Accuracy of Egg Flotation Throughout Incubation to Determine Embryo Age and Incubation Day in Waterbird Nests

The condor

Joshua T. Ackerman¹ 

关键词: age-determination techniques;    egg flotation;    embryo age;    hatching date;    incubation day;    nest age;   

DOI  :  10.1525/cond.2010.090070

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Abstract. Floating bird eggs to estimate their age is a widely used technique, but few studies have examined its accuracy throughout incubation. We assessed egg flotation for estimating hatch date, day of incubation, and the embryo's developmental age in eggs of the American Avocet (Recurvirostra americana), Black-necked Stilt (Himantopus mexicanus), and Forster's Tern (Sterna forsteri). Predicted hatch dates based on egg flotation during our first visit to a nest were highly correlated with actual hatch dates (r = 0.99) and accurate within 2.3 ± 1.7 (SD) days. Age estimates based on flotation were correlated with both day of incubation (r = 0.96) and the embryo's developmental age (r = 0.86) and accurate within 1.3 ± 1.6 days and 1.9 ± 1.6 days, respectively. However, the technique's accuracy varied substantially throughout incubation. Flotation overestimated the embryo's developmental age between 3 and 9 days, underestimated age between 12 and 21 days, and was most accurate between 0 and 3 days and 9 an...

【 授权许可】

CC BY