MEPS 324:287-292 (2006)  -  doi:10.3354/meps324287

Effects of transients on estimating survival and population growth in juvenile loggerhead turtles

Christopher R. Sasso1,*, Joanne Braun-McNeill2, Larisa Avens2, Sheryan P. Epperly1

1National Marine Fisheries Service, Southeast Fisheries Science Center, 75 Virginia Beach Drive Miami, Florida 33149, USA
2National Marine Fisheries Service Southeast Fisheries Science Center, 101 Pivers Island Road, Beaufort, North Carolina 28516, USA

ABSTRACT: Population growth and annual survival of juvenile loggerhead turtles Caretta caretta were investigated in North Carolina using mark-recapture techniques. Lack of fit of the models employed caused us to reject the obtained estimates and led us to suspect that many loggerhead turtles were transient in the study area. We estimated apparent survival and the proportions of residents and transients. Transients represented approximately 75% of newly captured individuals captured at our study site. When transients were taken into account, apparent survival of residents increased from between 0.36 and 0.74 to 0.81. Our study highlights the need to consider the presence of transients when interpreting the results of loggerhead monitoring studies.


KEY WORDS: Mark-recapture · North Carolina · Pound nets · Sea turtles


Full text in pdf format