Great Crested Grebe Eating Nestling Passerine
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Australian Field Ornithology 2012, 29, 105–106 Great Crested Grebe eating nestling passerine Stephanie J. Tyler Yew Tree Cottage, Lone Lane, Penallt, Monmouthshire NP25 4AJ, Wales, United Kingdom Email: [email protected] Summary. A Great Crested Grebe Podiceps cristatus was observed offering a dead nestling passerine to its young before eating the dead nestling itself. Birds do not appear to be common items of prey for Great Crested Grebes Podiceps cristatus. The Grebe’s diet comprises mainly fish of a wide variety of species, as well as a diversity of insects and aquatic invertebrates, such as crustaceans and molluscs, with some adult and larval amphibians also taken (Limona & del Hoyo 1992; Fjeldså 2004). In southern Africa, Great Crested Grebes prey almost exclusively on small fish, aquatic insects, crustaceans and tadpoles (Hockey et al. 2005). Feathers and vegetable matter have been recovered from stomachs of Great Crested Grebes, but it has been suggested that feathers had been ingested to wrap fish bones for regurgitation as pellets, as in other grebes (Brown et al. 1982; Fjeldså 2004). Likewise, Marchant & Higgins (1990) mentioned plucked feathers being ingested. Small mammals have been recorded in the diet of a Little Grebe Tachybaptus ruficollis (Fisher 2005) and an Australasian Grebe T. novaehollandiae (McAllan et al. 2008), but in the latter case the small rodent was thought to have been taken as carrion. I was birdwatching on 10 September 2011 at Lake Bindegolly (28°06′S, 144°12′E), a Ramsar site and National Park in Queensland. Among the many waterbirds present were a few Great Crested Grebes. At ~1000 h, I was watching an adult Grebe with a half-grown juvenile when another adult appeared, swimming towards its apparent mate and chick. It was carrying in its bill what I had at first assumed was a lump of vegetation. As the bird drew nearer, I could see through binoculars that it was carrying a nestling passerine, ~8–10 days old judging by the primary feathers just appearing through the pins. The Grebe swam to the chick and tried to feed the dead nestling to it, but the chick dropped the nestling in the water. This was repeated, with the adult picking up the dead bird and macerating it with its bill before trying again to feed it to the chick; after three or four failed attempts by the chick to swallow it, the adult picked up the dead nestling and swallowed it. Many Fairy Martins Petrochelidon ariel were nesting under the bridge, and at first I thought that the Great Crested Grebe may have picked up a young Martin fallen from its nest. However, the legs of the nestling were clearly too long for a hirundine nestling, and the corpse was too large for a Fairy Martin nestling. Whether the adult Grebe had raided a nest of another species overhanging the water or had opportunistically picked up a fallen chick from the water is unknown, but birds clearly, if only occasionally, do contribute to the diet of the species. 106 Great Crested Grebe eats nestling passerine S.J. Tyler Thanks go to Ian McAllan and Shirley Cook for their helpful comments on a draft of this note. References Brown, L.H., Urban, E.K. & Newman, K. (1982). The Birds of Africa, Volume 1. Academic Press, London. Fisher, R. (2005). Little Grebe swallowing small mammal. British Birds 98, 156. Fjeldså, J. (2004). The Grebes. Oxford University Press, Oxford, UK. Hockey, P. Dean, R. & Ryan, P. (2005). Roberts Birds of Southern Africa, 7th edn. The Trustees of the John Voelcker Bird Book Fund, Cape Town. Limona, F. & del Hoyo, J. (1992). Family Podicipedidae (grebes). In: del Hoyo, J., Elliott, A. & Sargatal, J. (Eds). Handbook of the Birds of the World, Volume 1: Ostrich to Ducks, pp. 174–196. Lynx Edicions, Barcelona. Marchant, S. & Higgins, P.J. (1990). Handbook of Australian, New Zealand & Antarctic Birds, Volume 1: Ratites to Ducks. Oxford University Press, Melbourne. McAllan, I.A.W., Knight, B. & O’Brien, R.M. (2008). Australasian Grebe eats a mammal. Australian Field Ornithology 25, 44–45. Received 13 February 2010.