Gopher Tortoise Survey Handbook
Abstract
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2009
- Accession Number
- ADA522655
Entities
People
- Harold E. Balbach
- Jonathan Stober
- Lora S. Smith
- William D. Meyer
Organizations
- Engineer Research and Development Center