Diet of little penguins, Eudyptula minor, from Penguin Island, Western Australia

Abstract

Between March 1986 and March 1987, the stomach contents of 236 little penguins on Penguin Island, Western Australia, were obtained using an emetic. The 1392 prey items identified included 16 fish species, one squid and one prawn, but four fishes comprised most of the birds' diet. Hyperlophus vittatus was taken throughout the year, Sardinops neopilchardus and Hyporhamphus melanochir mainly in winter and Spratelloides robustus during spring/summer. The penguins are largely opportunistic in their foraging and their diet appears to be similar to the fish species caught locally by commercial bait fishermen.

Surface Nesting by Little Penguins on Penguin Island, Western Australia

“…Thus, high temperatures, exacerbated by being forced to nest on the surface, rather than in burrows, may account, in part, for the unusual winter breeding chronology of Little Penguins on Penguin Island. There appears to be little seasonal or annual variation in the diet of Little Penguins from Penguin Island, which consists mainly of small, schooling fish caught inshore (Klomp & Wooller 1988a;Wienecke 1989), and changes in food availabili- ty seem unlikely to influence the timing of breeding in most years. Indeed, this relatively favourable trophic environment may be linked to the very prolonged breeding period at this colony (Dunlop & Wooller 1986) and the significantly larger size of the birds there (Klomp & Wooller 1988b).…”

“…There appears to be little seasonal or annual variation in the diet of Little Penguins from Penguin Island, which consists mainly of small, schooling fish caught inshore (Klomp & Wooller 1988a;Wienecke 1989), and changes in food availabili- ty seem unlikely to influence the timing of breeding in most years. Indeed, this relatively favourable trophic environment may be linked to the very prolonged breeding period at this colony (Dunlop & Wooller 1986) and the significantly larger size of the birds there (Klomp & Wooller 1988b). Lack of suitable substrate does not permit Little Penguins to burrow on Penguin Island and large caves are few; neighbouring islands are very similar.…”

Few genetic differences between Victorian and Western Australian blue penguins,Eudyptula minor

“…Additionally, there was limited or shallow phylogeographic structure within the Australian clade, indicating that the populations on the two coasts of Australia plus the otago population in New Zealand have occupied ranges free of impediments to gene flow (Avise 1994). Klomp & Wooller (1988) suggested that Western Australian blue penguins may be larger because of a more favourable climate and food supply, as an alternative to genetic isolation. We agree that favourable food and/or climate are more likely than genetic isolation to have produced the morphological differences between populations breeding on the two coasts.…”

“…Several subspecies have been distinguished on morphometric data such as bill size, body weight and tarsus length (Kinsky & Falla 1976). Blue penguins from Western Australia are heavier and have longer bills than blue penguins elsewhere in Australia (mean 1390 g compared with 1207 g in Victoria during the nonmoulting season, and the size difference between Penguin Island, Western Australia penguins and some of the other blue penguins is greater than the differences between several of the subspecies (Klomp & Wooller 1988). Comparison of random amplified polymorphic DNA from samples collected from birds breeding on Jarvis Bay, New South Wales and Penguin Island, Western Australia found a slight separation between the two populations (Wienecke 1993).…”

“…Comparison of random amplified polymorphic DNA from samples collected from birds breeding on Jarvis Bay, New South Wales and Penguin Island, Western Australia found a slight separation between the two populations (Wienecke 1993). Klomp & Wooller (1988) therefore proposed that the larger size of birds from Penguin Island may be due either to the relative isolation of these birds at the northern limit of their distribution, or to a more favourable climate and food supply. in this study, we obtained genetic sequences for two mitochondrial regions, the cytochrome-b gene which evolves moderately quickly (Nunn et al 1996) and the faster-evolving control region (Freeland & Boag 1999;Lambert et al 2002) to investigate if there are genetic differences between blue penguins breeding on the east and west coasts of Australia.…”