characterized by minimal divergence, with no genetic signature of long-term refugial persistence (consistent with the lack of pre-Holocene fossil records there). The Kenai Peninsula population exhibits mixed signatures depending on marker type: mtDNA data indicate stability (i.e., historical persistence) and include a private haplotype, whereas biparentally inherited microsatellites exhibit relatively low variation and a lack of private alleles consistent with a more recent Holocene colonization of the peninsula. Our genetic work is largely consistent with the early 20th century taxonomic hypothesis that wolverines on the Kenai Peninsula belong to a distinct subspecies. Our finding of significant genetic differentiation of wolverines inhabiting the Kenai Peninsula, coupled with the peninsula's burgeoning human population and the wolverine's known sensitivity to anthropogenic impacts, provides valuable foundational data that can be used to inform conservation and management prescriptions for wolverines inhabiting these landscapes.
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high prevalence intensity and genetic diversity of trichinella spp in wolverine Gulo Gulo from yukon canada
Parasites & Vectors, 2021Co-Authors: Rajnish Sharma, Thomas S. Jung, Piia M. Kukka, Jane N Harms, Sarah Parker, Sasha Ross, Peter C Thompson, Benjamin M Rosenthal, Eric P HobergAbstract:Species of Trichinella are globally important foodborne parasites infecting a number of domestic and wild vertebrates, including humans. Free-ranging carnivores can act as sentinel species for detection of Trichinella spp. Knowledge of the epidemiology of these parasites may help prevent Trichinella spp. infections in northern Canadian animals and people. Previous research on Trichinella spp. in wildlife from Yukon did not identify risk factors associated with infection, or the diversity and identity of species of Trichinella in regional circulation, based on geographically extensive sampling with large sample sizes. In a cross-sectional study, we determined the prevalence, infection intensity, risk factors, and species or genotypes of Trichinella in wolverine (Gulo Gulo) in two regions of Yukon, Canada, from 2013–2017. A double separatory funnel digestion method followed by mutiplex PCR and PCR-RFLP were used to recover and identify species of Trichinella, respectively. We found larvae of Trichinella in the tongues of 78% (95% CI 73–82) of 338 wolverine sampled. The odds of adult (≥ 2 years) and yearling (1 year) wolverine being Trichinella spp.-positive were four and two times higher, respectively, compared to juveniles (<1 year). The odds of Trichinella spp. presence were three times higher in wolverine from southeast than northwest Yukon. The mean intensity of infection was 22.6 ± 39 (SD, range 0.1–295) larvae per gram. Trichinella T6 was the predominant genotype (76%), followed by T. nativa (8%); mixed infections with Trichinella T6 and T. nativa (12%) were observed. In addition, T. spiralis was detected in one wolverine. Out of 22 isolates initially identified as T. nativa in multiplex PCR, 14 were analyzed by PCR-RFLP to distinguish them from T. chanchalensis, a recently discovered cryptic species, which cannot be distinguished from the T. nativa on multiplex PCR. Ten isolates were identified either as T. chanchalensis alone (n = 7), or mixed infection with T. chanchalensis and T. nativa (n = 2) or T. chanchalensis and Trichinella T6 (n = 1)]. Wolverine hosted high prevalence, high larval intensity, and multiple species of Trichinella, likely due to their scavenging habits, apex position in the food chain, and wide home range. Wolverine (especially adult males) should be considered as a sentinel species for surveys for Trichinella spp. across their distributional range.
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error in trapper reported sex of lynx lynx canadensis and wolverine Gulo Gulo implications for analyses of harvest records
European Journal of Wildlife Research, 2020Co-Authors: Thomas S. Jung, Piia M. Kukka, Fiona K A Schmiegelow, Michael J L Peers, Rudy Boonstra, Stan Boutin, Yasmine N MajchrzakAbstract:Monitoring trends in the abundance of furbearers may be challenging, particularly at the spatio-temporal scales relevant for management. As such, wildlife managers often rely on harvest records to identify broad-scale harvest patterns and trends. Yet, the reliability of harvest records is often unknown. Analyses of harvest records to determine quotas and assess sustainability need to account for error rates when they are > 0. We evaluated the accuracy of trapper-reported sex of lynx (Lynx canadensis; n = 185) and wolverine (Gulo Gulo; n = 467)—two meso-carnivores commonly targeted by fur trappers in northwestern Canada and Alaska—by comparing that to sex determined via necropsies of the same carcasses. Overall error rates differed significantly between wolverine (5%) and lynx (13%). Error rates were sex-biased for wolverine, but not lynx. Body size did not affect error rates for either species. Our data demonstrated species- and sex-specific error rates in the sex reported in harvest records. Error rates for wolverine (5%) were likely trivial for determining harvest sustainability because sex-based bias was small, given that overall accuracy was high. While error rates were greater for lynx (13%), there was no sex-based bias in trapper-reported sex. Because accuracy was lower for lynx, managers should exercise caution when using trapper-reported sex to conduct population analyses or assess harvest sustainability. Managers should be particularly interested in error rates of harvested species that exhibit relatively little sexual size dimorphism and lack obvious genitalia, similar to lynx. We recommend assessing error in trapper-reported sex prior to analysis of harvest records, as well as ongoing education with trappers to increase their ability to reliably determine the sex of animals they harvest.
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tongue has higher larval burden of trichinella spp than diaphragm in wolverines Gulo Gulo
Veterinary Parasitology, 2018Co-Authors: Rajnish Sharma, Thomas S. Jung, Piia M. Kukka, Jane N Harms, Sarah Parker, Alvin A Gajadhar, Emily J JenkinsAbstract:Abstract Trichinella is an important zoonotic parasite found in a range of wildlife species harvested for food and fur in Canada. We compared larval intensity from tongue and diaphragm, the best predilection sites in other animal species, from naturally infected, wild wolverines (Gulo Gulo) (n = 95). Muscle larvae of Trichinella spp. were recovered by the pepsin/HCl artificial digestion method (gold standard) using double separatory funnels, and species were identified using multiplex PCR. Prevalence was 83% (79/95). Of those positive for Trichinella spp. (n = 79), 76 (96.2%) were detected in both tissues, 2 (2.5%) were positive only on diaphragm, and 1 (1.3%) only on tongue. A total of 62 of 79 wolverines (78.5%) had higher larval burden in tongue than in diaphragm, whereas 17 wolverines (21.5%) had higher larval burden in diaphragm. The predilection site (higher larval burden) of Trichinella spp. larvae did not vary significantly between juvenile and adult wolverines (P = 0.2), between male and female wolverines (P = 0.9), and among wolverines classified as having low and high larval intensities overall (P = 0.2). Trichinella T6 was the predominant genotype (63 of 79; 80%), followed by T. nativa (T2) (6 of 79; 8%). Mixed infections of T2 and T6 were observed in 9 of 79 (12%) wolverines. Larval intensity of Trichinella T6 was higher in tongues than diaphragms. No statement can be made for T2 due to insufficient T2 positive samples. In conclusion, tongues are a better site for sampling than diaphragms in future surveys of Trichinella larval intensity in wolverines; however, either tissue is suitable for prevalence studies.
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temporal variation in the population characteristics of harvested wolverine Gulo Gulo in northwestern canada
Wildlife Research, 2017Co-Authors: Piia M. Kukka, Thomas S. Jung, Jean-françois Robitaille, Fiona K A SchmiegelowAbstract:Context Wolverines (Gulo Gulo) are harvested for fur in northern Canada; however, the impacts of harvest are poorly known. Additionally, wolverine population data are largely absent for much of their northern range. Demographic data collected from harvested wolverines provide information on the vulnerability and variability of different sex and age cohorts to harvest, which, in turn, may have implications for harvest sustainability. Aims We examined the temporal variability of different sex and age cohorts in wolverine harvest among years, and within the harvest season, in Yukon, Canada. We also examined the pregnancy status of female wolverines in relation to the harvest date, so as to evaluate the impact of the harvest-season length on breeding wolverines. Methods We determined the sex and age composition of harvested wolverines via dissections of 655 carcasses collected from 2005 to 2014. We determined the reproductive status and fetal measurements for female wolverines via dissections of reproductive tracts. Key results The harvest consisted mostly of males, particularly of young individuals. The sex ratio of harvested animals did not fluctuate significantly, but we observed variation in the age structure among years. The age structure varied within the harvest season (November to March), with a greater proportion of adults being harvested in late winter. Active gestation was evident in females harvested after mid-January, and near-term or postpartum females were harvested during late February and March. Conclusions Late winter harvest is likely to have a more significant impact on populations than is early winter harvest, because of increased harvest of adults and breeding females. Wolverine harvest season extends to the onset of the denning season in late February and March, indicating a concern for ethical harvest. Implications Limiting the legal harvest season to early winter may contribute to improved harvest sustainability and protection of breeding wolverines in northern latitudes.