Witherington, Blair E. and Llewellyn M. Ehrhart 



Status and Reproductive Characteristics of 

 Green Turtles (Chelonia mydas) Nesting in Florida 



Center for Sea Turtle Research 

 Department of Zoology 

 University of Florida 

 Gainesville, FL 32611 USA 



Department of Biological Sciences 



University of Central Florida 



Orlando, FL, 32816 USA 



From 1973 to 1981, a 40 km stretch of beach north of Cape 

 Canaveral on the east coast of Florida was monitored 

 intermittently for sea turtle nesting activity. Beginning in 

 1981 this effort shifted south, to a 21 km stretch of beach near 

 the town of Melbourne Beach, Florida, and is continuing. On 160 

 occasions at both sites, 91 green turtles were observed The 

 number of nests made by green turtles has been monitored 

 systematically at Melbourne Beach from 1982 to 1987 and has been 

 cyclic, varying between 1.5 and 13.4 nests/km/yr. Nesting 

 numbers appear to be increasing. Though small in comparison to 

 the number of loggerhead turtles that nest at Melbourne Beach, 

 this accounts for a large part of this species' reproductive 

 activity in Florida. Green turtles nest from early June to late 

 September, with peak nesting occurring in July and August. 



The sizes of nesting female green turtles ranged from 83.2 

 to 116.7 cm standard straight-line carapace length (SCL; n = 90, 

 mean = 101.5 cm, SD = 5.83). Total straight-line carapace length 

 (TCL) , used for comparisons with other areas, averaged 102.4 cm 

 (n = 89, SD = 5.61). Body mass ranged from 104.3 to 176.8 kg (n 

 = 15, mean = 136.1 kg, SD = 17.7). The absence of values for 

 variation accompanying size data from Costa Rican green turtles 

 (Carr and Hirth, 1962, mean = 100 cm TCL; Bjorndal 1982, mean = 

 12 6 kg) precludes statistical comparisons. A comparison with 

 green turtles nesting in Surinam (Pritchard 1969; mean = 107 cm 

 TCL) indicates that Florida green turtles are significantly 

 smaller (f test, t statistic adjusted for unequal variances and 

 sample sizes, P<0.01). Growth rates in SCL of adult female green 

 turtles recovered in Florida were small (n = 15, mean = 0.5 

 cm/yr, SD = 0.6). 



Clutch sizes of Florida green turtles ranged from 90 to 

 199 eggs (n = 130, mean = 136 eggs, SD = 21.2). Mean clutch size 

 of Florida green turtles exceeded that of Costa Rican green 

 turtles (K. Bjorndal pers. comm. ; mean = 112 eggs, t' test, 

 P<0.01) and Ascension Island green turtles (Mortimer and Carr, 

 1987; mean = 121 eggs, t' test, P<0.01). Clutch size in Florida 

 green turtles appears similar to that reported for Surinam green 



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