A 21-Year Study of Seasonal and Interspecific Variation of Hatchling Emergence in a Nearctic Freshwater Turtle Community: To Overwinter or Not To Overwinter?

Abstract

Abstract: Hatchling emergence patterns were studied in a community of six species of freshwater turtles in Lancaster County, Pennsylvania, USA, including: Chelydra serpentina, Chrysemys picta, Clemmys guttata, Glyptemys insculpta, Glyptemys muhlenbergii, and Sternotherus odoratus. Data were collected every year from 1965–1985 on estimated date of emergence, carapace length, April–May precipitation, August–September precipitation, annual precipitation, and low temperature and occurrence of precipitation during the 24 h prior to the time of each hatchling detection (n = 806). Chelydra serpentina, Ch. picta, and Cl. guttata hatchlings have a facultative delayed emergence strategy. The other species (G. insculpta, G. muhlenbergii, and S. odoratus) appear to be obligate early emergers, with the exception of one hatchling G. muhlenbergii that delayed emergence. Early emergence occurred in some species every year. However, the majority of hatchlings delayed emergence until the year following oviposition, excep...