A couple of days ago I was at Olympic Park, and saw several darters amongst the cormorants on Lake Belvedere. I’ve seen darters in North Sydney, too, but the local ones are usually less easy to photograph.
Australasian Darters (Anhinga novaehollandae) look like a cross between a heron and a cormorant, but resemble the closely related cormorants in their habits. The males are black and handsomely marked, like this one pretending not to notice the bin chicken (ibis):
The female’s neck and head are paler, and creamy-white underneath, like this one drying her wings:
And the immature ones are even paler. The Size 20 feet are common to all darters:
This immature bird reminded me of the even younger pair I saw at Olympic Park about 10 months ago. Although they already had the black flight pinions and Size 20 pink feet of their parents, their bodies were covered in fluffy down, so I christened them the Kapok Kids.
(Kapok, the cotton-wool like substance produced by the kapok tree, was once used to fill life-jackets and padded jackets, like the one worn on Arctic convoys by the Kapok Kid in Alistair MacLean’s novel “HMS Ulysses”.)
The Kapok Kids were much more aggressive than your average fledgling. For them, feeding time began with both chicks rearing up menacingly when the parent (in this case the mother) arrived. As soon as she opened her beak, both would simultaneously dive down her gullet and ransack her stomach of its contents. Not a pretty sight!
Cormorants and darters have less oil in their feathers than ducks and other water birds. The feathers therefore become more waterlogged, causing the bird to float lower in the water. Darters in particular float with only their head and neck above water. The lower buoyancy makes it easier for them to dive and swim underwater, and to stalk and catch fish. When they emerge from the water, darters and cormorants have to dry out their waterlogged feathers – hence the spread wings when perching. They then preen their feathers carefully, using the oil gland at the base of their tail.
There are three other closely related species of darter – the Indian, American and African darters. All share the long kinked necks and sharp slender bills which they use to catch fish and other small aquatic animals.
Darters are readily distinguished from cormorants by their slender neck and head – the cormorant on the right has a much more distinct head.