MANAGEMENT OPTIONS FOR PRESERVING GENETIC DIVERSITY - REINTRODUCTION OF GUAM RAILS TO THE WILD

Abstract: Population management programs recognize the importance of managing genetic diversity in species that are candidates for eventual reintroduction to natural habitats. The planned 1989 release of captive‐born Guam rails (Rallus owstoni), extinct in the wild since 1986, to the Northern Mariana island of Rota provides an opportunity to evaluate various management options for selecting breeders to produce young rails for release. Six options were compared to determine which one best replicated genetic diversity in the original captive founder population. Heterozygosity, allelic dimity, founder contribution, and founder genome equivalents were used as indicators of genetic diversity. Option 1: Randomly choose adults for breeding. Option 2: Choose the most fecund captive breeders. Option 3: Use allozyme data to choose parents that will produce the most genetically diverse chicks. Option 4: Choose pairs to equalize founder contribution in the population. Option 5: Choose pairs to maximize allelic diversity. Option 6: Choose pairs to maximize founder genome equivalents. Genetic management options based on pedigree analysis (#4, 5, 6) produced the most genetically diverse release populations for Rota. Managing founder genome equivalents produced a balance between equalizing founder contribution and maximizing allelic diversity, and provided the most genetically diverse population. Randomly selecting breeding pain, choosing the best captive breeding stock, or managing by allozyme data resulted in substantially reduced genetic diversity. Results illustrate that some of the most common approaches to population management or population reintroduction may produce significant loss of genetic diversity, whereas certain genetic management options may actually increase genetic diversity over current population levels. Copyright © 1990, Wiley Blackwell. All rights reserved