seaturtle.org : MTN : ARCHIVES : Sign In

In 1981, one nightly visit to Raccoon Key was conducted and two adult female loggerheads (Caretta caretta) were tagged (G. Williamson, pers. comm.). Both turtles were found on the southeastern portion of the key. Of these, one (tag GA1697) was reported caught by a trawler off Diamond Shoals, North Carolina less than a year later in early March 1982. Keinath (1993) found that three subadult loggerheads over-wintering off the coast of North Carolina (two off Cape Fear, one off Cape Hatteras) made northerly excursions during March and April. Thus, the Raccoon Key turtle (tag GA1697) may have over-wintered near her recapture site. Later, however, a crew member from the same trawler reported this turtle captured in St. Andrews Sound, Georgia in October 1982 (J. Richardson, pers. comm.). Unfortunately, coincidences such as the same trawler catching a single turtle twice (and hundreds of miles apart), although possible, remain highly suspect and should be viewed as questionable.

In 1982, Shoop et al. (1985) investigated the area from Cape Hatteras, North Carolina to the Rio Grande, Texas for sea turtle activity. They, too, reported a dramatic reduction in nesting activity on Raccoon Key which they noted may have resulted in part from a mud flat that developed in 1982 on the ocean side of the island and made beach access difficult for the female turtles. It appears, however, that the observed declines were part of a long-term trend. The following year Frazer (1983a) reported that the Little Cumberland Island, Georgia population was declining by 3% per year during the early 1980's. Little Cumberland Island's population decline continues (National Research Council, 1990).

In 1988, one of us (CRW) checked Raccoon Key for turtle activity in early July. At that time only the northeast beach was surveyed. Five nests, presumably loggerhead, were found. Of these, four appeared to contain a normal complement of eggs for this species (Dodd, 1988, indicated a mean of 120 eggs per nest for Caretta). The fifth nest had apparently been laid and subsequently destroyed much earlier in the season (as evidenced by a large pit obviously dug by raccoons); no egg shells were found. All five nests had apparently been destroyed by raccoons, Procyon lotor. To our knowledge, data were not collected on Raccoon Key from 1988-1994.

On 24 August 1994, a trip was undertaken to the northeastern shore of the key. Although several areas appeared to have had previous turtle activity (i.e., shallow aborted nest cavities and aged body pits), no nesting could be confirmed. On 29 August 1994, the remaining beaches were surveyed for turtle activity. On this date, turtle nests were found on the southeastern portion and, more interestingly, on the northwestern portion of the key. A total of seven nests, six in the southeastern section and one in the northwestern section, were found. Again, as in 1988, all nests had been invaded and completely destroyed by raccoons.

Fluctuations in yearly numbers of turtles and turtle nests are well documented from other nesting beaches in Georgia (Camhi 1993; Richardson et al. 1978) and South Africa (Hughes 1976, 1980). Although nesting activity during the original 1977 aerial survey could have been over~-estimated, comparisons between aerial counts and concurrent ground truth counts conducted on six islands during 1977 showed only a 1.02% difference in combined nesting activities (Hillestad et al. 1997). Also, by comparison, the nest density reported by Richardson et al. (1980) is not greatly different from that reported by us in 1994.

Changes in the beach during the last few years, both offshore and onshore, may account for some of the decline in activity on Raccoon Key. The addition of a substantial amount of shell material on at least the northeastern portion of the beach has made digging a nest cavity much more difficult for female turtles. Also, much of the ocean front beach has been vegetated by large patches of Spartina grass which may interfere with a female's approach. Frazer (1983b) has shown for Little Cumberland Island, Georgia that turtle activity is significantly greater during the periods immediately before and after high tide. If the same is true for Raccoon Key, the mud flat on the ocean side of the island may act as a deterrent only during that part of the tidal cycle when relatively fewer turtles are making landfall.

The contention that physical changes have contributed to reduced nesting at Raccoon Key is supported by the observation that Pine Island to the northeast has received moderate nesting activity since 1988. In 1987 and 1988, Pine Island had nine and seven nests, respectively. However, from 1989 through 1994, Pine Island has averaged 14 nests per year. In addition, Little Wassaw Island (to the north of Raccoon Key) had two nests in 1994 and one nest in 1992, the only nesting known to occur on that island in recent years (Moulis 1994). Further, M. Holliday (pers. comm.) reports a substantial amount of nesting activity along the northern portion of Ossabaw Island to the southeast. Whether this represents a measurable increase in activity for this section of beach is unknown. These records could indicate that neighboring islands may be receiving nests from turtles which can no longer reach suitable nesting areas on Raccoon Key.

Camhi, M. D. 1993. The role of nest site selection in loggerhead sea turtle (Caretta caretta) nest success and sex ratio control. Ph.D Dissertation. Rutgers Univ., New Jersey. 255 pp.

Dodd, C. K., Jr. 1988. Synopsis of the Biological Data on the Loggerhead Sea Turtle Caretta caretta (Linnaeus 1758). USFWS Biol. Rept. 88(14):1-119.

Frazer, N. B. 1983a. Survivorship of adult female loggerhead sea turtles, Caretta caretta, nesting on Little Cumberland Island, Georgia, USA. Herpetologica 39:436-447.

Frazer, N. B. 1983b. Effect of tidal cycles on loggerhead sea turtles (Caretta caretta) emerging from the sea. Copeia 1983:516-519.

Hillestad, H. O., J. I. Richardson and G. K. Williamson. 1977. Incidental capture of sea turtles by shrimp trawlermen in Georgia. Report to the U. S. National Marine Fisheries Service, contract 03-7-042~ 35129. 106 pp.

Hughes, G. R. 1976. Irregular reproductive cycles in the Tongaland loggerhead sea turtle, Caretta caretta L. (Cryptodira: Chelonidae). Zoological Africana 11:285-291.

Hughes, G. R. 1982. Nesting cycles in sea turtles -- typical or atypical? p.81-89 In: Biology and Conservation of Sea Turtles (K. A. Bjorndal, Editor). Smithsonian Institution Press.

Keinath, J. A. 1993. Movements and behavior of wild and headstarted sea turtles. Ph.D Dissertation. Virginia Inst. Mar. Sci., College of William and Mary, Virginia. 206 pp.

Moulis, R. A. 1994. Caretta Research Project Annual Report for Wassaw National Refuge: 1994 Season. Submitted to the U. S. Fish Wildl. Service. Unpubl. 56 pp.

National Research Council. 1990. Decline of the Sea Turtles: Causes and Prevention. National Academy Press. Washington D. C. 259 pp.

Richardson, J. I., T. H. Richardson and M. W. Dix. 1978. Population estimates for nesting female loggerhead sea turtles (Caretta caretta) in the St. Andrew's Sound area of south-eastern Georgia, USA. Fla. Mar. Res. Publ. 33:34-38.

Richardson, J. I., G. K. Williamson and C. L. Groves. 1980. An aerial survey of sea turtle nesting activity in Georgia. Report to the U. S. Fish and Wildlife Service, contract 14- 16-0004-80-053. 48 pp.

Shoop, C. R., C. A. Ruckdeschel and N. B. Thompson. 1985. Sea turtles in the southeast United States: nesting activity as derived from aerial and ground surveys, 1982. Herpetologica 41:252-259.

ROBERT A. MOULIS, 39 Merrydell Drive, Savannah, Georgia 31419 and CHARLES R. WARNOCK, 1 Rivers Bend Court, Savannah, Georgia 31406 USA.