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Egg morphometrics and egg shape coefficients for White-faced Ibis (Plegadis chihi)

March 1, 2021

Egg size is a useful metric for maternal investment, offspring quality, and contaminant studies. Yet these values and the egg shape coefficients required to estimate egg size are not available for many species, including White-faced-Ibis (Plegadis chihi). We provide egg morphometrics derived from 319 White-faced Ibis eggs sampled at Bear River Migratory Bird Refuge, Great Salt Lake, Utah, from 2010 to 2012. Measured egg length (mean ± SD) was 51.20 ± 1.99 mm, egg width was 36.08 ± 1.15 mm, and whole egg mass was 34.1 ± 3.3 g. Estimated whole egg volume was 34.63 ± 3.73 cm3 and estimated egg shape coefficients were 0.507 for Kv (whole egg and egg contents), 0.547 for Kw (whole egg), and 0.524 for Kw (egg contents only). In addition, we documented expected declines in egg mass over time due to incubation (–0.22 g/d) and desiccation during storage (–0.03 g/d), that should be accounted for prior to analyses that use egg mass of freshly laid eggs.

Citation Information

Publication Year 2021
Title Egg morphometrics and egg shape coefficients for White-faced Ibis (Plegadis chihi)
DOI 10.1676/21-00057
Authors Mark P. Herzog, Joshua T. Ackerman, C. Alex Hartman
Publication Type Article
Publication Subtype Journal Article
Series Title The Wilson Journal of Ornithology
Index ID 70227888
Record Source USGS Publications Warehouse
USGS Organization Western Ecological Research Center