Hello all.
This morning I was at Sheepstation Creek Conservation Park near Caboolture in Queensland. Both White-bellied and Black-faced Cuckoo-shrikes are common here, and they are normally fairly easy to distinguish. One bird, however, had me puzzled. At first I thought it was a regulation BFCS, but on closer inspection it was more the size of a WBCS, has light half eye-ring (a feature of WBCS), and, even though it has a darker area the shape of that of a BFCS, if you look closely you can see a slightly darker facial mask area. The bill looks too small for BFCS. Now, I realise there are dark morphs of WBCS (which I’ve never seen), but I have only ever seen photos of birds with a totally dark head. So, I have three questions:
1. Do dark morph WBCS have gradations, or are they either all or nothing?
2. Do BFCS hybridise with WBCS?
3. Have I been duped by a juvenile?
A rather ordinary photo is here: http://www.pbase.com/image/150836159
Cheers Steve Murray
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Thanks to all who replied to my query about the White-bellied Cuckoo-shrike. It seems the dark morph birds do vary a bit and have been seen by everybody except me! I really need to get out more. Cheers Steve Murray
You are correct in saying it’s a White-bellied Cuckoo-shrike. This is not a hybrid, it is a straight out adult White-bellied Cuckoo-shrike. Below is what I found when I investigated this species, when writing the Field Identification text for HANZAB.
In SE White-bellied Cuckoo-shrikes vary considerably. There is the typical light morph, & there are the darkest birds, when can be very dark, black-hooded, darker grey above & barred below; these aren’t straight morphs, in between there is every kind of variation, they start from a few dark feathers in the ear-coverts, to patchy black head. One of the variations (as I’ve seen in skins) is a lot like an adult BFCS, plumage wise they tend to have a few odd black feathers outside the hood, on the upper breast or crown. I find there are characters that always separate WBCS from BFCS: (1) WBCS has a proportionately shorter, more compact stubbier bill (longer in BFCS). (2) WBCS is distinctly smaller, to be sure of this there has to be some comparison, for example if the bird in question is with other WBCSs then it should be about the same size; beware, it is very easy to get the size wrong in the field. (3) One other classic feature is very obvious in your photo, WBCS has much broa der white edges to it’s tertials & secondaries. (4) You are quite correct about the paler crescent behind the eye, this is never present on adult BFCS, however be careful it may not be present on all WBCS in this type of plumage. Hope this helps-Kevin Bartram
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Hi Greg & Steve,
I agree – a dark morph WBCS for mine…
Cheers, Martin Cachard Cairns
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Hi Steve,
I have seen dark morph White-bellied Cuckoo-shrikes with many variations on the black throat/head markings. I have seen ones like the one in your photo that has similar black areas to to Black-faced Cuckoo-shrike. Birds like this usually have some black blotching below the black bib, unlike the BFCS. This area is not visible in your photo. I don’t know whether they hybridise or not but I suspect that it is just natural variation in the WBCS. If the bird was smaller than a BFCS then it is not a young BFCS. Did it call? The heavy black marking on the lores of the bird in your photo only reaches the eye like a ‘normal’ morph WBCS.
I would say a dark morph WBCS.
Regards Greg Dr Greg. P. Clancy Ecologist and Birding-wildlife Guide | PO Box 63 Coutts Crossing NSW 2460 | 02 6649 3153 | 0429 601 960 http://www.gregclancyecologistguide.com