Fish-spawn entangled to the legs of Cory's shearwaters Calonectris diomedea

Abstract

A colony of Cory's Shearwater Calonectris diomedea in the south of Malta, where six nest sites are accessible, was visited during the day on 22 May 1987 to determine if there were any incubating birds. None were found. However, the birds started arriving at the colony at night and three birds were caught. All were females bearing rings and were known to have occupied nests in that area, suggesting that the pre-laying exodus was terminating and that females had started to visit their nest-sites to lay. In fact, on visiting the area three days later, all nests were occupied by incubating birds. The unusual thing was that two of the birds examined that night had small lumps of fish-spawn entangled to their rings.