9520820 HASTINGS Population biologists have developed models of population growth that are designed to predict the fate of fragmented populations, but these models have not been tested. Such tests require data on the original conditions and the ultimate fates of real fragmented populations. If a set of populations that were fragmented in the past can be identified, and we can use models to predict whether each should be persisting today, a comparison of observed and predicted persistence can determine model reliability. According to fossil evidence, a set of at least 14 populations of pika (a small mammal) was isolated on mountaintops in the Great Basin at the end of the last ice age (about 7500 years ago). Since then, some of these populations have gone extinct. Pika live in a habitat created by freeze-thaw processes. With the retreat of the glaciers and the rising snowline, pika habitat within each mountain range was fragmented. Many aspects of this animal's ecology allow reasonable estimates of the condition of these populations when they were originally fragmented. Thus, models to predict the persistence of these populations can be developed. The proposed research will gather the data necessary to develop these models. The spatial distribution of pika habitat fragments on each mountain range and the movement of individuals between habitat fragments will be calculated. These data will be applied to models similar to those used in current conservation. Natural landscapes are being fragmented by development, often adversely affecting native populations. In order to plan development that it is compatible with the persistence of natural populations, we must be able to reliably predict population persistence under various patterns of habitat fragmentation.
