Canis Lupus Cosmopolis: Wolves in a Cosmopolitan Worldview
Lynn, W., World Views: Environment, Culture, Religion, 6/3 (2002): 300-327
The subject of wolf recovery in North America sparks heated controversy, both for and against. This paper explores how this subject is informed by cosmopolitan worldviews. These worldviews pull nature and culture into a common orbit of ethical meaning, with implications for the normative relationships that ought to pertain in landscapes shared by people and wolves. This theoretical outlook is illustrated using the controversy over wolves in the northeastern region of the United States. I conclude with a set of reflections on theorizing the cosmopolis, the interpretation of cosmopolitan landscapes, and living with cosmopolitan wolves.
Characteristics of Wolf Packs Depredating on Domestic Animals in Wisconsin, USA
Treves, A.; Wydeven, A.P.; Brost, B.; Wiedenhoeft, J.E., World Wolf Congress
Not all wolf packs prey on domestic animals despite having the opportunity. Long-term data from Wisconsin shows that 40% of wolf packs have been implicated in conflicts with humans. This subset of the population is distinguished by their average pack size and proportion of forest in and around their territory. Wolf packs that preyed on hunting dogs were larger than other packs, while those that preyed on livestock were the smallest of the problem packs. Wolf packs that preyed on domestic animals lived in more forested areas than packs never implicated in depredations. Wolf packs implicated in livestock depredation had smaller territories on average than other packs. About 46% of wolf packs implicated in dog depredation in one year, did so again in subsequent years. Livestock depredations were repeated by the same pack in 33-53% of subsequent years. Our results can help to guide interventions by wolf managers, especially when conflicts with free-roaming dogs and hunters are severe.
Climate and Habitat Barriers to Dispersal in the Highly Mobile Grey Wolf
Geffin, E.; Anderson, M.; Wayne, R.K., Molecular Ecology, 13/8 (August 2004), 2481 (10pp)
We reanalysed published data to evaluate whether climate and habitat are barriers to dispersal in one of the most mobile and widely distributed mammals, the grey wolf (Canis lupus). Distance-based redundancy analysis (dbRNA) was used to examine the amount of variation in genetic distances that could be explained by an array of environmental factors, including geographical distance. Patterns in genetic variation were also examined using MDS plots among populations and relationships between genetic structure and individual environmental variables were further explored using the BIOENV procedure. We found that, contrary to a previous report, a pattern of isolation with distance is evident on a continental scale in the North American wolf population. This pattern is apparently related to climate and habitat. Specifically, vegetation types appear to play a role in the genetic dissimilarities among populations. When we controlled for the effect of spatial variation, climate was still associated with genetic distance. Further, partitioning of geographical distances into latitudinal and longitudinal axes revealed that the east-west gradiant had the strongest relationship with genetic distance. We suggest two possible mechanisms by which environmental conditions may influence the dispersal decisions made by wolves.
Color Patterns Among Wolves in Western North America
Gipson, P.S.; Bangs, E.E.; Bailey, T.N.; Boyd, D.K., et al, Wildlife Society Bulletin, 30/3 (Fall 2002)
Pelt color of wolves (Canis lupus) is a highly visible characteristic that has been used in studies of taxonomy, and yet no comprehensive analysis of color variation in wolves has been conducted. We compiled observations from our wolf research, records from wildlife management agencies, and published accounts to document occurrence and distribution of pelt colors, and changes in individual wolves from black or gray to white, Less than 2% of wolves were white in North America. The proportion of white wolves increased northward from the taiga through the High Arctic of Canada and Greenland, where >90% of wolves were white or near white. Wolves that were white as pups probably remained white throughout adult life. Black wolves appeared to remain black or progressively changed to bluish-silver, silver, or white. Black wolves commonly had a white chest spot and white toes that faded with age. Gray-colored wolves may change to cream or white. Whitening among wolves may be influenced by 1) advancing age, 2) physiological stress, and 3) inheritance of genes that tend to be expressed as white.
Comment: Regulation of Moose Populations by Wolf Predation
Messier, F.; D. Joly, Canadian Journal of Zoology, 78 (March 2000): 506-510 (5pp)
We discuss regulation of moose (Alces alces) populations by wolves (Canis lupus) in the context of a recent article by Eberhardt (L.L. Eberhardt. 1997. Can. J. Zool. 75: 1940-1944), who contended that the killing rate of moose by wolves was constant. Further, he argued that wolf population size was proportional to prey density, and that wolf predation exerted a regulatory effect on ungulate-prey numbers. We argue that this combination of functional and numerical responses results in density-independent predation that cannot regulate prey numbers. We discuss the present understanding of wolf-moose interactions and conclude that there is evidence suggesting density dependence in both functional and numerical responses. Further, we conclude that predation by wolves is density-dependent, at least at low moose densities, and therefore can act as a regulatory factor.
Combined Use of Maternal, Paternal and Bi-parental Genetic Markers for the Identification of Wolf-Dog Hybrids
Vila.; Walker, C.; Sundqvist, A-K.; Flagstad, O.; Andersone, Z.; Casulli, A.; Kojola, I.; Valdmann, H.; Halverson, J.; Ellegren, H., Heredity, 90/1, January 2003, 17 (8pp)
The identification of hybrids is often a subject of primary concern for the development of conservation and management strategies, but can be difficult when the hybridizing species are closely related and do not possess diagnostic genetic markers. However, the combined use of mitochondrial DNA (mtDNA), autosomal and Y chromosome genetic markers may allow the identification of hybrids and of the direction of hybridization. We used these three types of markers to genetically characterize one possible wolf-dog hybrid in the endangered Scandinavian wolf population. We first characterized the variability of mtDNA and Y chromosome markers in Scandinavian wolves as well as in neighboring wolf populations and in dogs. While the mtDNA data suggested that the target sample could correspond to a wolf, its Y chromosome type had not been observed before in Scandinavian wolves. We compared the genotype of the target sample at 18 autosomal microsatellite markers with those expected in pure specimens and in hybrids using assignment tests. The combined results led to the conclusion that the animal was a hybrid between a Scandinavian female wolf and a male dog. This finding confirms that inter-specific hybridization between wolves and dogs can occur in natural wolf populations. A possible correlation between hybridization and wolf population density and disturbance deserves further research.
Common Ravens, Corvus corax, Preferentially Associate with Grey Wolves, Canis lupus, as a Foraging Strategy in Winter
Stahler, D.; Heinrich, B.; Smith, D., Animal Behaviour, 64/2 (August 2002)
One foraging strategy that scavengers can employ to discover unpredictable food sources is to associate directly with predators who inadvertently provide food. The common raven, a well known feeding generalist, is also a prominent scavenger of wolves' kills and is found to be in close association with this predator. We tested the hypothesis that ravens preferentially associate with wolves in winter as a kleptoparasitic foraging strategy. The presence, absence and behaviour of ravens was documented during winter observations of wolves, coyotes, Canis latrans, and elk, Cervus elaphus, as well as the landscape in the absence of these three species. Ravens were found to be in close association with wolves when they were travelling, resting and hunting prey. In comparison, ravens showed no significant association with coyotes, elk or areas on the landscape in the absence of wolves. We also compared ravens' discovery success of wolf-killed and nonwolf-killed carcasses and their behavioural response upon discovery. Ravens found all wolf kills almost immediately and remained at the carcass to feed alongside wolves after the death of the prey. In contrast, ravens were less successful discovering experimentally placed carcasses in the same study region, and did not land or feed despite the availability of fresh, exposed meat. Our results show that ravens' association with wolves is not just an incidental and proximate by-product of the presence of fresh meat. Instead, we show that ravens preferentially associate with wolves in both the presence and absence of food, resulting in the discovery of carcasses and suppression of ravens' innate fear of novel food sources. Through this mode of social foraging, ravens may experience increased foraging efficiency in the use of an otherwise spatially and temporally unpredictable food source.
Computer Simulation of Vasectomy for Wolf Control
Haight, R.G.; Mech, L.D., Journal of Wildlife Management, 61/4 (October 1997)
Recovering gray wolf (Canis lupus) populations in the Lake Superior region of the United States are prompting state management agencies to consider strategies to control population growth. In addition to wolf removal, vasectomy has been proposed. To predict the population effects of different sterilization and removal strategies, we developed a simulation model of wolf dynamics using simple rules for demography and dispersal.
Computer Simulation of Wolf-Removal Strategies for Animal Damage Controlrol
Haight, R.G.; Travis, L.E.; Nimerfro, K.; Mech, L.D., Wildlife Society Bulletin, 30/3 (Fall 2002)
Because of the sustained growth of the gray wolf (Canis lupus) population in the western Great Lakes region of the United States, management agencies are anticipating gray wolf removal from the federal endangered species list and are proposing strategies for wolf management. Strategies are needed that would balance public demand for wolf conservation with demand for protection against wolf depredation on livestock, poultry, and pets. We used a stochastic, spatially structured, individually based simulation model of a hypothetical wolf population, representing a small subset of the western Great Lakes wolves, to predict the relative performance of 3 wolf-removal strategies. Those strategies included reactive management (wolf removal occurred in summer after depredation), preventive management (wolves removed in winter from territories with occasional depredation), and population-size management (wolves removed annually in winter from all territories near farms). Performance measures included number of depredating packs and wolves removed, cost, and population size after 20 years. We evaluated various scenarios about immigration, trapping success, and likelihood of packs engaging in depredation. Four robust results emerged from the simulations: 1) each strategy reduced depredation by at least 40% compared with no action, 2) preventive and population-size management removed fewer wolves than reactive management because wolves were removed in winter before pups were born, 3) population-size management was least expensive because repeated annual removal kept most territories near farms free of wolves, and 4) none of the strategies threatened wolf populations unless they were isolated because wolf removal took place near farms and not in wild areas. For isolated populations, reactive management alone ensured conservation and reduced depredation. Such results can assist decision makers in managing gray wolves in the western Great Lakes states.
Conservation and Control Strategies for the Wolf (Canis lupus) in Western Europe Based on Demographic Models
Chapron, G.; Legendre, S.; Ferriere, R.; Clobert, J.; Haight, R.G., Comptes Rendus Biologies, 326/6 (June 2003), 575 (13pp)
Securing the long-term acceptance of large carnivores such as the wolf (Canis lupus) in Europe and North America raises a difficult challenge to conservation biologists: planning removals to reduce depredations on livestock while ensuring population viability. We use stochastic-stage-structured population models to investigate wolf population dynamics and to assess alternative management strategies. Among the various management strategies advocated by agencies, zoning that involves eliminating wolves outside a restricted area should be designed with caution, because probabilities of extinction are extremely sensitive to the maximum number of packs that a zone can support and to slight changes in stage specific survival probabilities. In a zoned population, viability is enhanced more by decreasing mortality rates in all classes than by increasing wolf zone size. An alternative to zoning is adaptive management, where there is no limit on pack number but population control can be operated whenever some predefined demographic conditions are met. It turns out that an adaptive management strategy that removes a moderate percentage (<f>10%</f>) of the population following each year of more than <f>5%</f> of total population growth would provide visible actions addressing public concerns while keeping extinction probability low. To cite this article: G. Chapron et al., C. R. Biologies 326 (2003).
Constraints on Active-Consumption Rates in Gray Wolves, Coyotes, and Grizzly Bears
Wilmers, C.; Stahler D,, Canadian Journal of Zoology, 80 (July 2002): 1256-1261 (6 pp)
Predators' feeding strategies lie on a continuum between energy maximizers, who maximize the energy obtained from a patch of food, and time minimizers, who minimize the time required to get a fixed ration of food from a patch. Carnivores that feed on large prey should adopt a time-minimizing strategy by maximizing their active-consumption rate (ACR) if they evolved under conditions of high competition from group members, and conversely adopt an energy-maximizing strategy if they evolved under conditions of low competition from group members and were thus able to monopolize their prey. By provisioning animals with large pieces of ungulate carcasses, we measured ACR for captive gray wolves (Canis lupus), coyotes (Canis latrans), and grizzly bears (Ursus arctos). In accordance with a conspecific-competition hypothesis, ACR increased with sociality. Other factors influencing ACR included subject body mass and food type, ACR being significantly faster on muscle and organs than on bone and hide. Measuring ACR is crucial to empirical and theoretical studies assessing foraging decisions and may be used as an indicator of an animal's competitive environment.
Contested Natures: Wolves in Late Modernity
Kleese, D,. Society & Natural Resources, 15/4 (April 2002), 313 (14pp)
This article examines some characteristics of the late modern period and the impacts of these characteristics on wolf conservation. As we move beyond the year 2000, characteristics of late modernity become especially relevant for understanding conservation. First, conservation efforts must operate in the territory in between: Nature can no longer be regarded as operating solely outside of the social purview, and society cannot be regarded as separate from nature. Second, as more and more areas of life move under the control of human agency, we need to rethink the importance of human action for the care and protection of the biophysical world. Finally, the impact of a globalized present has changed the very nature of conservation; the incredible speed of information, time and awareness of environmental problems erodes the boundaries between people, species, and their physical environments.
Coyote Foraging Ecology and Vigilance in Response to Gray Wolf Reintroduction in Yellowstone National Park
Switalski, T., Canadian Journal of Zoology, 81 (June 2003): 985-993 (9 pp)
Coyotes (Canis latrans) in Yellowstone National Park (YNP) have lived in the absence of wolves (Canis lupus) for over 60 years. I examined whether wolf reintroduction in 1995 and 1996 in YNP influenced coyote vigilance and foraging ecology. From December 1997 to July 2000, my co-workers and I collected 1708 h of coyote activity budgets. Once wolves became established in the Park, they once again provided a continuous source of carrion in the Lamar Valley and we found that coyotes began feeding on carcasses throughout the year. Although we documented that wolves killed coyotes, it also became clear that surviving coyotes quickly adjusted their behaviors when wolves were present. When coyotes were near wolves or in areas of high wolf use, they fed on carcasses much more; however, they increased the amount of time spent in vigilance activities and decreased rest. There appears to be a trade-off in which wolf kills provide a quick source of food that is energetically advantageous to coyotes; however, attendant costs included increased vigilance, decreased rest, and a higher risk of being killed. Changes in the behavior of coyotes in response to the reintroduction of this large carnivore may ultimately have wide-ranging cascading effects throughout the ecosystem.
A 'Curious and Grim Testimony to a Persistent Human Blindness': Wolf Bounties in North America, 1630–1752
Barclay, P.D., Ethics, Place & Environment, 5/1 (March 2002), 25 (10pp)
The North American wolf became extinct east of the Appalachians by 1800. To colonial legislators, uniform, colony-wide wolf bounties, as incentives to wolf-extermination, seemed the simplest solution to a perceived threat to livestock and European settlements. To local taxpayers, considerations of parsimony and fraud loomed just as large. This tension led to wolf extermination policies that were costly and often counterproductive. The bounty laws, as enacted, amounted to a fight against the abstract wolf, instead of against individual predators. Its eventual 'success' brought about new troubles. Absent wolves, the eastern seaboard's ecosystem re-adjusted, allowing new predators and pests to flourish.
Current Development and Future Directions in Non-Lethal Wolf Predation Management
Shivik, J.A.; Breck, S.W.; Treves, A.; Callahan, P., World Wolf Congress 2003
We have developed the Radio Activated Guard (RAG) and the Motion Activated Guard (MAG) and tested these and other techniques, such as fladry and electronic training collars, for wolf predation management. In a multi-predator study on six wolf territories in Wisconsin, the average weight of carcass consumption was similar on all plots before treatments were applied; when treatments (MAG, fladry, or control) were applied, however, we found that average daily consumption on MAG protected plots was 68% less than on control plots, but consumption on the fladry plots was not statistically less than on the control plots. Our previous study using electronic training collars on wild wolves produced equivocal results, with no clear aversions formed, primarily due to logistical considerations, and in a follow-up study on captive wolves, less food was consumed using MAG devices than in the control treatment, but effectiveness of the training collar was not evident due to behavioral variability in response to collars. The MAG device, although effective in the short term, did not cause a learned aversion. We have developed effective non-lethal methods and continue to promote their appropriate use. Other scientists and managers with limited resources have expressed frustration with the complexity and expense of developing and using non-lethal techniques, but conflicts with wolves are likely to increase, and development of these tools is necessary for wolves and other predators.
Current Status of the Gray Wolf, Its Prey and Human-Wolf Interaction in Turkey
Emre, C.; Butzler, W.; Togan, I., World Wolf Congress 2003
The lack of information on wolf population hinders planning of wolf management in Turkey. The exact distribution of wolves is not known...and the authorities think that wolves cause significant damage to livestock industry. Therefore, wolves are listed as [a] pest species in Turkish legislation. To gather baseline data about wolves in Turkey, we have studied the distribution of wolves in Bolu in Central Anatolia by snow tracking from January to April 1999. We have...distributed 450 questionnaires in an area of 73,863 km2 in southeastern Turkey to reveal the presence of wolves and wolf-human conflict in 2001. We have also interviewed key local authorities and locals about wolf presence in different regions of Turkey between 1999-2002. Our results indicated that the presence of wolves was highly determined by the presence of wild boar and brown hair....We estimated the density of wolves as 2.2 to 2.8 wolves per 100 km2 in Bolu. The wolf-caused mortality for the wild boar was estimated to be more than 16% and human-caused mortality for the study population was 29-36% in Bolu. The initial analysis of the questionnaires showed that the perception of the wolf differs among local people and eradication of wolves by all possible means has been ongoing....The future of wolves depends on limiting the conflict between wolves and humans, recovery of declining prey populations and planning wolf management in Turkey.