Surface Nesting by Little Penguins on Penguin Island, Western Australia

The Little Penguin Eudyptula minor reaches the northem limit of its breeding range in Western Australia on Penguin Island, 42 km south-west of Perth (Blakers et al. 1984), where up to 500 breed annually. Members of this isolated population breed from April to November, rather than in spring and summer as is more common elsewhere (Dunlop & Wooller 1986; Stahel & Gales 1987). Penguin Island is a 12.5 ha limestone island, thinly covered in places by Holocene aeolian sands bearing low bushes and shrubs (Chape 1984). Lack of a cohesive substrate results in few penguins digging burrows and most nest under dense bushes and shrubs (Dunlop et al. 1988). The island lies 600 m offshore, close to a metropolitan area, making these surface-nesting penguins potentially vulnerable to disturbance by visitors. This paper examines the use of Little Penguin nests in relation to vegetation and human activity and explores possible links between surface nesting and the winter breeding regime of the species.