I hope Martin forgives me for turning this into my personal blog. But this bird stirred a fascinating discussion among some top birders, and deserves one last post.
So after lots of thinking and reading and discussing, the concensus on this bird now is that it’s a good candidate for atrifrons. This happened after seeing more images of the bird, better illustrating its petite size, and understanding that wing pattern and bill structure are highly variable in both species, and identification shouldn’t be based on these features only. This bird showed a wing pattern normally associated with greater (bulging white wingbar on inner primaries), as mentioned in literature. Well, not anymore.
Also, this bird showed a bill structure similar to the bird from Kenya in my previous post – long and rather thin, with slightly bulbous lower mandible. Again, according to literature this is not very good for lesser, but better for greater.
So what do we have on this bird?
1. Timing of moult – lesser moults later than greater, which is a good pointer for lesser – at least in Israel a bird in summer plumage in late July or August should be lesser. I know little about how eastern leschenaulti moult.
2. General size and structure – small. Not the most ‘delicate’ atrifrons in the world though.
3. Leg colour – basically dark (though often hard to tell in the field).
4. Head pattern – massive black mask.
5. Dull grey mantle. Greater normally has brighter rufouns mantle, but surely this is affected by wear?
At least my understanding from recent days is that some features widely mentioned as distinguishing between greater and lesser are invalid or at least very variable, such as wing pattern and bill structure. More work is needed on separation of columbinus and western atrifrons, that appear to be very close to each other.
And a couple of lessons for me – 1) always be extra cautious about identifying birds from images without seeing them and 2) never be definitive about such difficult taxa; always use indefinite terms such as ‘looks like’, ‘good candidate’ etc.
I want to thank all the people who contributed to this discussion, in Israel and overseas.