Another mystery AK bird

[Gavin Bieber]

Mark Schwan photographed this mystery bird along the SE Alaska coastline near Juneau earlier this year (I don't have a date). The masked look and pale rump were apparently evident in the field. Mark spent little time studying the bird, concentrating instead on taking photographs. Unfortunately the bird was not seen again. Opinions have been solicited on the admittedly poor photos and several interesting options have been mentioned. Any comments as to the ID (even to group) of this bird would be appreciated, especially from anyone with experience in eastern Asia.

[Gavin Bieber]

Just heard from the photographer that the pictures were taken on July 14, 2009.

[darrenjhughes]

It looks a little like a Crag Martin but this speices should have white spots in the tail maybe Rock Martin.The general shape of the bird would suggest something of this ilk.

[AndyB]

Good one! I'm sure I'm making this way harder than it should be. First 2 photos, looked a little like a storm-petrel but the next three clearly rule that out and would agree with Darren that it appears to a hirundine. However, I'm puzzled by what appears to a large pale (horn-colored) bill in some photos leading me to double-check the woodswallows. Nothing really fits well. Perhaps, bill color is a photographic effect? Hopefully, somebody sensible can come along and put me out of my misery and state the obvious.

[LeeEvans]

This bird does have similarities to the Martins (Ptyonoprogne) or even larks but I can't help feeling that it is a seabird, perhaps a petrel species. A remarkably difficult challenge indeed

[Colin Key]

It looks a little like a Crag Martin but this speices should have white spots in the tail maybe Rock Martin.The general shape of the bird would suggest something of this ilk.

Image #4 has some semblance to a "martin sp.", but surely the other shots show a much bulkier bird. I can see the "petrel attitude", but on the basis of these shots :err::err::err:

Colin

[KenM]

Definitely has a 'hirundine look' about it, how about immature Purple Martin with a less than perfectly formed tail?

[W. Ruskin Butterfield]

You gentlemen are all very brave. It might be nice to have field notes especially about the size of the bird. I noticed the exif data shows this is a D-90 my dream camera, I am jealous. My first thought on seeing the first photo was a falconet. Black-thighed Falconet might fit the bill. Sort of peregrine face pattern, but brown on head and dark wings and a yellow bill. Its tail might be too long for this bird but maybe it is damaged?
http://www.pbase.com/cajuca/image/81458122 .

[Mark Schwan]

I have never posted on Surfbirds, but felt I needed to provide some information since I took the pictures. This bird was aerial feeding for insects over a series of pools in a fast, clear water stream. The bird was in association with Barn and Violet-green Swallows. This bird appeared to be the same size as the other swallows and exhibited rapid wing beats, similar to the Violet-greens. Yes, I was using a Nikon D90 with the 70-300mm VR lens, shooting at high ISO (3200), hence fast shutter speeds, and using spot metering and focusing, along with continuous auto focus mode. Unfortunately, I mostly was not spot on, hence the blurry bird pictures.

Thank you.

[darrenjhughes]

I can see the Petrel thing but still think its a martin type purple martin not a bad shout is a juv likley in July I dont know personly.Wood Swallow I have only seen White Breasted right shape wrong colour.The size is hard to judge:err:

[darrenjhughes]

On photo 5 the secondries seem to be in pretty bad shape would this not rule out a juv at this time of year.They should be all fresh.What about Plain Martin (R.p. chinensis)

[David Russell]

With the generally bulky jizz, pale bill and dark loral area my immediate impression was of a Woodswallow, but the only species which seems remotely possible would be White-breasted (ssp leucorynchus) which while largely resident north to Southern China has apparently reached Korea and Japan. Interestingly this photo from the OBC archive shows a juvenile from Malaysia in May,showing a lot less contrast than in adults:

http://orientalbirdimages.org/search.php?action=searchresult&Bird_ID=2198

[Frigatenerd]

I'll go with a woodswallow (Artamidae), perhaps dusky woodswallow. Dark mask and horn-colored bill look distinctive.

[AndyB]

Hi Mark, well done on getting these shots and what is surely an interesting sighting. Is there any chance you have a larger version of that first image? I feel there could be some good detail on the head and bill which we can't see on this down-sized jpeg.

[LeeEvans]

Now that we have had some clarification from the observer what the bird was doing and how large it was you can forget my petrel or seabird suggestion - it is far more likely to be a sub-adult PURPLE MARTIN as others have mentioned.

It is a brave person indeed to make 'guesses' on just a series of photographs like this, with no real way of determining the species. You really must be given the field characteristics and detail relevant to the sighting. Thi sjust proves how difficult assessing record photographs is.

[Peter Martin Phillips]

In the last pic the bird has almost a 'young starling jiz' about it. I think its a Purple Martin. This must be the default species surely? Unless some body can rule out Purple Martin, I think this is the safest bet. I think the horn coloured bill might be a trick of the light. How rare is Purple Martin in SE Alkaska?
Looking forward to one winging its way over here this autumn!

[Mark Schwan]

Well, Purple Martin is casual in Alaska and there are a few records from Southeast Alaska. I have seen a couple in Juneau. However, I never even considered it with regard to this bird because they are substantially larger than the other swallows we have here. And, as I posted earlier, this bird was in association with Barn and Violet-greens and was basically the same size as the Violet-greens. Obviously the pictures are no help on size, but I believe my assessment on size relative to the other birds is accurate, and therefore would make Purple Martin an unlikely prospect. Thanks.

[MichaelF]

Well, Purple Martin is casual in Alaska .... However, I never even considered it with regard to this bird because they are substantially larger than the other swallows we have here. And, as I posted earlier, this bird was in association with Barn and Violet-greens and was basically the same size as the Violet-greens. Obviously the pictures are no help on size, but I believe my assessment on size relative to the other birds is accurate, and therefore would make Purple Martin an unlikely prospect. Thanks.
That would then count out the Woodswallow suggestion too, looked up and they're about the same size as Purple Martin

Has Northern Rough-winged Swallow been excluded as an option? I'm not familiar with them; looking at pics, that should show a darker underwing, but that could be influenced by lighting?

[AndyB]

Yes, size would seem to eliminate Purple Martin and Purple Martin certainly would be a rare sighting too. It would need to be a runt, aberrantly colored Purple Martin. Whatever it is, it's odd and possibly aberrant as it doesn't seem to fit any species...

So if we are going down the path of aberrant, we might look at the commoner, more expected species. Michael, I have wondered if it could be an aberrant Northern Rough-winged or perhaps Violet-green is more likely (due to the paler sides of the rump visible in a number of photos).

Mark has kindly provided a larger image of a couple of the shots that I attach below. It does seem to have a pale bill (but not orange as in one of the previous shots above) and uniformly chocolate brown head and throat with dusky brown underparts. The apparent warm brown underwing coverts also are at odds with the expected north american hirundines. I guess we just have to leave this one unidentified...:err:

[jamesg]

Given the size, shape, ghosting of pale rump-sides (and Mark's description), I'd say melanistic Violet Green Swallow has got to be the most likely explanation. This kind of melanism has been recorded previously in hirundines, e.g. this Tree Swallow:
http://www.wildlifebc.org/UserFiles/File/3_2_Campbell_Siddle.pdf

This paper also provides a reference for a previous melanistic Violet Green Swallow record:
http://www.jstor.org/pss/4511208

A very unusual bird nevertheless...

[David Russell1]

Sorry to bang on insanely about this, but there are a number of features on this bird that that seem to me are at odds with the martin/ swallow route:

Bill structure - looks far too heavily based
Bill colour - consistently pale apparently greyish in colour
Pale rump feathering
Dark loral feathering
General structure - probably too heavy for Nearctic hirundines bar Purple and I cannot reconcile the bill and rump features with that species
Overall dusky colouration on the upperparts

Then we have this news from Korea:

http://www.surfbirds.com/birdingmail/Mail/OrientalBirding/536649

This could explain the relative lack of contrast on the underparts?

I would just hate to see a really good record get away!!

[jamesg]

Hi David,

I suspect most of the apparent structural anomalies are 'optical illusions' associated with the melanism...

Some web examples to compare:
http://farm3.static.flickr.com/2422/3666221952_a3f096db81.jpg?v=0
http://www.toynutz.com/0001Swallow_Violet-green3.jpg
http://www.surfbirds.com/forum/attachment.php?attachmentid=1914&d=1248829739

Exciting as a vagrant woodswallow would be, they really are completely different beasts - hulking great things with totally different flight action to hirundines.

[W. Ruskin Butterfield]

Sutton, Records from the Arizona Region. Auk v. 60 p 345-350 (1943)
Northern Violet-green Swallow, …A breeding male taken May 30 on the east side of Mt. Wrightson (at 8600 feet) is curiously colored, the entire upper parts being so dark and so little glosses with green and violet as to be almost blackish. The sides of the face and under parts are white, as in normal specimens. All the plumage of the back and upper rump is faintly barred. The writer has not encountered a comparable case of melanism anywhere among the Hirunduinidae.


http://elibrary.unm.edu/sora/Auk/v060n03/p0345-p0350.pdf .

[AndyB]

Thanks for the melanistic swallow links - interesting. Mark had remarked to me that his first thought when he was watching the birds was that it could be an aberrant/melanistic Violet-green, so does appear that would be the most logical explanation for this bird.

I'll add a link too. Although not relevant so much to the AK bird, the following article documents a potential Violet-green x Cliff that produces a bird that looks quite Cave-like:
http://www.bcfo.ca/publications/bcbirds-articles/vol_10/Whittington-2000.pdf