with Red in the Tail
photos by Harry Scott
A Black-throated Thrush was found in Hugh Addlesee’s mothers garden in Banchory, c40 miles inland, west of Aberdeen in late March 2013. Access was arranged and local birders were treated to very close views through the kitchen window. One of the features of the bird was the presence of deep orange/rufous at the base of the outer tail feathers along the outer webs. Some even suggested (perhaps tongue -in-cheek) it could at times look like a “Black-throated Thrush from in front and a Red-throated from behind”
Of course, even though some of us were delighted to see this bird with it’s Redstart-like tail another one would be much appreciated!
Whats does this presence of rufous colour in the tail mean (more obvious from some angles than others)? This Banchory bird looks essentially a seemingly straightforward Back-throated Thrush.
The ‘Thrushes Book’ would point to this bird being an ‘intermediate’ or hybrid. The colour plate 40 on Dark-throated Thrushes (Red and Black) illustrates an atrogularis (Black-throated) tail pattern and states “all dark and show no orange or red”. Furthermore the text on page 379 reads: “Intermediates or hybrids usually resemble ‘Black-throated Thrush’… both sexes have some rust-brown or reddish in the tail (usually on the inner webs) but this can vary in extent from very little (and possibly not visible in the field) in the outer feathers to as much as nominate ruficollis.”
However on the Banchory bird there is no purple-black or admixed reddish feathering in the breast usually associated with more obvious intermediates.
What does it all mean? 🙂
The Fuzzy Zone
For me it’s the fuzzy zone. It may be that it’s actually normal for some core range Black-throated to have a bit of red in the tail. Or maybe they never do as the ‘Thrushes book’ seems to indicate? I don’t know.
The same kind of questions can be attributed to the Margate Dusky Thrush. For me it too just about falls into the (uncomfortable) fuzzy zone (at the moment – hoping to explore this subject little more and open to change my mind). I think and have been reassured that some 2cy female Dusky Thrushes can come close to this in appearance, but I think some of its apparent plumage characters still place it in the fuzzy zone. And that’s how it is with some closely related taxa that hybridise/ interbreed regularly. Isn’t it? Not always simple or straightforward, frustrating and sometimes fuzzy.
And with lots to learn.
Nils covers the fuzzy zone here: “Some ind show (sometimes very slight) mixed features of either Black-throated or Red-throated, or features of Dusky Thrush/ Naumann’s Thrush. these ind are ether ‘infected’ by genes of another taxon or show normal variation within a single taxon.”
Thanks and big nods in prep of this post to: Richard ‘what does it all mean’ Schofield, Hugh Addlesee, Paul Baxter and of course Harry Scott for use of these stunning photos.