Estimating intemal egg volumes from linear dimensions: isomorphy in eggs belonging to the family Ardeidae

Resum

Estimating internal egg volumes from linear dirnensions: isomorphy in eggs belonging to the family Ardeidae
Recently laid (less than 24h) eggs of Ardeola ralloides, Bubulcus ibis, Egretta garzetta and Ardea purpurea were collected in the Ebro Delta during the breeding seasons of 1988-1990. Once measured (length and breadth) and voided, they were refilled with 70% alcohol using a buret to determine intemal volumes. Interna1 volumes were related to linear dimensions (L x B²) through a regression analysis both for each species separately and for all species together. Intemal volume constant (Kv,) for all species is 0.4945 and the eggs of all the species are isomorphous, i.e. their volume constants are very similar.