Saturday, 7 January 2012

Having a whip(bird)around

Eastern whipbirds (Psophodes olivaceus) are difficult to photograph, not only because they scoot erratically through the undergrowth, but also because they invariably pick up a large leaf just as the shutter clicks. I have have taken many photos of what I thought were whipbirds, only to find that they are, in fact, of blurry leaves with feet sticking out from underneath them.

John Gould (1865: 314) described the eastern whipbird as shy and reclusive. As you can see from the photos below, he was spot on.
"...although its full notes — ending sharply like the crack of a whip — indicates its presence, it rarely exposes itself to view, but generally keeps in the midst of the densest foliage and among the thickest climbing plants, frequenting those that have intertwined themselves with the branches of the tallest shrubs, and those that form impenetrable masses near the ground, and through which it threads itself with utmost care. It is extremely animated and upright in all its actions."
I imagine that 'animated and upright' is a another way of saying 'frenetic'.

Peeka-


-boo!

The male bird's call is one of the most distinctive sounds of the rainforest. Composed of two elements — the first a drawn out whistle, the second a loud whipcrack — it comes in nine different versions. In seven of those the whipcrack is upwardly inflected; in the other two it trends down.

It forms the opening part of a duet between male and female birds. The female follows immediately with a two note response, her call so soon after the whipcrack that it sounds as though it has been uttered by the same bird.

Duet of male and female eastern whipbirds. (From Rogers, 2005)


The female's song also varies and her response depends on the male's lead in. In addition, females produce a call that is similar in structure to the male's whipcrack, but differs slightly in pitch and length.

Range of calls given by female eastern whipbirds.
A - C are responses to male calls, Song II is a solo call.
(From Rogers, 2005)

When a potential rival enters a male whipbird's territory, the territory-holder matches his song type. Female whipbirds do the same when other females intrude, often matching the song not only in type but also in timing.The calls overlap exactly. It is thought that territory-holding females use their calls to reinforce pair bonds when a lone, potentially rival, females encroaches, whereas males are a little more relaxed about it.

Whipbirds are monogamous, forming stable pair bonds in territories that are held from year to year and are not yielded readily. Male whipbirds contribute substantially to raising nestlings. They also occur in lower numbers than the females. Consequently, the more commonly observed male – male rivalry over females is reversed and females compete for males — although the competition is remarkably laid-back considering how excitable whipbirds are in most other aspects of their lifestyle.



References
Gould, J. (1865) Handbook of the Birds of Australia. Vol. 1. London: John Gould. 363 pp.

Rogers, A.C. (2005). Male and female song structure and singing behaviour in the duetting eastern whipbird, Psophodes olivaceus. Australian Journal of Zoology 53(3): 157 – 166.

Rogers, A.C., Mulder, R.A. & Langmore, N.E. (2006). Duet duels: sex differences in song matching in duetting eastern whipbirds. Animal Behaviour 72: 53 – 61.

Rogers, A.C., Langmore, N.E. & Mulder, R.A. (2007). Function of pair duets in the eastern whipbird: cooperative defense or sexual conflict? Behavioral Ecology 18(1): 182 – 188.

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