The breeding biology of the white-chinned petrel Procellaria aequinoctialis at South Georgia

Aspects of the breeding biology of the whitc-chinned petrel Procellaria aequinoctialis were studied at South Georgia. Laying, hatching and fledging dates, together with egg and adult measurements, rate of weight loss of eggs and incubating adults and data on the duration of incubation shifts were recorded. Chick growth in weight, tarsus length, culmen length and wing length from hatching to fledging was followed in detail and breeding success and causes of mortality documented. Comparisons are made with other populations of the species, other members of the genus Procellaria and other Procellariiformes. Despite being the largest burrow-nesting petrel in the world, P. aequinoctialis conforms well to the overall relationships between body weight and breeding parameters for Procellariiformes in general.