areas where they are sympatric with game herds. By culling unhealthy animals, wolves keep game herds healthy. Opponents state that without wolves, prey populations swell unnaturally, unbalancing ecosystems whilst simultaneously sapping wildlife management resources. In the Iberian Peninsula for example, conservationists consider wolves to be beneficial because they keep wild boar populations stable, thus allowing some respite to the endangered capercaillie populations which suffer greatly from boars eating the eggs and nestlings. In Yellowstone National Park, wolves were shown to have a hugely positive effect on general ecological health, and by extension, that of game herds. Game animals in Yellowstone killed off all young, reachable tree saplings, destroying beaver, songbird, insect, fish and amphibian populations, and threatening to starve themselves via overexploitation. Wolves reduced game animal numbers and forced them to be more mobile, allowing more saplings to grow and allowing the populations of aforementioned animals to increase. Proponents for wolf hunting often point out the apparently adverse effects large wolf populations have on game herds. An example occurred in 2008, in which the Alaska Board of Game approved plans calling for department staff to shoot wolves from helicopters on the southern Alaska Peninsula in order to assist the survival of the Southern Alaska Peninsula Caribou Herd. Wolves were believed to be responsible for a dramatic drop in the Southern Alaska Caribou Herd's population, which once numbered up to 10,000 in 1983, only to drop to a population of 600 animals in 2008. Wolf predation was also believed to be responsible for virtually no calves surviving for the two years prior the culling plans, despite a 70% pregnancy rate. In the former Soviet Union, depending on the locality, a single wolf can consume 90 saiga, 50-80 wild boar or an average of 50 domestic or wild caribou annually. A pack of 2-5 wolves will often kill 2 caribou every three days. Further reports from the former Soviet Union indicate that rather than prey on exclusively sick or infirm prey, wolves seem to attack young or pregnant animals far more frequently, regardless of their sanitary state. In the Nenetskij National Okrug, wolves were shown to select pregnant female domestic caribou and calves rather than infirm specimens, with some reports showing that wolves bypassed emaciated, sickly animals in favour of well fed ones. Large numbers of wolves have also been blamed on the decline of critically endangered saiga antelope herds in Central