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On the variability of alligator sex ratios

June 16, 2010

Samples of alligators from wild and 'farm' populations exhibited disproportionate sex ratios. Males predominated among young alligators from wild populations, whereas females were much more abundant than males in the farm population, where resources were superabundant. These results and other considerations lead us to hypothesize that environmental factors influence sex determination in alligators. During favorable environmental conditions natural selection is expected to favor a preponderance of the sex whose individuals exhibit the greater environmentally associated variation in relative fitness. We hypothesize that environmentally associated variation in age at sexual maturity of females produces sufficient variation in relative fitness of females to result in selection for low sex ratios during periods of resource abundance.

Citation Information

Publication Year 1980
Title On the variability of alligator sex ratios
Authors J. D. Nichols, R.H. Chabreck
Publication Type Article
Publication Subtype Journal Article
Series Title American Naturalist
Series Number
Index ID 5221578
Record Source USGS Publications Warehouse
USGS Organization Patuxent Wildlife Research Center