Wildlife Research and Management

Fairbanks, AK, United States

Wildlife Research and Management

Fairbanks, AK, United States

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News Article | May 24, 2017
Site: www.rdmag.com

Will reductions in Arctic snow cover make tundra-dwelling wolverines more vulnerable to climate change than previously thought? That’s a question scientists hope an innovative method described in a new study co-authored by WCS (Wildlife Conservation Society) will help answer. Wolverines are the largest land-dwelling members of the weasel family, and use snow-pack for denning, caching food, and other needs. Since snow cover provides a key component to wolverine habitat, determining where snow will be available, and in what amounts, will be critical to managing the future for the elusive carnivores. That determination is seen as key to deciding listing under the Endangered Species Act. To better inform this discussion, the United States Fish and Wildlife Service has stated the need for more information on the relationship of wolverine distribution to persistent snow at the den-scale. In their study, the authors looked at snow at the den-site scale in late May using low-altitude aerial photography in wolverine denning habitat both in the Rocky Mountains of the western United States and in northwestern Alaska. In the Rocky Mountains, they documented snow in all but one study area. Snow in the Alaska study area was mostly gone, with only widely scattered patches remaining for cover.  The study emphasizes the need for additional surveys to determine whether reductions in Arctic snow cover could make tundra-dwelling wolverines more vulnerable to climate change than previously thought. Meanwhile, the WCS Arctic Beringia Program is focusing on how wolverines use that snow and how obligate this usage is—information vital to optimally managing this species in a time of rapid climatic change. Staff have just returned from three months of working on Alaska’s North Slope in frigid temperatures in an effort to identify areas used by wolverines and monitor them with remote cameras and GPS collars. This equipment will document how wolverines use the landscape from a time of 100 percent snow cover to bare tundra, allowing scientists to assess how animals use snow, their productivity, diet, and other key questions. “The question on how wolverines will be affected by climate change is clearly complex,” says WCS wolverine program coordinator and lead researcher Tom Glass. “During our aerial and ground-based surveys on the North Slope, we have observed the use of snow holes for denning, and also by both males and females for caching food, resting, or perhaps shelter from predators such as wolves.” If snow is lost too early, then wolverine kits may be exposed to the elements and predators before they are ready. Using both traditional scientific surveys as well as learning from local Iñupiat experts who have hunted and trapped wolverines (locally known as Qavvik) for generations, new information collected will help inform an assessment of the health of the population. Glass’s work over the next two years will focus on mapping habitat use in the spring as snow melts earlier and more variably in the Arctic. “Given the iconic recognition of wolverines, it is surprising how little we know about their ecology in the Arctic,” says Glass. To secure a future for wolverines, increasing that understanding is priority one. “Detecting Snow at the Den-Site Scale in Wolverine Denning Habitat,” appears currently in the Wildlife Society Bulletin. (https://doi.org/10.1002/wsb.765). Authors include: Audrey J. Magoun of Wildlife Research and Management; Mark L. Packila of Wildlife Air; and Tom W. Glass and Martin D. Robards of the Wildlife Conservation Society. This work was supported by the M.J. Murdock Charitable Trust, Wilburforce Foundation, and The Wolverine Foundation, Inc.


News Article | May 24, 2017
Site: www.eurekalert.org

Will reductions in Arctic snow cover make tundra-dwelling wolverines more vulnerable to climate change than previously thought? That's a question scientists hope an innovative method described in a new study co-authored by WCS (Wildlife Conservation Society) will help answer. Wolverines are the largest land-dwelling members of the weasel family, and use snow-pack for denning, caching food, and other needs. Since snow cover provides a key component to wolverine habitat, determining where snow will be available, and in what amounts, will be critical to managing the future for the elusive carnivores. That determination is seen as key to deciding listing under the Endangered Species Act. To better inform this discussion, the United States Fish and Wildlife Service has stated the need for more information on the relationship of wolverine distribution to persistent snow at the den-scale. In their study, the authors looked at snow at the den-site scale in late May using low-altitude aerial photography in wolverine denning habitat both in the Rocky Mountains of the western United States and in northwestern Alaska. In the Rocky Mountains, they documented snow in all but one study area. Snow in the Alaska study area was mostly gone, with only widely scattered patches remaining for cover. The study emphasizes the need for additional surveys to determine whether reductions in Arctic snow cover could make tundra-dwelling wolverines more vulnerable to climate change than previously thought. Meanwhile, the WCS Arctic Beringia Program is focusing on how wolverines use that snow and how obligate this usage is--information vital to optimally managing this species in a time of rapid climatic change. Staff have just returned from three months of working on Alaska's North Slope in frigid temperatures in an effort to identify areas used by wolverines and monitor them with remote cameras and GPS collars. This equipment will document how wolverines use the landscape from a time of 100 percent snow cover to bare tundra, allowing scientists to assess how animals use snow, their productivity, diet, and other key questions. "The question on how wolverines will be affected by climate change is clearly complex," says WCS wolverine program coordinator and lead researcher Tom Glass. "During our aerial and ground-based surveys on the North Slope, we have observed the use of snow holes for denning, and also by both males and females for caching food, resting, or perhaps shelter from predators such as wolves." If snow is lost too early, then wolverine kits may be exposed to the elements and predators before they are ready. Using both traditional scientific surveys as well as learning from local Iñupiat experts who have hunted and trapped wolverines (locally known as Qavvik) for generations, new information collected will help inform an assessment of the health of the population. Glass's work over the next two years will focus on mapping habitat use in the spring as snow melts earlier and more variably in the Arctic. "Given the iconic recognition of wolverines, it is surprising how little we know about their ecology in the Arctic," says Glass. To secure a future for wolverines, increasing that understanding is priority one. "Detecting Snow at the Den-Site Scale in Wolverine Denning Habitat," appears currently in the Wildlife Society Bulletin. Access full article at: (https:/ ). Authors include: Audrey J. Magoun of Wildlife Research and Management; Mark L. Packila of Wildlife Air; and Tom W. Glass and Martin D. Robards of the Wildlife Conservation Society. This work was supported by the M.J. Murdock Charitable Trust, Wilburforce Foundation, and The Wolverine Foundation, Inc. About the Wildlife Conservation Society. WCS saves wildlife and wild places worldwide through science, conservation action, education, and inspiring people to value nature. To achieve our mission, WCS, based at the Bronx Zoo, harnesses the power of its Global Conservation Program in nearly 60 nations and in all the world's oceans and its five wildlife parks in New York City, visited by 4 million people annually. WCS combines its expertise in the field, zoos, and aquarium to achieve its conservation mission. Visit: newsroom.wcs.org Follow: @WCSNewsroom. For more information: 347-840-1242.


McKelvey K.S.,Rocky Research | Lofroth E.C.,Environment Canada | Copeland J.P.,Rocky Research | Aubry K.B.,U.S. Department of Agriculture | Magoun A.J.,Wildlife Research and Management
Population Ecology | Year: 2011

The recent paper by Brodie and Post ("Nonlinear responses of wolverine populations to declining winter snowpack", Popul Ecol 52:279-287, 2010) reports conclusions that are unsupportable, in our opinion, due to both mis-interpretations of current knowledge regarding the wolverine's (Gulo gulo) association with snow, and the uncritical use of harvest data to index wolverine populations. The authors argue that, because the wolverine is a snow-dependent species, average annual provincial snowfall, based on weather station data, can be expected to correlate strongly and positively with wolverine population numbers, which in turn can be accurately indexed by trapper harvests. Thus, correlations between declines in wolverine harvests and declining average snowpack are interpreted to reflect a climate-driven decrease in wolverine populations. This conclusion overstates the nature of the wolverine's association with snow, and makes unsupportable assumptions about the reliability of harvest data as a proxy for population size. © 2010 The Author(s).


Copeland J.P.,Rocky Research | McKelvey K.S.,Rocky Research | Aubry K.B.,U.S. Department of Agriculture | Landa A.,Norwegian Institute for Nature Research | And 13 more authors.
Canadian Journal of Zoology | Year: 2010

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.


Short J.,Wildlife Research and Management | Short J.,Murdoch University | Hide A.,Wildlife Research and Management | Stone M.,Wildlife Research and Management
Wildlife Research | Year: 2011

Context The red-tailed phascogale once occurred widely across semiarid and arid Australia, but is now confined to the southern wheatbelt of Western Australia. Its apparently extensive former range suggests a broad habitat tolerance, yet it is now reported primarily from remnant vegetation within farmland containing wandoo Eucalyptus wandoo and rock sheoak Allocasuarina huegeliana associations. Aims To establish the habitat requirements of phascogales with a view to understanding their current and likely future distribution and status. Methods We established presence or absence of phascogales at a number of sites within their current range, primarily by trapping, and then compared habitat attributes between the two classes of sites to establish those of apparent significance to species persistence. Key results Phascogales are widespread in suitable upland (wandoorock sheoak) and lowland habitat (riverine fringing vegetation of swamp sheoak Casuarina obesa, York gum E. loxophleba and wandoo). They occupy areas of remnant vegetation of varying sizes from very small to very large, many on private agricultural land. Large connected areas, such as riverine corridors and clusters of upland remnants appear important to their long-term persistence. Sites isolated by increasing distance from another occupied site tended to be unoccupied. Habitats occupied by phascogales typically had a greater canopy density and greater abundance of hollows than unoccupied sites. The presence of plants of the genus Gastrolobium, often cited as a key factor in the persistence of phascogales, did not appear to influence the presence or absence of phascogales. Conclusions Red-tailed phascogales currently occupy a broader range of habitats than identified in the literature and the role of some key aspects of habitat in protecting them from further decline may have been overstated. The presence of suitable hollows for nesting and shelter and a dense mid-storey canopy, perhaps to protect from predation by owls, are key features of suitable phascogale habitat. Implications Suitable habitat for phascogales appears widespread in the surveyed portion of the remaining range of the species, but is under threat over the longer term. Increasing salinity in lowland areas (which transforms woodland to samphire with a consequent long-term loss of nesting hollows), lack of fire in upland areas to maintain dense stands of rock sheoak and the increasing loss of corridors of vegetation along roadsides due to the widening of roads by local councils are all contributing to loss of habitat and habitat connectivity. © 2011 CSIRO.


Short J.,Wildlife Research and Management | Short J.,Murdoch University | Hide A.,Wildlife Research and Management
Australian Mammalogy | Year: 2012

The red-tailed phascogale once extended widely across semiarid and arid Australia, but is now entirely confined to the southern wheatbelt of Western Australia, occupying less than 1% of its former range. Here it occurs in a portion of the Avon Wheatbelt, Jarrah Forest, Mallee, and Esperance Plains biogeographical regions. The species persists only in areas that have been extensively cleared for agriculture and where the remaining bushland is highly fragmented. It does not appear to extend into unfragmented habitat in either the Jarrah Forest to the west or Mallee region to the east. It occurs primarily in woodland habitat with old-growth hollow-producing eucalypts, primarily wandoo (Eucalyptus wandoo) or York Gum (E. loxophleba), but records from the periphery of its current range appear to come from a broader range of habitats, including shrublands and various mosaics of woodland, shrubland, and scrub-heath. Key factors limiting persistence are likely to be fragmentation of habitat that is likely to greatly increase the risks associated with dispersal, a shortage of suitable nesting hollows in many vegetation associations, and predation by feral and domestic cats and by foxes. These factors, particularly fragmentation and lack of suitable nesting hollows, suggest that the species' long-term persistence in areas beyond the wandoo belt is far from assured. © 2012 Australian Mammal Society.


Short J.,Wildlife Research and Management | Short J.,Murdoch University
Wildlife Research | Year: 2016

Context Reintroduction of endangered species potentially places them back in contact with putative factors of historical decline, inadvertently providing the opportunity to evaluate their impact. Aims To monitor the long-term progress of a population of western barred bandicoot reintroduced to mainland Australia and to assess factors involved in its eventual local extinction. Methods Bandicoots were reintroduced from offshore Dorre Island to the nearby mainland peninsula of Heirisson Prong in 1995. The narrow neck of the peninsula was fenced to exclude foxes and feral cats from a 1200ha area, but the area was subject to periodic incursions. There was parallel management of a confined but unsupported population in an in situ 17-ha predator refuge. Bandicoots were assessed for abundance, body condition and reproduction two to four times annually between 1995 and 2010. In addition, perceived threatening processes (drought, disease and the abundance of cats, foxes and rabbits) were monitored. Key results Bandicoots became well established at the site, spreading to all available habitat. Numbers fluctuated strongly, peaking at ~250 in 1999 and then declining to apparent local extinction (with subsequent re-establishment from the refuge), and at ~470 animals in 2006, followed again by extinction. Conclusions Predation by feral cats was implicated as the primary cause of both free-range extinctions and the eventual elimination of all bandicoots from the predator refuge. Other contributing factors in one or more of the declines were a reduction in reproduction and recruitment in bandicoots during a one-in-100-year drought, the impact of overabundant European rabbits on vegetation used by bandicoots for nesting shelter and brief fox incursions at key times. Implications Existing methods of control of feral cats are rendered ineffective in the presence of abundant and diverse native fauna and abundant exotic species (particularly European rabbits). In addition, episodic drought in arid Australia intensifies the impact of predation by restricting reproduction of prey species. These factors hamper the attempts of conservation managers to re-establish vulnerable species at sites other than those with the infrastructure and/or management intensity to largely exclude exotic predators (and preferably European rabbits) over the long-term. © The authors 2016.


Bowman J.,Ontario Ministry of Natural Resources | Ray J.C.,Wildlife Conservation Society | Magoun A.J.,Wildlife Research and Management | Johnson D.S.,National Oceanic and Atmospheric Administration | Neil Dawson F.,Ontario Ministry of Natural Resources
Canadian Journal of Zoology | Year: 2010

We evaluated hypotheses concerning the distributions of large mammals in a 60 000 km2 study area that encompassed the contact zone between Ontario's roadless north and the postlogging southern landscape. We estimated occurrence probability in 575 sample units for woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)), wolverine (Gulo gulo (L., 1758)), gray wolf (Canis lupus L., 1758), moose (Alces alces (L., 1758)), and white-tailed deer (Odocoileus virginianus (Zimmerman, 1780)). We used ordinations and spatial regressions to assess the contributions of parameters to species occurrence. Roads and cutovers were most abundant in the south, leading to an increased prevalence of deciduous forest. Mature coniferous forest, however, occurred most commonly in the north. Occurrence probabilities for moose and deer were greatest in the south, in close association with deciduous trees. Wolf occurrence was also greatest in the south, positively related to both deciduous forest and road density. Caribou occurrence, however, was positively related to mature coniferous forest and negatively related to both wolf occurrence and roads. Wolverine occurrence was negatively related to deciduous forest. Our surveys demonstrated distinct mammal communities in the northern and southern halves of our study area, a separation that appeared to be mediated by deciduous forest and roads.


Inman R.M.,Wildlife Conservation Society | Inman R.M.,Swedish University of Agricultural Sciences | Magoun A.J.,Wildlife Research and Management | Persson J.,Swedish University of Agricultural Sciences | And 2 more authors.
Journal of Mammalogy | Year: 2012

Wolverines are demographically vulnerable and susceptible to impacts from climate change. Their distribution is correlated with persistent spring snow cover, but food-based explanations for this relationship have not been explored. We synthesize information on the timing of both wolverine reproductive events and food availability to improve our understanding of the behaviors, habitat features, and foods that influence reproductive success. Wolverine births are constrained to a brief period of the year and occur at an earlier date than other nonhibernating, northern carnivores. Our examination suggests that this timing is adaptive because it allows wolverines to take advantage of a cold, low-productivity niche by appending the scarce resources available during winter to the brief period of summer abundance. The wolverine's bet-hedging reproductive strategy appears to require success in 2 stages. First, they must fuel lactation (FebruaryApril) with caches amassed over winter or acquisition of a sudden food bonanza (e.g., winter-killed ungulates); otherwise, early litter loss occurs. Next, they must fuel the majority of postweaning growth during the brief but relatively reliable summer period of resource abundance. The 1st stage is likely dependent on scavenged ungulate resources over most of the wolverine's range, whereas the 2nd stage varies by region. In some regions the 2nd stage may continue to be focused on scavenging ungulate remains that have been provided by larger predators. In other regions the 2nd stage may be focused on predation by wolverines on small prey or neonatal ungulates. During all seasons and regions, caching in cold, structured microsites to inhibit competition with insects, bacteria, and other scavengers is likely a critical behavioral adaptation because total food resources are relatively limited within the wolverine's niche. Habitat features that facilitate caching, e.g., boulders and low ambient temperatures, are likely important and could be related to the limits of distribution. This "refrigeration-zone" hypothesis represents a food-based explanation for the correlation between wolverine distribution and persistent spring snow cover. Understanding regional differences in foods that fuel reproduction and underlying causes to the limits of distribution could be important for maintaining wolverine populations in the future. © 2012 American Society of Mammalogists.

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