Housing development is often intermixed within natural land cover, creating coupled humannatural systems that benefit some species, while eliminating critical habitat for others. As carnivore populations recover and expand in North America, understanding how populations may recolonize human-dominated landscapes is an important goal for conservation. We empirically test whether a population of American black bear (Ursus americanus) recolonizing a developed landscape is responding to land cover, housing density, or the amount of intermixture between forest and housing as quantified by the Wildland Urban Interface. Housing density was the most supported spatially explicit mark-recapture model and indicated that bear density was highest among exurban housing densities. Mean estimated bear density in exurban areas (6-49 houses/km 2) was 0.18 individuals/km 2 compared to 0.12 individuals/km 2 in rural areas (< 6 houses/km 2). Bear densities also declined to zero as development approached 50 houses/km 2. We also tested for differences in sex ratio between more and less intensely developed areas, using hybrid mixture models. Sex ratios were significantly more male-biased in areas of higher housing density. Elevated bear densities provide evidence that exurban land-use can facilitate recolonization of black bears, yet high housing density may also limit the recovery of bear populations. Explicit relationships between land-use and bear density will allow managers to anticipate future population distribution, and areas where bears and people may come into frequent contact.
Lethal control alone has not proven entirely effective in reducing gray wolf (Canis lupus) depredations in chronic problem areas. Opponents of lethal control argue that more emphasis should be placed on integrating nonlethal strategies into current management. However, few evaluations have tested the effectiveness of nonlethal options. We compared behavior patterns in terms of frequency and duration of bait station visits for 5 wolves fitted with shock collars to 5 control animals inhabiting wolf pack territories in northern Wisconsin during summers of 2003 and 2004. Shock collared wolves spent less time and made fewer visits to bait station zones than did control animals. During and after shocking, wolves shifted 0.7 km away from the bait station zone. Although active shocking did restrict wolf access, which could be useful in controlling wolf depredations during a limited time period, conditioning was not clearly demonstrated once shocking ceased. The effect of shock collar design and operation on long‐term conditioning and shock‐conditioned wolves on pack behavior needs further study. If long‐term conditioning is possible, shock collars could be used by wildlife managers as a nonlethal wolf management method in chronic problem areas where lethal control has proven ineffective.
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