Field Test of Gopher Tortoise (Gopherus Polyphemus) Population Estimation Techniques; Final rept

摘要

The Army is very concerned about the preservation of Threatened and Endangered Species (TES) that make their home on Army training lands. The gopher tortoise (Gopherus polyphemus) is one species that the Army is particularly concerned about. To ensure that the Army is able to execute its training mission requirements while mitigating adverse impacts to the gopher tortoise, installation natural resource managers have to track species abundance in a consistent and statistically comparable manner from year to year. This requires that the Army exercise great diligence in identifying methods to derive species abundance that can meet all levels of terrain and vegetative conditions present in a species habitat. The objective of this research was to conduct field tests to evaluate the line transect, total count, sample count, and double observer methods for estimating gopher tortoise burrow abundance and compare them in respect to efficacy, precision, and cost of application. This report contains a discussion of the field tests and recommendations for installation natural resource managers.