Dramatic reduction in predation on marine turtle nests through improved predator monitoring and management

Richard M. Engeman a1c1, R. Erik Martin a2, Henry T. Smith a3, John Woolard a4, Carrie K. Crady a2, Stephanie A. Shwiff a1, Bernice Constantin a4, Margo Stahl a5 and John Griner a6
a1 National Wildlife Research Center, 4101 LaPorte Ave, Fort Collins, CO 80521-2154, USA.
a2 Ecological Associates, Inc., P.O. Box 405, Jensen Beach, FL 34958, USA.
a3 Florida Department of Environmental Protection, Florida Park Service, 13798 S.E. Federal Highway, Hobe Sound, FL 33455, USA.
a4 USDA/APHIS/Wildlife Services, 2820 East University Ave., Gainesville, FL 32641, USA.
a5 Hobe Sound NWR, 13640 S.E. Federal Hwy, Hobe Sound, FL 33455, USA.
a6 St. Lucie Inlet Preserve State Park, 16450 S.E. Federal Highway, Hobe Sound, FL 33455, USA.

Article author query
engeman rm   [PubMed][Google Scholar] 
martin re   [PubMed][Google Scholar] 
smith ht   [PubMed][Google Scholar] 
woolard j   [PubMed][Google Scholar] 
crady ck   [PubMed][Google Scholar] 
shwiff sa   [PubMed][Google Scholar] 
constantin b   [PubMed][Google Scholar] 
stahl m   [PubMed][Google Scholar] 
griner j   [PubMed][Google Scholar] 


We describe improvements to monitoring/indexing methodology for predators of marine turtle nests on the east coast of Florida, and the resulting marine turtle conservation implications from integrating the methodology into predator management. A strip transect from dune line to the shore improved an already successful design for monitoring raccoons, and was also sensitive for armadillos. The data were integrated into predator management operations to effectively and efficiently remove the species responsible for turtle nest predation. Tracking plot data also served to validate predator patterns of behavior relative to turtle nesting and improve prospects for preventive predator management strategies. Perhaps the most important finding is that predation at a beach historically suffering nearly complete losses (95%) of marine turtle nests had nest predation reduced to nominal levels (9.4%). For 2002 this predation level represents an estimated 69,000 additional hatchling turtles produced over historical predation rates, and 16,700 additional hatchlings over the previous lowest predation rate.

(Received April 15 2004)
(Revised October 19 2004)
(Accepted December 17 2004)

Key Words: Armadillo; endangered species; Florida; marine turtle; population index; predator management; raccoon.

c1 Correspondence: National Wildlife Research Center, 4101 LaPorte Ave, Fort Collins, CO 80521-2154, USA. E-mail richard.m.engeman@aphis.usda.gov