Thursday, 3 March 2016

Mystery Bird

Ken Bissett's photograph of the mystery bird posted on the chatline

There was a recent request for help with the identification of the above mystery bird in the local Canberra Ornithologists' Group chatline ( The query was by Ken Bissett of a small bird he had seen at Mulligan's Flat Nature Reserve, an area of woodland north of Canberra. The first online suggestion was that it might be a juvenile Brown-headed Honeyeater Melithreptus brevirostris, and another was a juvenile Western Gerygone Gerygone fusca. It is now early autumn and there are many young birds about, with confusing plumages. The latter is correct and I present below a selection of images to help explain the reasoning for this conclusion.

A first-year Brown-headed Honeyeater
Both species are woodland birds with light greenish/grey upper-parts and pale under-parts, and they are similar in size, about 100 mm in total length. However these are relative colour comparisons which can vary between individuals at different times of the year, so it is better to refer to specific features.

The same Brown-headed Honeyeater in profile
Ken's bird has a pale grey crown and dark grey legs and feet whereas a young, first year Brown-headed Honeyeater has a pale brown crown as pointed out by Mark Clayton, and pale yellow legs and feet, as pointed out by Richard Allen, in replies to the query. This Brown-headed honeyeater also shows a faint buff/yellow line across the nape.

An adult Brown-headed Honeyeater
For comparison between young and adult Brown-headed Honeyeaters, note the dark bill in the adult and the dark greyish-brown crown and side of head, with a clear white line across the nape.

A first-year Western Gerygone
A young, first-year Western Gerygone has a grey crown with no line across the nape (there is no such line on Ken's bird). It has a white eyestripe, emphasised by a dark line between the eye and the base of the bill. This is faint on Ken's bird, but it is there.

The same first-year Western Gerygone seen from the rear
When seen from the rear, the gerygone has obvious white markings on the tips of its tail feathers, which the honeyeater does not have. An alternative, old, name for the gerygone is the White-tailed Warbler, so that is a good feature to look for.

An adult Western Gerygone
There is no ambiguity between the adults of the gerygone and honeyeater. The adult Brown-headed Honeyeater has bold dark head markings and yellow legs and feet. The adult Western Gerygone has no bold head markings, only the small eyestripe. Its main distinguishing features are its red eye, grey legs and feet, and a dark band across its 'white-tail'.

The same adult Western Gerygone seen from the rear

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