AN ADAPTIVE MANAGEMENT APPROACH TO CONTROLLING SUBURBAN DEER

We employed an adaptive management approach to initiate a program usin g contraceptives to control growth of a white-tailed deer (Odocoileus virginianus) population in a suburban environment. Demographic data ga thered as part of a 4-year culling effort were used to calibrate the r elationship between population size (N) and sustained yield (SY). We m odeled population dynamics to estimate the numbers of deer necessary t o cull and treat with contraceptives to maintain a stationary populati on. We determined the effort required to achieve and maintain various population goals based on an estimated relationship between effort and N. Preliminary estimates suggested that ecological carrying capacity (K) was 858 deer and maximum sustained yield (MSY) was 124 deer. Numbe rs of deer to be culled to maintain a stationary population were simil ar at corresponding points on either side of MSY (e.g., about 110 deer removed at 257 or 601 deer), but effort was much greater when the pop ulation was on the left arm of the SY parabola (e.g., 545 hrs vs. 1,06 4 hrs to remove 110 deer from N of 257 and 601, respectively). Numbers of females to treat with contraceptives (234 deer) were dissimilar at corresponding points on the SY parabola and higher than numbers to be culled (110 deer) at N of 601 because females were not removed from t he population. Effort to implement contraception alone was greater tha n culling alone because of the increased numbers of females involved, and the necessity for 2 contraceptive treatments (e.g., at N of 429; 3 ,037 and 910 hr to treat and cull deer, respectively). Modeling predic tions were especially sensitive to estimates of nonculling loss in the population and the relationship between N and effort. Future manageme nt actions should incorporate an experimental design to improve these estimates.