Last week I gave you this LBJ (Little Brown Job) to have a go at identifying:
This is one of those birds that can be hard to identify in the field when it’s alive, but it can be even harder after spending over 100 years on display in a Museum.
I’ve mentioned this before – when dealing with taxidermy, damage to the pigments in fur and feathers caused by light exposure can significantly alter the colour of a specimen. This it will often happen preferentially – so you might find that black and red is affected more noticeably than brown for example, creating misleading colour combinations. This fading also happens on bills and claws, sometimes changing them to a light brown or yellow.
Another common issue with specimens is that on death the colour of skin can rapidly fade. This means that some common colour features that may be used in identification (e.g. yellow legs) may cease to be reliable. Some taxidermists paint these colour features back in, but some don’t.
All of this adds to the challenge, but when you have an inkling that you’re dealing with a faded specimen you can make some mental adjustments about how to interpret the appearance. This usually means putting greater emphasis on size, shape and pattern of features rather than on colour.
In the case of this specimen, most people narrowed it down to a member of the genus Linaria, but the issue with fading meant that the species that almost everyone opted for was the Twite, whereas the specimen is actually a male Common Linnet Linaria cannabina (Linnaeus, 1758), which I assume is in its winter plumage, unless the fading is REALLY bad (in the summer the males have quite a lot of red on the head and breast). The specimen was collected in Dublin and given to the Dead Zoo in 1915.
A useful feature for distinguishing between the species without relying on colour is the bill, which in the Twite is relatively small. Twites also have heavy streaking of the plumage, which should be somewhat apparent even in a faded specimen. Neither of these are apparent in this specimen.
There is a useful video guide made by the British Trust for Ornithology for distinguishing between Linnets and Twites in the field. It doesn’t extend to museum specimens, but it’s an excellent place to start!
Good one! Indeed fading is something to take into account when you try to ID an old mount. Same with specimens from captivity. You often see linnets, redpolls and crossbills from captivity with yellow feathers where there should be red feathers. This is caused by inadequate feeding.