Conservation of island endemics
Why is it important?
Disjunct, isolated populations present a special challenge for environmental managers. The restricted distribution and isolation of island endemics, especially those with sensitive life history traits (long-lived, low reproductive rate), places them at risk for the detrimental effects of genetic drift and reduced genetic variation. However, this isolation often leads to unique phenotypes or genetic diversity of conservation interest to management agencies. In collaboration with multiple academic institutions, the Bureau of Land Management (BLM), and the United States Navy, we are investigating genetic diversity and effective population size, gene flow and population substructure, and population stability in several island systems.
Island Night Lizards, San Clemente Island, CA
The Island Night Lizard (Xantusia riversiana) is a large, long-lived lizard endemic to three of the Channel Islands off the coast of Southern California. The largest island inhabited by X. riversiana is San Clemente Island, which is managed by the United States Navy.
In collaboration with Bill Mautz (UH Hilo) and the US Navy, we are investigating genetic diversity and effective population size, gene flow and population substructure, and population stability of X. riversiana to help design a management plan for the San Clemente Island population.
Desert Night Lizards, Panoche Hills and Pinnacles National Monument, CA
There are two isolated populations of Desert Night Lizards (Xantusia vigilis) about 150 miles northwest of the species' main range in the Joshua trees (Yucca brevifolia) of the Mojave Desert: one population is found in isolated outcrops of Hesperoyucca whipplei in the Panoche Hills and another in Gray Pine (Pinus sabiniana) within Pinnacles National Monument. Due to complete dependence on host plants for shelter, these populations are further fragmented across patchy, south-facing hillsides suitable for plant growth.
In collaboration with Mike Westphal and the Bureau of Land Management, we are investigating genetic diversity and effective population size, gene flow and population substructure, and population stability of X. vigilis in both populations. Additionally, we are collaborating on a larger project comparing these results to the population genetics of both the host plant Hesperoyucca and the plant’s obligate pollinator, the yucca moth (Tegeticula).
