Earlier Nesting Contributes to Shorter Nesting Seasons for the Loggerhead Seaturtle, Caretta caretta

• Published in: Journal of herpetology Vol. 40; no. 1; pp. 91 - 94
• Main Authors: Pike, David A, Antworth, Rebecca L, Stiner, John C
• Format: Journal Article
• Language: English
• Published: Society for the Study of Amphibians and Reptiles 01-03-2006
• Subjects: Bird nesting; Caretta caretta; Climate change; ECOLOGY; Female animals; Marine; Nesting sites; Sea surface temperature; Sea turtles; Seashores; Seasons; Temperature dependence; Turtles
• ISSN: 0022-1511; 1937-2418
• DOI: 10.1670/100-05N.1

Evidence is mounting that warming air and sea temperatures are affecting nesting patterns in oviparous species by causing earlier nesting within seasons. The potential fitness consequences of nesting earlier include extended periods of offspring growth and larger clutch sizes. Additionally, the potential for nesting seasons to last longer exists, possibly allowing species that lay multiple clutches within a season to increase the number of clutches produced. To date, no studies have examined consequences of earlier nesting on duration of nesting season in oviparous vertebrates. We demonstrate that warmer sea surface temperatures are related to earlier nesting in the Loggerhead Seaturtle Caretta caretta, and that this response actually decreases, rather than increases, the length of the nesting season. In recent years (1995–2003), nesting became more evenly distributed throughout the season than in earlier years (1989–1994), and the nesting season decreased by approximately 43 days. Female turtles are unlikely to produce additional clutches within a reproductive season in response to this effect because of physiological constraints, and we cannot rule out the hypothesis that female turtles will lay fewer clutches because of a shortened nesting season, leading to reduced fecundity within seasons.