PLACE:  171 Durham

SPEAKER:
Kenneth H. Pollock
University of North Carolina

TITLE:
The Design of Large Scale Wildlife Monitoring  Studies

ABSTRACT:

Techniques for estimation of absolute abundance of wildlife populations has received a lot of attention in recent years (See for example Otis et al. 1978; Seber 1982; Pollock et al. 1990; Buckland et al. 1993). The statistical research has been focused on intensive small-scale studies. Recently, however, wildlife biologists have desired to study populations of animals at very large scales for monitoring purposes. Population indices are widely used in these extensive monitoring programs because they are inexpensive compared to estimates of absolute abundance (Lancia et al. 1994). An absolute stringent underlying assumption is that the population index (C) is directly proportional to the population density (D). The proportionality constant is simply the
probability of  “detection “ for animals in the survey. As spatial and temporal comparisons of indices are crucial, it is necessary to also assume that the probability of detection is constant over space and time. Biologists intuitively recognize this when they design rigid protocols for the studies where the indices are collected. Unfortunately, however, biologists have been reluctant to rigorously test the assumption that involves estimating detection probability over space and time. There is an important need for statistical
research on the design and analysis of these complex studies. Some concepts based on actual avian, amphibian, and fish monitoring studies are presented in this paper. We believe that the estimation of detection probability should be built into the monitoring design through a double sampling approach. There would be a large sample of points where an abundance index is obtained. There would also be a subsample of the same points where detection probability is estimated.
 
 

COFFEE: 10:30 a.m., 104 Snedecor