Meeting Abstract
P1.9 Thursday, Jan. 3 Demography of Female Loggerhead Sea Turtles (Caretta caretta) on Blackbeard Island NWR and Estimates for Georgia�s Nesting Population CASON, H. L.*; LEBLANC, A. M.; TUTTLE, J.; DRAKE, K.; BARNARD, D.; ROSTAL, D.; Georgia Southern University; University of Alabama at Birmingham; Georgia Southern University, U.S. Fish & Wildlife Service; Georgia Southern University; U.S. Fish & Wildlife Service; Georgia Southern University hcason@email.georgiasouthern.edu
Female loggerhead sea turtles were studied on Blackbeard NWR beginning in 2001 until the end of the 2007 nesting season. This nesting population is part of the northern subpopulation which is listed as threatened under the Endangered Species Act. The objectives of this project were to monitor the nesting patterns; determine the internesting interval and remigration rate; determine whether recruitment is occurring; and ultimately provide an estimate the nesting female population for Georgia. Efforts are made to protect their nests from depredation and inundation in order to increase hatching success. Number of nests varies between years, with a low of 35 (2004) and a high of 227 (2006). Saturation tagging was used to identify 336 females that nested on Blackbeard from 2001 to 2007. The mean remigration rate is 3.0 years for 53 females observed. The size distribution shows that this nesting population is composed mostly of medium to large adults with little or no recruitment. Evidence for recruitment of primiparous females was assessed by using physical parameters such as wear of marginal scutes; initial scalloping of marginal scutes; and carapace length. Evidence of growth was also examined. Adult females do show signs of indeterminate growth. Growth rates were calculated using mean carapace length and remigration rates in order to determine if all size classes display similar growth rates. Population estimates were also calculated. Based on the 2006 data, we estimate that the female population of Georgia is ~846. These results support the conclusion that the northern subpopulation is still at risk and that further action is required for its recovery.
