Genetic Studies and Population Management: Anegada Iguanas
In 2004, the divisions of Applied Conservation and Genetics at the San San Diego Zoo's CRES received a grant from the Institute of Museum and Library Services to conduct a collaborative project on the conservation genetics of the critically endangered Anegada iguana Cyclura pinguis. The primary objective of this project was to carry out a comprehensive genetic analysis of the captive colleciton of Anegada iguanas at the San Diego Zoo and compare this with data from the wild to obtain the information needed to implement a sound captive-breeding program.
A DNA microsatellite library was obtained and screened for candidate loci, which were in turn screened for polymorphism. Genotypes for 23 loci were then obtained from three cohorts of individuals: captive potential founders in the Zoo's collection, randomly related wild individuals, and known clutchmates from the wild. Using a statistical analysis based on maximum likelihood estimations, three separate pairs of related individuals within the captive cohort were identified.
This information is now being used to design a captive-management plan that will maximize genetic diversity in the Zoo's growing captive collection. In addition, this genetic work has shown that the wild population, although critically endangered with a remaining estimated wild population of 200 individuals, does not appear to have recently experienced a high degree of inbreeding. Thus, the information gained through this project will also be valuable for monitoring the genetic health of the wild population over time. The natural history traits and behavioral ecology of these iguanas that have evolved in their limited habitat contribute to their persistence and impact their genetic structure (i.e., inbreeding avoidance). Further studies will benefit from the genetic tools and insights already developed in this project.
In addition, the project involved an education component, with activities taking palce on Anegada Island and at the San Diego Zoo. On Anegada, surveys were utilzied to assess local attitudesand awareness, and an informational campaign was launched to raise support and awareness for iguana conservation. At the Zoo, signage was produced for the Anegada iguana exhibit highlighting the role of genetic research in population management, and public awareness was raised through educational presentations and the Zoo's Web site.
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Stories from the Field: Anegada Iguanas: Buddies or Siblings?
