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E. K. Harper

Publications and source records attributed to E. K. Harper.

6 recordsLinked to original sources
USGS2010

Effectiveness of lethal, directed wolf-depredation control in Minnesota

Wolf (Canis lupus) depredations on livestock in Minnesota, USA, are an economic problem for many livestock producers, and depredating wolves are lethally controlled. We sought to determine the effectiveness of lethal control through the analysis of data from 923 government-verified wolf depredations from 1979 to 1998. We analyzed the data by 1) assessing the correlations between the number of wolves killed in response to depredations with number of depredations the following year at state and local levels, and 2) the time to the next depredation. No analysis indicated that trapping wolves substantially reduced the following year's depredations at state or local levels. However, more specific analyses indicated that in certain situations, killing wolves was more effective than no action (i.e., not trapping). For example, trapping and killing adult males decreased the re-depredation risk. At sheep farms, killing wolves was generally effective. Attempting to trap, regardless of the results, seemed more effective at reducing depredations than not trapping, suggesting that mere human activity near depredation sites might deter future depredations.

Journal of Wildlife Management↗
USGS2005

Causes of wolf depredation increase in Minnesota from 1979-1998

Wolf ( Canis lupus ) depredations on livestock in Minnesota have been increasing over the last 20 years. A major explanation cited for this increase is wolf range expansion, but no studies have tested this explanation. Additional reasons could include 1) wolf colonization of new areas within long-existing wolf range, 2) learning by wolves in established range, and 3) increased wolf density. We did not assess increasing wolf density as a factor because estimated wolf density in Minnesota has not increased. To assess how each of the other factors might have affected depredations, we created and analyzed a database of Minnesota's 923 verified depredations at 435 farms. We graphed the numbers of verified depredations and the number of farms with verified depredations to assess temporal trends and used ArcView GIS software to assess spatial relationships of the depredations. All 3 factors tested (colonization, range expansion, and learning) seemed to have contributed to wolf depredation increase. However, the proportion of depredations occurring due to wolf range expansion increased from 20% in 1989 to 48% in 1998.

Minnesota↗
USGS2002

Differential use of a wolf, Canis lupus, pack territory edge and core

Based on 418 radio-locations of a Minnesota wolf pack, wolves were found at significantly fewer locations per area in the outer 2 km of the territory than in the core. This finding supports an hypothesis that buffer zones exist between pack territories and may explain why prey survive longer there.

Canadian Field-Naturalist↗
USGS2002

Differential use of a Wolf, Canis lupus, pack territory edge and core

Based on 418 radio-locations of a Minnesota Wolf pack, Wolves were found at significantly fewer locations per area in the outer 2 km of the territory than in the core. This finding supports an hypothesis that buffer zones exist between pack territories and may explain why prey survive longer there.

Canadian Field-Naturalist↗
USGS2000

Assessing factors that may predispose Minnesota farms to wolf predation on cattle

Wolf (Canis lupus) depredations on livestock cause considerable conflict and expense in Minnesota. Furthermore, claims are made that such depredations are fostered by the type of animal husbandry practiced. Thus, we tried to detect factors that might predispose farms in Minnesota to wolf depredations. We compared results of interviews with 41 cattle farmers experiencing chronic cattle losses to wolves (chronic farms) with results from 41 nearby matched farms with no wolf losses to determine farm characteristics or husbandry practices that differed and that therefore might have affected wolf depredations. We also used a Geographic Information System (GIS) to detect any habitat differences between the 2 types of farms. We found no differences between chronic and matched farms in the 11 farm characteristics and management practices that we surveyed, except that farms with chronic losses were larger, had more cattle, and had herds farther from human dwellings. Habitat types were the same around farms with and without losses. The role of proper carcass disposal as a possible factor predisposing farms to wolf depredations remains unclear

Wildlife Society Bulletin↗