Analysis of harvest and effort data for wild populations in fluctuating environments

An approach is developed for analysis of harvest and effort data that uses a surplus production model modified for analyses in a fluctuating environment, and that maximizes harvest with as small an effect on the intrinsic rate of increase as possible. Harvest and hunter effort data that are suitable for analysis with a surplus production model have been collected for several wildlife species for many years. I used data for the mallard duck, lesser scaup duck, white-tailed deer, and black bear. The parameters were estimated with harvest and hunter data using non-linear least squares. For each species both the relation between the maximum sustainable harvest (MSH) and effort and a more conservative optimal level of harvest and effort were obtained under a range of environmental conditions. The mallard duck and white-tailed deer were both over harvested for short periods in the past, but only the black bear population appears over harvested today.