Egg laying in the Mediterranean shearwater P. yelkouan in Malta

Abstract

In the Maltese Islands the Mediterranean Shearwater Puflinus yelkouan has been recorded laying generally in late March or early April. While on a night visit to a partly accessible colony of this species in the northern part of Malta on 7 March 1991 an adult bird was found incubating its single egg, very deep inside a burrow in the cliffs. On the same night seven other birds were caught for ringing before entering their burrow. During the ringing process three adult females were found ready for laying. The egg inside could easily be felt and the cloaca was already much extended.