Sea turtle hatchling production from Florida (USA) beaches, 2002-2012, with recommendations for analyzing hatching success

Endangered Species Research

Llewellyn Ehrhart¹  Blair Witherington¹  Beth Brost¹  Anne Meylan¹  Erin Leone¹  Dean Bagley¹ 

关键词: Hatching success;    Hatchling production;    Survivorship;    Caretta;    Chelonia;    Dermochelys;   

DOI  :  10.3354/esr00653

学科分类：动物科学

来源: Inter-Research

【 摘 要 】

ABSTRACT: We measured sea turtle hatchling production on 16 sea turtle nesting beaches (219.6 km) in Florida (USA) from 2002 to 2012. A standard protocol was used to sample 19701 loggerhead Caretta caretta, 3809 green turtle Chelonia mydas, and 664 leatherback Dermochelys coriacea nest contents, representing all Florida nesting beaches. We assessed (1) annual variation in hatching (hatched eggs/total eggs) and emergence (emerged hatchlings/total eggs) successes, (2) annual hatchling production, and (3) sources of egg and hatchling mortality. Emergence success rates were extrapolated to all Florida sea turtle nesting beaches using means weighted by each beach’s nesting contribution. Weighted mean emergence success was 51.6% for loggerheads, 50.0% for green turtles, and 38.7% for leatherbacks. These estimates represent survivorship to the time hatchlings emerge from the nest. The estimated annual mean number of hatchlings produced on Florida beaches during the study period was 3528180 loggerheads (SD = 1155701), 568098 green turtles (SD = 327156), and 33014 leatherbacks (SD = 17574). Beach erosion from storms and nest predation by mammals were the principal identified sources of egg and hatchling mortality. Average emergence success ranged from 38.8 to 65.0% between years and 41.8 to 61.7% between study beaches, suggesting that a single sample year or location would not adequately represent a sea turtle population in demographic analyses of multiple year classes. We provide recommendations for analyzing hatching success and present a method of analysis that allows the inclusion of partially depredated nests. These nests are typically excluded because the original clutch size and the number of eggs removed by predators may not be known.

【 授权许可】

Unknown