Brown Noddy (Anous stolidus) Science Article 4
Flotation characteristics of birds’ eggs are commonly used to estimate their age. Schreiber (1970) and Hays and LeCroy (1971) have recently attempted to quantify the relationship between the appearance (degree of emergence and position) larid eggs placed in water and the age of the eggs.
William Y. Brown, The AUK, vol. 93