Notes on Common Diving-Petrels Pelecanoides urinatrix Found Beach-washed in Victoria, 1985

Abstract

Morphometric, reproductive and plumage details are presented for a sample of Common Diving-Petrels found dead along Victorian beaches in early August 1985. Males predominated in the sexed sample (100 birds) and they were generally larger and heavier than females. Gonads of most males were large but whilst ovarian follicles were usually small, five females had either an egg or enlarged follicles. Food was not present in oesophagi or gizzards and birds were emaciated, with no obvious body fat and apparently atrophied muscles. The petrels represented birds (perhaps of local origin) wrecked at or just following egg-laying, presumably due to severe storms. Bill depths and widths, and wing lengths of the beach-washed birds were larger than those of museum specimens, suggesting that shrinkage affects some mensural characters. Comparison of morphometric data and plumage details of birds from this wreck with previously published data suggests that there is a need to reconsider the status of some subspecies of urinatrix. In particular we suggest that, apart from perhaps dacunhae, present data are insufficient to sustain other than urinatrix. In future examinations sample size, sex and age of fresh specimens should be taken into consideration. It follows too that earlier records of P. u. exsul in Australia are questionable.