The Effects of Climate on Annual Variation in Reproductive Output in Snapping Turtles (Chelydra serpentina).

Reptiles are highly dependent on climatic patterns to regulate their behavior and physiology, and studies of the effects of climate on the biology of organisms are increasingly important given expected climate change. Our study examined the effects of climate variation over 15 of the 26 years between 1990 and 2015 on the reproductive output of the Common Snapping Turtle (Chelydra serpentina (L., 1758)). Egg mass, clutch size and clutch mass (relative to body size) were significantly higher in years following warmer temperatures in September and October of the year before reproduction, but not related to temperatures in April and May just before reproduction. Of the above life history traits, egg mass varied the least across years, and after warm autumns small turtles (225-285 mm carapace length) increased clutch mass by increasing clutch size but not egg size. In contrast, under the same conditions, large turtles increased clutch mass by increasing egg mass but not clutch size. Our data suggest optimal egg size may vary with female size. Climate change may already have impacted reproductive output in snapping turtles at the site because temperatures during September and October have increased about 0.5 째C each decade for the last 45 years.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author