COOPERATIVE WOLF DEPREDATION MANAGEMENT IN WISCONSIN

A depredation management plan was an important component of Federal and State recovery plans for the endangered gray wolf (Canis lupus) in Wisconsin. The Wisconsin Department of Natural Resources (WDNR) entered into a cooperative agreement with USDA-APHIS-ADC to cooperatively manage wolf depredations. Response to complaints involving wolf-dog hybrids was also part of the cooperative agreement. From 1990-1996 ADC investigated 60 wolf complaints and confirmed 10 depredations. In the same time period, WDNR paid a total of $21,376 in compensation payments for 21 incidents of wolf depredations. Wolves may be downlisted from endangered to threatened within the next five years. As the wolf population increases so will the need for effective response to depredations

Wolves facilitate the recovery of browse-sensitive understory herbs in Wisconsin forests

We asked whether wolf re-colonization would facilitate increased growth and reproduction of three browse-sensitive plant species. We hypothesized plant size and the proportion of reproductive individuals would be lowest in areas with no wolves, intermediate where wolves had been present for 4-6 years, and highest where wolves had been present for 12-13 years. Two plant species exhibited significantly greater reproduction where wolves were present for 12-13 years. Mean leaf size of indicator plants was significantly greater in areas where wolves were present for 12-13 years, as compared with that in areas where wolves were not present or were present for 4-6 years, but the effect size appears small. While the return of wolves to this region is likely to benefit browse-sensitive plant species, our findings suggest that wolf recovery will not generate atrophic cascade of sufficient magnitude to halt or reverse the loss of plant diversity in the Great Lakes region in the near term

Death of Gray Wolves, Canis lupus, in Porcupine Erethizon dorsatum, Dens in Wisconsin

Three Gray Wolves (Canis lupus) were found dead in porcupine (Erethizon dorsatum) dens in northern Wisconsin between 1996-2000. Use of these dens appeared to be cases of shelter-seeking behavior by wolves suffering from sarcoptic mange

Attempt to Cross-Foster Gray Wolf, Canis lupus, Pups into Another Wolf Pack

We attempted to cross-foster four 18-19 week-old Gray Wolf (Canis lupus) pups into another Wolf pack 182 km from their natal pack territory. The pup introduction was the result of depredation control on a farm in northwestern Wisconsin. Three pups died within 14 days of release. A fourth pup survived along the edge of the new pack territory over winter, dispersed in the spring, joined or formed a new pack and was captured on a depredation complaint four years later

Effectiveness of a Simulated Pack to Manipulate Wolf Movements

Bioboundaries, also called biofences, are deterrents that attempt to exploit certain innate behaviors to exclude wildlife from target areas. We hypothesized that human-deployed scent marks and playbacks of foreign howls could simulate a territorial gray wolf (Canis lupus) pack impinging on a resident pack, thereby causing the resident pack to move. During summer 2010, we deployed a simulated-pack bioboundary near 3 wolf packs in northern Wisconsin and monitored their movements relative to 3 wolf packs experiencing a sham treatment, to control for effects of human presence. We analyzed wolves’ locations (≥1 location per week) and used linear models with mixed effects to examine distance from the rendezvous site as a function of treatment (sham or experimental) and phase of treatment (before or after treatment was initiated), while accounting for variations in individual wolves. We found little evidence that biofences, as configured and deployed in this study, caused wolves to change use of their territory

Death of Gray Wolves, <em>Canis lupus</em>, in Porcupine <em>Erethizon dorsatum</em>, Dens in Wisconsin

Three Gray Wolves (Canis lupus) were found dead in porcupine (Erethizon dorsatum) dens in northern Wisconsin between 1996-2000. Use of these dens appeared to be cases of shelter-seeking behavior by wolves suffering from sarcoptic mange

Gray Wolf Recovery Precipitates a Species-Specific Trophic Cascade in the Upper Great Lakes Region

High densities of white-tailed deer throughout eastern North America have been implicated in changing forest community structure and composition. We hypothesized that the recovery of an apex predator, the gray wolf (Canis lupus), in a region affected by deer overabundance could reduce browsing impacts on vegetation via a trophic cascade. We tested this hypothesis by surveying an herbaceous forest understory species sensitive to deer browsing (Polygonatum pubescens) in areas of northern Wisconsin where wolves have re-colonized over the past 20 years. We used a natural experimental framework, surveying populations in areas that lack wolves (nonwolf, n = 3 sites), areas where wolves have been established for 3-5 years (3 sites), and areas where wolves have been established for 9-11 years (3 sites). Each site consisted of five 10m x 10m plots. We compared these populations to plants growing in deer exclosures continuously maintained for 15 years. The number of leaves per plant and percent flowering was recorded for 1,579 plants

Recolonizing Wolves Trigger a Trophic Cascade in Wisconsin

We tested the hypothesis that wolves are reducing local browse intensity by white-tailed deer, thus indirectly mitigating the biotic impoverishment of understorey plant communities in northern Wisconsin. To assess the potential for such a top-down trophic cascade response, we developed a spatially and temporally explicit model of wolf territory occupancy based on three decades of wolf monitoring data. Using a nested multiscale vegetation survey protocol, we compared the understorey plant communities of northern white cedar wetlands found in high wolf areas with control sites found in low wolf areas. We fit species–area curves for plant species grouped by vegetation growth form (based on their predicted response to release from herbivory, i.e. tree, seedling, shrub, forb, grass, sedge or fern) and duration of wolf territory occupancy. As predicted for a trophic cascade response, forb species richness at local scales (10 m2) was significantly higher in high wolf areas (high wolf areas: 10.7 ± 0.9, N = 16, low wolf areas: 7.5 ± 0.9, N = 16, P \u3c 0.001), as was shrub species richness (high wolf areas: 4.4 ± 0.4, N = 16, low wolf areas: 3.2 ± 0.5, N = 16, P \u3c 0.001). Also as predicted, percentage cover of ferns was lower in high wolf areas (high wolf areas: 6.2 ± 2.1, N = 16, low wolf areas: 11.6 ± 5.3, N = 16, P \u3c 0.05). Beta richness was similar between high and low wolf areas, supporting earlier assumptions that deer herbivory impacts plant species richness primarily at local scales. Sampling at multiple spatial scales revealed that changes in species richness were not consistent across scales nor among vegetation growth forms: forbs showed a stronger response at finer scales (1–100 m2), while shrubs showed a response across relatively broader scales (10–1000 m2). Synthesis. Our results are consistent with hypothesized trophic effects on understorey plant communities triggered by a keystone predator recovering from regional extinction. In addition, we identified the response variables and spatial scales appropriate for detecting such differences in plant species composition. This study represents the first published evidence of a trophic cascade triggered by wolf recovery in the Great Lakes region

Gray Wolf Exposure to Emerging Vector-Borne Diseases in Wisconsin with Comparison to Domestic Dogs and Humans

<div><p>World-wide concern over emerging vector-borne diseases has increased in recent years for both animal and human health. In the United Sates, concern about vector-borne diseases in canines has focused on Lyme disease, anaplasmosis, ehrlichiosis, and heartworm which infect domestic and wild canids. Of these diseases, Lyme and anaplasmosis are also frequently diagnosed in humans. Gray wolves (<i>Canis lupus</i>) recolonized Wisconsin in the 1970s, and we evaluated their temporal and geographic patterns of exposure to these four vector-borne diseases in Wisconsin as the population expanded between 1985 and 2011. A high proportion of the Wisconsin wolves were exposed to the agents that cause Lyme (65.6%) and anaplasma (47.7%), and a smaller proportion to ehrlichiosis (5.7%) and infected with heartworm (9.2%). Wolf exposure to tick borne diseases was consistently higher in older animals. Wolf exposure was markedly higher than domestic dog (<i>Canis familiaris</i>) exposure for all 4 disease agents during 2001–2013. We found a cluster of wolf exposure to <i>Borrelia burgdorferi</i> in northwestern Wisconsin, which overlaps human and domestic dog clusters for the same pathogen. In addition, wolf exposure to Lyme disease in Wisconsin has increased, corresponding with the increasing human incidence of Lyme disease in a similar time period. Despite generally high prevalence of exposure none of these diseases appear to have slowed the growth of the Wisconsin wolf population.</p></div

Temporal trend in wolf seroprevalence to <i>B</i>. <i>burgdorferi</i> and <i>E</i>. <i>canis</i> in Wisconsin during 1985 to 2011.

<p>For both pathogens years were grouped into the following 5 groups: 1985–1990 (n = 13), 1991–1996 (n = 40), 1997–2001 (n = 62), 2002–2006 (n = 109 and 108 for <i>B</i>. <i>burgdorferi</i> and <i>E</i>. <i>canis</i>, respectively), and 2007–2011 (n = 148 and 147 for <i>B</i>. <i>burgdorferi</i> and <i>E</i>. <i>canis</i>, respectively). Data points represent the observed prevalence of wolf exposure within a period. Vertical bars represent 95% confidence interval (CI). Coefficient estimate for <i>B</i>. <i>burgdorferi</i> = -0.05 (P = 0.03, 95% CI = 0.0–0.09, Odds Ratio = 1.05, 95% CI = 1.0–1.05). Coefficient estimate for <i>E</i>. <i>canis</i> = -0.09 (P = 0.026; CI = -0.16 –-0.01, Odds Ratio = 0.92, CI = 0.85–0.99).</p