Sunday, August 27, 2023

Interesting Whimbrel with some pro-alboaxillaris features, Ma'agan Michael, 26/August/2023

Yesterday (August 26th, 2023) I went to Ma'agan Michael to twitch the Booted Warbler that had been found there by Igal Siman Tov. It's only the 5th record for Israel, and the first twitchable, great find! It took some searching until I eventually saw it; it didn't preform as well as it did on previous days so no photos. Still, I saw it well enough to count for an IL bimbo, with supercilium and all. 

However, this wasn't the most outstanding observation of that morning. While walking around with Amir Balaban in search of the skulking warbler, a quartet of Whimbrels flew by. Whimbrel is quite scarce in Israel, so without hesitation both of us rattled away with our cameras as they passed close, almost overhead. They flew by very fast, and both of us didn't get a chance to check them with our bins. Back home in the evening I downloaded the images to my computer, and noticed that one bird was unusual, the rear bird of the quartet. With the story of the once-though-extinct-now-super-rare Steppe Whimbrel in my mind, I always check Whimbrel underwings here, and this one certainly caught my eye (alas not in the field). It has essentially white underwing coverts, and limited spotting on the axillaries. It's pectoral band is nicely developed, contrasting with the white belly. 

Because the group passed almost directly overhead, we got no photos of the upperparts. This is all I got:

I plonked these images on Twitter in the evening; by then Bangladesh-based Gary Allport had already gone to sleep:
When Gary woke up in the morning he responded in length - thank you Gary! Gary agrees this is an interesting individual, with some pro-alboxillaris features, including the features mentioned above:

The pattern on the outer web of 5th outermost primary with four evenly-spaced white spots is good for alboxillaris:

Few dark spots can be seen on the uppertail coverts but this side views isn't sufficient. Eventually the interim conclusion about this bird is that according to current knowledge of alboxillaris it's probably not good enough. There is too much spotting on the axillaries; the underwing coverts are not strikingly white enough; and the size and structure don't differ from the other nominate phaeopus, including bill length. With missing features like the rump and tail pattern, this bird will remain currently as an 'interesting bird'. However, this bird is a fresh juvenile. This plumage is poorly known in alboxillaris - only one documented individual to my knowledge. Hopefully this bird hasn't moved on yet and it will be relocated in the next few days.

So, it's worth keeping track of this Ma'agan Michael bird. Maybe in the future, with better knowledge of the amount of variation shown in juvenile alboxillaris, new insight could provide more confidence in retrospective identification of this individual.

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