WISCONSIN ENDANGERED RESOURCES REPORT #140
YEAR END SUMMARY
WOLF POPULATION MONITORING
IN WISCONSIN IN 2010The gray wolf (Canis lupus) was eliminated from Wisconsin in the late 1950s, but returned to the state in the mid-1970s. The Wisconsin wolf population has been intensely monitored by the Wisconsin Department of Natural Resources (DNR) every year since fall 1979, using radio-telemetry, snow-track surveys, summer howl surveys, collection and necropsies on dead wolves, and collection of wolf observations (Wydeven et al. 2009). Population estimates have been made since winter 1979-1980 when 25 wolves were detected, to winter 2009-2010 when a minimum count of 690 wolves were detected (Wydeven et al. 2010). The gray wolf was listed as state endangered in 1975, state downlisted to threatened in 1999, and state delisted to protected wild animal in 2004. Federally, the gray wolf or eastern timber wolf (Canis lupus lycaon) was listed as endangered in Wisconsin in 1967 and 1974. The US Fish and Wildlife Service (USFWS) federally downlisted wolves to threatened status in April 2003, but relisted wolves to endangered status in January 2005 due to lawsuits. Gray wolves were delisted by USFWS in Wisconsin on 12 March 2007, but relisted as endangered on 29 September 2008 due to a lawsuit. Wolves were again delisted on 4 May 2009, but again relisted on 1 July 2009 because of threat of lawsuit. New efforts for federal delisting are planned for spring 2011, and are anticipated to be completed by late 2011.
Thus currently wolves are listed as a state protected wild animal, but continue to be federally listed as endangered. Wolves were listed as federally endangered throughout 2010, and no authority for limited lethal controls on wolves depredating on domestic animals were granted by USFWS, as had been done in 2005 and 2006. Thus the only lethal controls possible by the Wisconsin DNR and its partner USDA-Wildlife Services, was on wolves that show risk to human safety. The enclosed report summarizes data collected in 2010. A more extensive report on wolf conservation work in Wisconsin will be completed in September 2011.
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Wolf Captures
Thirty-five wolves were live-captured and radio-collared in 2010 (Table 1). Collars were placed on 24 of 181 packs (13%) detected in the state in winter 2010, and on 2 packs not previously detected (Chittamo& Scotchman Lake). Collars were also placed on 5 wolves that mainly appeared to be loners/dispersers. Eight wolves were captured by fur trappers in the fall and turned over to WDNR for radio-collaring. The other 27 wolves were captured by WDNR, USDA-WS, and tribal trappers. Captured wolves included: 11 adult males (X= 79.4 lbs. + 6.9 SD for 10), 6 adult females (63.5 lbs. + 7.5 SD), 4 yearling males (X=67.5 lbs. + 11.5 SD), 12 yearling females (X= 63.7 lbs + 6.1 SD for 11), 1 pup male (30 lbs.) and 1 pup female (60 lbs).
Radio Collared Wolves Monitored in 2010
A total of 91 radio collared wolves were monitored during portions of 2010 (Table 2). Radio-collared wolves monitored during the year included 68 Wisconsin packs, 2 Minnesota packs, and 1 wolf dispersing in Michigan. Wisconsin packs with collared wolves included 65 or 36 % of the 181 packs detected in winter 2010 (Wydeven et al. 2010). One pack detected during the winter survey went extinct and was not included in the winter count, and 2 new packs were detected after the winter 2010 surveys. Nine radio-collared wolves were mostly loners/disperser while on the air in 2010, and at least 11 pack wolves became dispersers during the year. Four wolves switched pack affiliations with only short intervals of dispersal between the switch. During the year, 18 collared wolves died, and radio signals were lost on 13 wolves. Age and gender of wolves monitored (during most of 2010, or at time of death or signal lost) included 28 adult males, 44 adult females, 5 yearling males, 12 yearling females, 1 pup male, and 1 pup female. At the end of 2010, 60 wolves remained on the air including: 16 adult males, 29 adult females, 3 yearling males, 10 yearling females, 1 pup male, and 1 pup female.
Wolf Mortality
A total of 72 wolves and 3 wolf-dog hybrids were found dead in Wisconsin in 2010, and 2 wolves originally from Wisconsin died in adjacent states (Table 3). The sample of wolves found dead included: 20 adult males, 23 adult females, 3 unknown adults, 4 yearling males, 6 yearling females, 3 pup males, 7 pup females, 3 unknown pups, 1 unknown age & gender, and 2 unknown females (last 2 probably yearlings or adults). Among 16 wolves actively monitored (some of these are preliminary) by the Wisconsin DNR: 6 (38 %) were shot illegally, 2 (12 %) were euthanized for human safety concerns, 2 (12%) were killed by vehicle, 1 (6%) died from disease, 1 (6%) died from unknown natural mortality (old age?), 1 (6%) died from other wolves, and 3 (19%) died from unknown causes. One of the wolves that appeared killed by a vehicle, was also suffering from mange, which may have been a predisposing factor (i.e. less alert and spending more time along roads). Including 2 wolves dying in adjacent states, 18 of 91 radio-collared wolves monitored by WDNR died in 2010 for an overall rough mortality rate of 20%, suggesting relatively low mortality rates.
Among the overall sample of 72 wolves found dead in the state in 2010, mortality included: 14 (19 %) illegal shooting (1 by bow), 1 (1%) trauma from unknown causes, 16 (22 %) euthanized in human safety concerns, 1 (1%) euthanized depredator (originally suspected as hybrid), 26 (36 %) vehicle collisions (1 by train), 1 (1%) euthanized sick animal, 2 (3%) disease (mange), 1 (1%) other wolves, 1 (1%) other natural mortality, and 9 (12%) unknown mortalities. Among the overall sample of dead wolves, at least 81% died from human caused mortality, compared to 62 % of the radio collared sample. The radio-collared sample is probably a less biased assessment of overall mortality affecting wolves, but mainly reflects mortality among adults, and may not be as representative of dispersers living in more marginal habitat across the state.
Wolf Observations and Distribution
Reports of wolf observations that were classified as ?probable? or ?possible? were received from 55 counties in the state, although only single observations were received from 13 counties (Table 4). These reports, from citizens and agency personnel, supplement other wolf survey work, provide early reconnaissance of new wolf occurrence, and provide information on general distribution of wolves across the state, especially lone
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dispersers. These reports do probably also contain some misidentifications of coyotes, wolf-dog hybrids, and dogs as wolves. The 365 reports of wolf observations in 2010 were similar to 2009 (373 reports), 2008 (351 reports), and 2007 (329 reports). Highest report rates for wolf observations were from Price (23), Marinette (22), Ashland (20), Douglas (18), and Bayfield (17) counties.
Wolf Depredation on Domestic Animals and Other Nuisance Problems
Wolf depredation to livestock occurred on 47 farms in 2010, compared to 28 farms in 2009, and exceeds the previous record of 32 farms in 2008 (Table 5a). Total livestock depredation in 2010 included: 63 cattle killed (47 calves), 5 cattle injured, 6 sheep killed (4 lambs), 1 goat injured, and 6 farm deer killed. A total of 25 to 27 packs and 2 to 4 loners/dispersers were involved in depredation on livestock. Twenty-three of the depredating packs were detected in the previous winter and were 13% of the known packs in the state. Four verified cases of wolf harassment or threats to livestock were also recorded during 2010 (Table 5a).
Thirty-four cases of wolf depredations on dogs were detected during 2010, including 14 cases of wolf depredations on pet dogs near homes, and 20 cases of depredations on dogs in hunting and training situations (Table 5b). A total of 24 dogs were killed and 14 were injured by wolves by 21 different packs (12% of packs in the state in 2010) and 1 loner/disperser. Among hunting dogs 19 were killed and 4 were injured (including 1 bird dog), and among pet dogs, 6 were killed and 10 were injured. An injury to a bird hunting dog in Jackson County on 21 September 2010, was the first depredation on a dog in a bird hunting situation ever recorded in Wisconsin. The total kill on dogs by wolves was less than the 25 killed in 2006, but the 14 injured in 2010 exceeded the previous high of 11 in 2009. Rate of wolf depredation on hunting dogs was similar to recent years, but rate of depredation on pet dogs was the highest ever recorded in the state. A total of 5 packs were involved in depredation on both dogs (all pet dogs) and livestock. A total of 31 packs (~17 % of state packs) would have been likely exposed to control actions if wolves had been delisted (packs attacking livestock or pets near homes), and with typical success rate of these controls, wolves would have been removed from about half these packs. No authority for lethal controls, accept in human safety situations, existed for the Wisconsin DNR in 2010.
Nine safety concerns involving 7 packs across 5 counties were documented in 2010 (Table 5c). In two of these situations, levels of habituation were serious enough that WDNR exercised its authority to ?take? wolves that were considered ?demonstrable but not immediate threats to human safety?. In cooperation with USDA-Wildlife Services, 15 wolves and 1 wolf ?dog hybrid were captured and euthanized or shot from a farm in Price County, and a cranberry bog in Jackson County. The Price County pack was also involved in livestock depredation and harassment, and the Jackson County pack had also attacked and threatened dogs. Additionally, a wolf captured and collared from the Price County farm (770M) in spring 2010, was euthanized away from the farm when recaptured in October when it continued to show habituated and aggressive behavior.
Plans for 2011
Monitoring activity as occurred since 1979 will continue, including trapping and collaring wolves in spring and summer (20-30), placing collars on wolves caught by fur trappers (10-15), aerial monitoring of all collared wolves will be done weekly, retrieving and determining cause of death will be performed on wolves that die in the field, snow track surveys will be conducted with agency personnel and volunteers, and collecting wolf observations will continue. Wolf depredations will be investigated by USDA-WS and they will provide advice and assist in deterring wolves from problem areas. Some limited lethal control activity may be permitted through a section 10 permit with USFWS. The USFWS is planning on starting a new delisting program in spring 2011, but it is not likely to be completed until the end of 2011.
Complete report click here
http://dnr.wi.gov/org/land/er/publications/reports/pdfs/ER_report140.pdf?topic=mammals
