Management of indigenous North American deer at the end of the 20th century in relation to large predators and primary production.

Abstract

Five deer species occupy North America: caribou (3.6 x 10(6) individuals), moose (1.1 x 10(6)), white-tailed deer (28.5 x 10(6)), mule deer (5.0 x 10(6)) and wapiti (1.1 x 10(6)). Caribou characterise the north of the boreal forest and the tundra, whereas moose dominate in coniferous and mixed forests growing further south. White-tailed deer are typical of the deciduous forests of the east while mule deer replace them in the mountainous terrain of the west. Wapiti possess the smallest range, mostly adjacent to the prairies to the west. The two large obligate carnivores preying on deer show a reduced distribution: wolves are almost restricted to Canada, and cougar to the mule deer range. We determined the current status of each species with the help of a questionnaire mailed to all jurisdictions harbouring deer. Most reports of threatened populations concerned caribou whereas many jurisdictions declared overabundance of white-tailed deer and wapiti. Hunting was allowed for all species when they abounded in a jurisdiction. Hunters harvested annually 7.0 x 10(6) deer on the continent, 87% being white-tailed deer. The two species that caused most conflicts with humans had the highest harvest rate: 16-17%. In terms of biomass, white-tailed deer and wapiti yielded the highest harvests, with 55 and 39 kg x km-2 of range, respectively. The average standing biomass of deer in winter ranged between 28 kg x km-2 in Nevada to 901 kg x km-2 in Indiana. The lowest standing biomasses occurred in the boreal forest (predators), in the prairies (agriculture) and in the south-west (aridity), and the highest ones in the south-east, where only white-tailed deer is present. The current abundance of deer in North America parallels, in general, the primary production of the landscape (r2 = 0.38; P < 0.0001), but predators and human activity modify this pattern.