The conditions of the sighting were excellent; the bird was seen in the clear, on a bright, sunny morning, at eye-level. The bird perched at the top of a small tree and sang, for about 2 minutes, at a range of less than ten metres. (The fact that I didn’t get a photo is, frankly, stupid. I would have been so easy… but I’m a “get notes first” sort of person.) The following are our 'raw' field notes from the day:
-bill ivory(By the way, in case the last point is at all unclear, it just means that the change in colour between head and back is sudden, no blending).
-grey head and throat
-yellow vent, belly
-cherupcheer whistle, repeats
-head breaks sharply at back
We didn’t consult a field guide at the time, since the view was so good, I thought that there would be no ambiguity. When I did get around to consulting my “Birds of Chile” (Jaramillo), I found that it was entirely clear that it was a Sierra-finch – but which one?
Not all the plumage features (which were very well-observed) line up with any one species; in particular, I remember saying at the time (although it didn’t make it into our notes) that the head/back contrast reminded me very much of a similar feature on the Northern Parula – reinforcing the notion of a green back.
Anybody got enough experience with this genus to sort out what trumps what, amongst Sierra-finches?