The Establishment of a New Brown Noddy Anous stolidus Breeding Colony off South-Western Australia

Abstract

A new breeding colony of the Brown Noddy, which started on Lancelin Island in south-western Australia around 1991, expanded exponentially between 1994–95 and 1996–97. This growth in the number of breeding pairs resulted from the immigration of noddies from another breeding area, probably the Houtman Abrolhos 275 km to the north. In the 1996–97 breeding season there were two distinct waves of laying. The initial laying period, which had occurred in the previous two seasons, peaked in early November and was more synchronous than the second one. The second wave peaked in early December and resulted from laying by new arrivals with probably some re-laying from earlier losses. There was a significant reduction in clutch volume after the first 15 days of laying. Factors which may have produced a decline in egg size later in the season are discussed.