The bioclimatic envelope of the wolverine (Gulo gulo): do climatic constraints limit its geographic distribution?

Canadian Journal of Zoology (Impact Factor: 1.35). 02/2010; 88(3):233-246.

ABSTRACT 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 cover. Ninety-five percent of summer and 86% of winter telemetry locations were concordant with spring snow coverage. Average maximum August temperature was a less effective predictor of wolverine presence, although wolverines preferred summer temperatures lower than those available. Reductions in spring snow cover associated with climatic warming will likely reduce the extent of wolverine habitat, with an associated loss of connectivity.Nous présentons une répartition géographique fondamentale du glouton (Gulo gulo (L., 1758)) basée sur l'hypothèse selon laquelle la présence des gloutons est restreinte par leur association obligatoire à une couverture persistante de neige au printemps nécessaire pour le succès des terriers de reproduction, ainsi que par la limite supérieure de la thermoneutralité. Afin d'examiner cette hypothèse, nous mettons au point un assemblage d'images satellites classifiées MODIS représentant la couverture persistante de neige du 24 avril au 15 mai, ce qui englobe la fin de la période d'utilisation des terriers de reproduction chez les gloutons. Afin d'examiner la relation spatiale du glouton avec les températures maximales moyennes d'août, nous utilisons des cartes de températures interpolées. Ensuite, nous comparons et corrélons ces facteurs climatiques avec des données géographiques spatiales sur les emplacements des terriers de gloutons et les sites de télémétrie en Amérique du Nord et en Fennoscandie, ainsi qu'avec notre compréhension actuelle de l'aire de répartition circumboréale du glouton. Tous les 562 terriers de reproduction de Fennoscandie et d'Amérique du Nord se retrouvent dans des sites à couverture de neige persistante au printemps. Quatre-vingt-quinze pourcent des sites de télémétrie en été et 86 % des sites en hiver concordent avec la couverture de neige du printemps. La température maximale moyenne en août est une variable prédictive moins efficace de la présence des gloutons, bien que les gloutons préfèrent des températures d'été plus fraîches que celles qui sont disponibles. La réduction de la couverture de neige au printemps associée au réchauffement climatique va vraisemblablement réduire l'étendue de l'habitat du glouton, ce qui entraînera une perte de connectivité.

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    • "The raster habitat layer for wolverine describes areas with and without persistent spring snow (Copeland et al. 2010). To reduce computation time, we have reduced the study landscape to the Bitterroot Mountain Range along the Montana/Idaho border. "
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    ABSTRACT: 1.Power analysis is an important step in designing effective monitoring programs to detect trends in plant or animal populations. Although project goals often focus on detecting changes in population abundance, logistical constraints may require data collection on population indices, such as detection/non-detection data for occupancy estimation.2.We describe the open-source R package, rSPACE, for implementing a spatially-based power analysis for designing monitoring programs. This method incorporates information on species biology and habitat to parameterize a spatially-explicit population simulation. A sampling design can then be implemented to create replicate encounter histories which are subsampled and analyzed to estimate the power of the monitoring program to detect changes in population abundance over time, using occupancy as a surrogate.3.The proposed method and software are demonstrated with an analysis of wolverine monitoring in the U.S. Northern Rocky Mountain landscape.4.The package will be of use to ecologists interested in evaluating objectives and performance of monitoring programs.This article is protected by copyright. All rights reserved.
    Methods in Ecology and Evolution 03/2015; 6(5). DOI:10.1111/2041-210X.12369 · 5.32 Impact Factor
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    • "Wolverines were recently designated a candidate for listing in the contiguous US under the US Endangered Species Act (US Fish and Wildlife Service, 2010; US Fish and Wildlife Service, 2013). Wolverine habitat in the contiguous US appears to consist of disjunct patches of mountainous, high alpine areas inhabited at low densities and requiring dispersal across intervening areas (Copeland et al., 2010; Inman et al., 2012a), likely a prime example of a metapopulation (Hanski and Gaggiotti, 2004). The metapopulation concept has evolved from island biogeographic theory (Mac- Arthur and Wilson, 1967) into complex estimates of population viability that are based on the spatial arrangement of habitat patches, habitat quality within and between patches, demographic rates, and dispersal (Akçakaya and Atwood, 1997; Haines et al., 2006). "
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    ABSTRACT: Wildlife populations are often influenced by multiple political jurisdictions. This is particularly true for wide-ranging, low-density carnivores whose populations have often contracted and remain threatened, heightening the need for geographically coordinated priorities at the landscape scale. Yet even as modern policies facilitate species recoveries, gaps in knowledge of historical distributions, population capacities, and potential for genetic exchange inhibit development of population-level conservation priorities. Wolverines are an 8-18 kg terrestrial weasel (Mustelidae) that naturally exist at low densities (∼5/1000 km2) in cold, often snow-covered areas. Wolverines were extirpated, or nearly so, from the contiguous United States by 1930. We used a resource selection function to (1) predict habitat suitable for survival, reproduction and dispersal of wolverines across the western US, (2) make a rough estimate of population capacity, and (3) develop conservation priorities at the metapopulation scale. Primary wolverine habitat (survival) existed in island-like fashion across the western US, and we estimated capacity to be 644 wolverines (95% CI = 506-1881). We estimated current population size to be approximately half of capacity. Areas we predicted suitable for male dispersal linked all patches, but some potential core areas appear to be relatively isolated for females. Reintroduction of wolverines to the Southern Rockies and Sierra-Nevadas has the potential to increase population size by >50% and these regions may be robust to climate change. The Central Linkage Region is an area of great importance for metapopulation function, thus warranting collaborative strategies for maintaining high survival rates, high reproductive rates, and dispersal capabilities. Our analysis can help identify dispersal corridors, release locations for reintroductions, and monitoring targets. The process we used can serve as an example for developing collaborative, landscape-scale, conservation priorities for data-sparse metapopulations.
    Biological Conservation 10/2013; 166:276-286. DOI:10.1016/j.biocon.2013.07.010 · 4.04 Impact Factor
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    • "In this area, wolverines might be more dependent on carrion, wolf-killed moose (Alces alces), and self-hunted smaller prey, such as mountain hares (Lepus timidus), grouse and small rodents, as observed in southern Norway (van Dijk et al. 2008b). The wolverine is a terrestrial mustelid that has a circumpolar distribution corresponding with the arctic and subarctic regions and also boreal forests of Eurasia and North America (Landa et al. 2000, Copeland et al. 2010). Urban development, human disturbance and persecution have contributed to the currently restricted distribution of the wolverine (Banci 1994, Copeland 1996, Carroll et al. 2001, Persson et al. 2009). "
    Annales Zoologici Fennici 08/2013; 50:216-224. DOI:10.5735/085.050.0405 · 1.03 Impact Factor
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