Many a visitor would admit that Australian garden birds are weird and exotic, but they might not realise that this applies to their life histories, too. You only have to go for a short walk encounter the Noisy Miner, for example. This bird lives in possibly the most complex group system of any bird in the world: individuals are members of pairs, then families, then clans, and males also have “clubs” or “coteries” to which they belong. The “clan” system gives many males access to a single breeding female, and the advantage to that female is that young birds in the nest and outside are extraordinarily well cared for: a single nestling can be fed by as many as 10 different males. This morning I happened to come across a well fledged young in a berry-bearing tree. It just sat there, with food all around, just waiting while at least three adults attended to it.
Meanwhile many visitors delight in seeing another common species, the Superb Fairywren. This bird also lives in groups, consisting of a male, a female and a number of
youngsters. All members of the group contribute to nest building, feeding the young and in territorial defence. The youngsters, especially, the males, may remain in this family unti for as long as six years before breeding themselves. What is truly extraordinary is that, despite the homely system, some 70% of all young are sired outside the pair bond. Strange males routinely trespass and mate with the incumbent female, even when the male is present – and the latter doesn’t seem to be fussed..
Talking of being fussed, this Sulphur-crested Cockatoo was certainly fussed the other day when a couple of Noisy Miners got too close to its nest hole. You can imagine the racket!