Gopher Tortoise Survey Handbook.pdf

The gopher tortoise (Gopherus polyphemus) has some legal

protection, Federal or state, in all of the states where they occur. Threats to

the species vary regionally, and it is often desirable to determine in a

statistically acceptable manner whether tortoise populations are being

maintained or are declining. There is currently no reliable information on

the status and trends of populations across the range, although most

studies appear to show that declines are almost universal. Gopher tortoise

surveys may be conducted for different purposes, e.g., detection of tortoise

presence; estimating population size, density, and trends; and temporal

monitoring to assess effects of habitat management or restoration. A

survey’s specific objectives determine its timing and method. Survey and

population monitoring methods have not been standardized. This makes it

difficult to establish reliable gopher tortoise population information

because it is not possible to reliably compare reports among different

studies. This handbook outlines standardized methods for gopher tortoise

surveys, and suggests which methodologies are best applied to each type of

need and habitat setting. The conclusion is that Line Transect Distance

Sampling is the most statistically reliable when accurate measurement of

tortoise population numbers is needed.