Morphological responses of white-tailed deer to a severe population reduction

Abstract

We document responses, in terms of mass, hind-foot length, and antler beam diameter, of white-tailed deer (Odocoileus virginianus borealis) to an approximate 85% population reduction achieved by means of a series of public hunts in Long Point National Wildlife Area (LPNWA), Lake Erie, Ontario. Dressed weights and yearling antler beam diameters of LPNWA deer are among the lowest on record for this subspecies. Notable increases between 1989 and 1990 and in 1994 were common, especially in younger animals. Most significantly (P <<= 0.05), from 1989 to 1994, mean mass of male fawns increased by 44%, that of yearling males by 96%, and that of 2.5-year-old bucks by 75%. Significant increases in mean hind-foot length were also noted in male and female fawns and 2.5-year-old bucks. Antler beam diameters increased by 93% in yearlings and 35% in 2.5-year-old bucks between 1989 and 1994. The significant and immediate responses to decreased density and competition demonstrate that the herd was under extreme environmental stress and show the exceptional resiliency of this species in withstanding severe environmental pressure. Long Point deer are not genetically smaller than adjacent mainland deer as some had thought, but their growth has been restricted by environmental conditions.