Large-scale translocation strategies for reintroducing red-cockaded woodpeckers
Translocation of wild birds is a potential conservation strategy for the endangered red-cockaded woodpecker (Picoides borealis). We developed and tested 8 large-scale translocation strategy models for a regional red-cockaded woodpecker reintroduction program. The purpose of the reintroduction program is to increase the number of red-cockaded woodpeckers by moving subadult birds from large populations to smaller populations that are unlikely to increase on their own. A major problem in implementing the program is determining where birds will be moved because the larger donor populations cannot supply enough birds for all small recipient populations each year. Our goals were to develop translocation strategies and model which ones would (1) result in the most groups of woodpeckers in a given amount of time; (2) most quickly reach the goal of at least 30 groups of woodpeckers in every population; and (3) result in the fewest population extinctions. We developed lump-sum strategies that moved all the translocated birds to 1 population each year, and partitioning strategies that divided the birds among several populations every year. In our simulations, the lump-sum strategies resulted in the most woodpeckers for the overall program and the highest number of population extinctions. Partitioning strategies had the lowest population extinction rate buy produced the lowest rate of increase in the number of woodpecker groups. The model that partitioned birds to the 6 largest recipient populations with fewer than 30 groups was the best overall strategy for meeting our goals because it reached 30 groups in every population the fastest, produced many birds, and had only a moderate population extinction rate. We suggest that adhering to a single strategy that meets the goals of the participants should simplify the program and reduce its cost.