Gopher
tortoise burrow surveys:
External characteristics, burrow cameras, and truth
Rebecca B. Smith1, Tracey D. Tuberville2, Angy L.
Chambers3, Kris M. Herpich4, Joan E. Berish5
1 Dynamac Corporation, Mail Code DYN-1l, Kennedy Space Center,
Florida, 32899, U.S.A. e-mail: Rebecca.Smith-l @ksc.nasa.gov
2 Savannah River Ecology Laboratory, P.O. Drawer E, Aiken,
South Carolina, 29802, U.S.A.
3 45th Space Wing Environmental Flight, 45CES/CEVT, Patrick
Air Force Base, Florida, 32925, U.S.A.
4 Comprehensive Health Services, CHS-22, Kennedy Space Center,
Florida, 32899, U.S.A.
5 Florida Fish and Wildlife Conservation Commission, 4005 S.
Main St., Gainesville, Florida, 32601, U.S.A.
Abstract. The gopher tortoise (Gopherus polyphemus)
occupies the southeastern Coastal Plain of the United States where it
digs burrows in upland habitats. Two burrow survey techniques commonly
used to estimate tortoise population size (classification of burrows based
on external characteristics and surveying burrow contents with a burrow
camera) were tested to determine accuracy and subjectivity among researchers.
Accuracy of both methods was verified by excavating the burrows to detennine
if tortoises were present. Classification of burrows based on external
characteristics was found to be highly subjective, related to the researchers'
prior gopher tortoise experience, and unrelated to familiarity with the
landscape. Burrow camera surveys were accurate, but should be used with
caution as mistakes can be costly. Inadequacies in the currently accepted
burrow survey methods are discussed and suggestions for improvements are
made.
Key words: Burrow classification; burrow occupancy; burrows;
gopher tortoise; Gopherus polyphemus; protected species; surveying
errors; survey methods.
SREL Reprint #2821
Smith, R. B., T. D. Tuberville, A. L. Chambers, K. M. Herpich and J. E. Berish. 2005. Gopher tortoise burrow surveys: External characteristics, burrow cameras, and truth. Applied Herpetology 2:161-170.
