ACCURACY OF EGG FLOTATION THROUGHOUT INCUBATION TO DETERMINE EMBRYO AGE AND INCUBATION DAY IN WATERBIRD NESTS

被引:36
作者
Ackerman, Joshua T. [1 ]
Eagles-Smith, Collin A. [1 ]
机构
[1] Univ Calif Davis, US Geol Survey, Western Ecol Res Ctr, Davis Field Stn, Davis, CA 95616 USA
来源
CONDOR | 2010年 / 112卷 / 03期
关键词
age-determination techniques; egg flotation; embryo age; hatching date; incubation day; nest age; CANADA GOOSE NESTS; SAN-FRANCISCO BAY; DABBLING DUCKS; STAGE; SURVIVAL; HATCHABILITY; NEGLECT; CHICKS; LENGTH; DATE;
D O I
10.1525/cond.2010.090070
中图分类号
Q95 [动物学];
学科分类号
071002 ;
摘要
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 and 12 days. Age estimates based on egg flotation were generally accurate within 3 days until day 15 but later in incubation were biased progressively lower. Egg flotation was inaccurate and overestimated embryo age in abandoned nests (mean error: 7.5 +/- 6.0 days). The embryo's developmental age and day of incubation were highly correlated (r = 0.94), differed by 2.1 +/- 1.6 days, and resulted in similar assessments of the egg-flotation technique. Floating every egg in the clutch and refloating eggs at subsequent visits to a nest can refine age estimates.
引用
收藏
页码:438 / 446
页数:9
相关论文
共 41 条
[1]   Survival of postfledging Forster's terns in relation to mercury exposure in San Francisco Bay [J].
Ackerman, Joshua T. ;
Eagles-Smith, Collin A. ;
Takekawa, John Y. ;
Iverson, Samuel A. .
ECOTOXICOLOGY, 2008, 17 (08) :789-801
[2]   Mercury contamination and effects on survival of American avocet and black-necked stilt chicks in San Francisco Bay [J].
Ackerman, Joshua T. ;
Takekawa, John Y. ;
Eagles-Smith, Collin A. ;
Iverso, Samuel A. .
ECOTOXICOLOGY, 2008, 17 (02) :103-116
[3]   Integrating Toxicity Risk in Bird Eggs and Chicks: Using Chick Down Feathers To Estimate Mercury Concentrations in Eggs [J].
Ackerman, Joshua T. ;
Eagles-Smith, Collin A. .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2009, 43 (06) :2166-2172
[4]  
ALBERICO JAR, 1995, WILDLIFE SOC B, V23, P212
[5]  
[Anonymous], BIRDS N AM
[6]  
[Anonymous], BIRDS N AM
[7]  
AR A, 1980, AM ZOOL, V20, P373
[8]   EMBRYO METABOLISM AND EGG NEGLECT IN CASSIN AUKLETS [J].
ASTHEIMER, LB .
CONDOR, 1991, 93 (03) :486-495
[9]   PHOTOGRAPHIC INDEX FOR AGING MALLARD EMBRYOS [J].
CALDWELL, PJ ;
SNART, AE .
JOURNAL OF WILDLIFE MANAGEMENT, 1974, 38 (02) :298-301
[10]  
CARROLL JP, 1988, WILDLIFE SOC B, V16, P327