Premium
Sex Ratio and Nest Temperature in Turtles: Comparing Field and Laboratory Data
Author(s) -
Bull J. J.
Publication year - 1985
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1939163
Subject(s) - nest (protein structural motif) , sex ratio , avian clutch size , ecology , incubation , biology , zoology , reproduction , demography , population , biochemistry , sociology
Sex is determined by incubation temperature in many reptiles, but precise quantifications of these effects have been obtained only in the laboratory. Here, temperatures and sex ratios were studied from 75 clutches of map turtles incubated in their natural nests. Clutch sex ratio showed a clear association with each of the two measures of nest temperatures studied: (1) hours per day above 30° or 32°C, and (2) the mean and variance of nest temperature. The best associations with sex ratio were obtained from temperatures experienced during the 4th through 7th wk of development and from temperatures during July. Results from this study were similar in several respects to results from previous laboratory studies on sex determination, despite the fact that natural incubation entails fluctuating temperatures and other environmental effects not incorporated in most laboratory studies.