Predator vs prey lee martin2/29/2024 ![]() However, the change was greater than in a smaller sized herd in an area without wolf culling, where the calf:cow ratio declined (before: 15.8:100 after: 11.5:100). Between 1992-1993 (before the wolf cull) and 1994-1995 (after the cull), the increase in calf:cow ratio within the cull area (before: 7.4:100 after: 21.5:100) was no greater than in a similar sized herd in an area without wolf culling (before: 11.2:100 after: 19.5:100). 2004) found that wolf Canis lupus culling did not increase calf survival or population size of caribou Rangifer tarandus. Annales Zoologici Fennici, 36, 139-148.Ī controlled, before-and-after study in 1990–2000 in alpine tundra and subalpine shrubland in Alaska, USA (Valkenburg et al. (1999) Impact of predator removal on predator and mountain hare populations in Finland. Referenced paper Kauhala K., Helle P., Helle E. ![]() Hares were monitored by snow track counts, annually from 15 January to 15 March, in 1993–1998. Predator removal, carried out by hunters during normal hunting seasons, commenced in August 1993, targeting red fox Vulpes vulpes, pine marten Martes martes, stoat Mustela ermine and raccoon dog Nyctereutes procyonoides. In each of three areas, a predator removal and predator protection site were established, ≥5 km apart. Data are presented as track count indices. In the third area, hare numbers declined each year in predator removal sites but increased in two of five years in protection sites. In two of three areas, mountain hare numbers increased in both predator removal and predator protection sites, with the rate of increase being higher in the predator protection site than the removal site in one of those areas. 1999) found that removing predators did not increase numbers of mountain hares Lepus timidus. Supporting evidence from individual studiesĪ replicated, paired sites, controlled study in 1993–1998 of boreal forest in three areas in Finland (Kauhala et al. ![]() The other study found mixed results with increases in white-tailed deer calf survival in some but not all years with predator control. ![]() Two studies found that moose calf survival and woodland caribou calf survival increased with predator control. Survival (5 studies): Two of five before-and-after studies (including two controlled studies and one replicated study), in the USA, Canada and the USA and Canada combined, found that controlling predators did not increase survival of caribou calves, or of calf or adult female caribou.However, one of these studies also found that there was no change in breeding productivity of mule deer. Reproductive success (2 studies): Two replicated, before-and-after studies (one also controlled), in the USA, found that predator removal was associated with increased breeding productivity of white-tailed deer and less of a productivity decline in pronghorns.The other three studies found that removing predators did not increase mountain hare, caribou or desert bighorn sheep abundance. One of these studies also found that mule deer abundance did not increase. Abundance (6 studies): Three of six studies (including three controlled, one before-and-after and one replicated, paired sites study), in Finland Portugal, Mexico and the USA, found that removing predators increased abundances of pronghorns, moose and European rabbits and Iberian hares. ![]() Seven studies were in North America, one was in Finland, one in Portugal and one in Mexico.
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