Birding Alaska

First cycle Thayer’s Gull Larus thayeri, Homer Spit, 25 February 2010.

Thayer’s Gull is a good find in Homer in the winter.  This first cycle bird was in a flock of 4,000 gulls at the offal discharge site on the end of the Homer Spit.  It was first reported by Martin Renner on 21 February.  Rich MacIntosh and I found the bird again on 25 February and got these photos.  Most of the gulls were Glaucous-winged L. glaucescens, and Mew Gulls L. canus brachyrhynchus.  Also present in the flock was one first cycle Glaucous Gull L. hyperboreus and an adult Herring Gull L. argentatus smithsonianus.

Structurally this Thayer’s Gull is identified by it’s smaller size, more rounded head, smaller and narrower bill, and wings that are proportionately longer than the abundant Glaucous-winged Gull.  Also, on this Thayer’s Gull the outer primaries, tail and tertials are darker than the rest of the upper parts–this is evident on both the sitting an the flying bird.  Note that the primaries of this Thayer’s Gull are dark brownish with pale fringes.  A first cycle Herring Gull would have more blackish primary tips lacking the pale fringes.  The upperparts of a first cycle Glaucous-winged Gull is very uniform in tone and the primaries, tail and tertials do not contrast with the rest of the upperparts.  See the next two photos for comparison with Glaucous-winged Gull.

First cycle Glaucous-winged Gull Larus glaucescens, Cordova, 30 December 2005.

First cycle Glaucous-winged Gull, southern Bering Sea, 26 February 2009.

On both of these Glaucous-winged Gulls note the completely uniform tone of the upper parts.  There is no contrast between the tail, outer primaries, tertials and the rest of the upper parts.

Often when a species has an obvious and diagnostic field mark the tendency is to quickly identify the bird, ignore its other marks, and move on.  Identifying a Red-legged Kittiwake is easy if you see the field mark for which the bird is named, and if you travel to the Pribilof Islands during the breeding season you’ll have that opportunity.  However, on a flying bird or a bird seen at sea the red legs are difficult to see, so to pick out an out of range Red-legged Kittiwake you’ll need to focus on other identifying marks.  Once learned, these marks help to make the identification of a flying Red-legged Kittiwake straight forward even at a distance.

Red-legged Kittiwake and the similar and more widespread Black-legged Kittiwake are the only gulls in the genus Rissa. Both are small, cliff-nesting gulls that spend the non-breeding season primarily at sea.  Unlike the Black-legged Kittiwake which is circumpolar in distribution the Red-legged is endemic to the Bering Sea region, nesting at the Pribilof Islands and a few islands in the Aleutians, most notably Bogoslof and Buldir Island.  The species also breeds at the Commander Islands, in the waters of the Russian Bering Sea (Gibson and Byrd 2007).  Red-legged Kittiwake is rarely seen at sea away from its colonies and its winter distribution is poorly studied.  There are records of Red-legged Kittiwake for the Gulf of Alaska (Iseib and Kessel 1973) and even as far south as southern California (Cambell et al. 2008).

Red-legged Kittiwake Rissa brevirostris, St. Paul Island, Pribilofs, 5 July 2006.

Black-legged Kittiwake Rissa trydactyla, Eastern Bering Sea, 25 July 2009.

On the above pictures you can see that Red-legged Kittiwake is smaller, more compact, and slightly shorter legged than Black-legged.  On this bird note the short bill–for which it’s named brevirostris–and the large, round eye.  This imparts a gentle dove-like and “cute” expression that is lacking on the longer-billed Black-legged Kittiwake.

Red-legged Kittiwake (top) and Black-legged Kittiwake (bottom) in flight, Bering Sea, 4 October 2009.

These next two photos show the upperwing of both species in flight.  On the Red-legged Kittiwake the upperwing is uniformly slaty gray.  On the Black-legged Kittiwake the upperwing is light gray, especially on the outer wing, or “hand”, which is paler gray than the inner wing.  Even at a distance this two-toned appearance to the wing is evident.  Because of the paler wing on the Black-legged Kittiwake, the white trailing edge to the secondaries contrasts less with the upperwing coverts and there is no striking trailing edge to the primaries.  On the Red-legged Kittiwake upperwing note the strong contrast between the trailing edge and the upperwing coverts.  This contrast is evident on both the secondaries and the primaries.  Red-legged Kittiwake also appears more compact in flight with smoother wingbeats.  The small bill and large eye of the Red-legged Kittiwake are also evident in these flight shots.

Red-legged Kittiwake (top) and Black-legged Kittiwake (bottom) in flight, Bering Sea, 4 October 2009.

The underwing pattern of the two species differs as well.  On the Black-legged the underwing is gleaming white.  On the Red-legged the underwing is grayish on the innerwing and darker gray on the outerwing.  This makes for much less contrast between the primary tips and the rest of the primaries on the underwing of the Red-legged Kittiwake.

Red-legged Kittiwake, Bering Sea, 4 October 2009.

This shot shows all the features of the Red-legged Kittiwake: uniform slaty upperwing with contrasting white trailing edge; grayish underwing; the small billed, large-eyed, “cute” face; and the red legs (barely visible underwater). See Howell and Dunn (2007) for more information and photos of Red-legged and Black-legged Kittiwakes.

• Cambell, W. R., Sealy, S. G., Wahl, T. R., and Walker, R. P. 2008. Status of Red-legged Kittiwake (Rissa Brevirostris) in British Columbia with notes on its occurrence in Canada and the Continental United States. Wildlife Afield 5: 3-11.
• Gibson, D. D., and Byrd, G. V. 2007. Birds of the Aleutian Islands, Alaska. Nuttall Ornithological Club and the American Ornithologists’ Union. Series in Ornithology 1.
• Howell, Steven N.G., and Dunn, J. 2007. Gulls of the Americas. Houghton Mifflin.
• Isleib, M. E., and Kessel, B. 1973. Birds of the North Gulf Coast-Prince William Sound region, Alaska. Biol. Papers Univ. Alaska 14.

I just returned from 12 days of birding in the village of Gambell on St. Lawrence Island with Wilderness Birding Adventures. Our fall tour was conducted from September 1st through the 7th, after which a few of us stayed on longer to see what else the island might produce.  As it turned out the bulk of the excitement occurred during our first three days on the island.  Without question the highlight of the trip was the discovery of both Pallas’s and Yellow-breasted Buntings on September 2nd.  There are about 5 previous North American records for each species, all from Alaska.  Late on September 5th the winds switched to north and remained there more or less for the rest of our stay making the birding a bit slow.  The first few days of rarities, however, more than made up for the slow ending to the trip.

Juvenile Pallas’s Bunting Emberiza pallasi, Far Boneyard, Gambell, 2 September 2009.  More photos here.

Yellow-breasted Bunting Emberiza aureola, Far Boneyard, Gambell, 2 September 2009.  More photos here.

Fresh out of the bath, the bird appears a bit bedraggled.  In over seven hours of attempting to get good looks of these two skulking buntings, this was the only time that I saw the Yellow-breasted Bunting on the ground and completely in the open.  With a bit of diligence and fortitude everyone in the group eventually got great views of both buntings.

Black-headed Gull Croicocephalus ridibundus, Troutman Lake, Gambell, 5 September 2009.

Its larger and more robust build, thicker bill, darker legs, less extensive hood, and under-wing pattern separate adult Black-headed Gulls from the somewhat similar Bonaparte’s Gull.

Female-type Common Rosefinch Carpodacus erythrinus, Far Boneyard, Gambell, 1 September 2009.

Common Rosefinches have a strongly curved culmen and an unmarked face, giving them a blank-faced and beady-eyed look.  Of the three other North American Carpodacus finches female Common Rosefinch is most similar to female House finch (which also have a curved culmen and plain face) but can be separated by voice, range and possibly by the slightly blurrier breast streaking of the House Finch.  However, there is very little information in print (none?) on separating House Finch and Common Rosefinch, and no region where they have ever overlapped in range.  While House Finch is extremely unlikely at Gambell, it has strayed to southeast and south coastal Alaska and is listed as casual on the state checklist.

This individual had especially warm plumage with the rump appearing warmer brown than the rest of the upperparts and the flight feathers showed warm, slightly greenish tones.  The only other Carpodacus recorded from St. Lawrence Island is Purple Finch for which there are three records. Click here for discussion on the identification of the other Carpodacus finches.

Female Brambling Fringilla montifringilla, Far Boneyard, Gambell, 3 September 2009.

This female Brambling spent a few sunny hours catching flying insects in the far boneyard. It was found in the afternoon and not seen in subsequent days.

Juvenile Red-necked Stint Calidris ruficollis, Gambell, 4 September 2009.

Getting a bit late for most shorebirds at this latitude, this Red-necked Stint tied the late date record for the island.

“Asian” Barn Swallow Hirundo rustica rustica, Gambell, 4 September 2009.

Two races of “Asian” Barn Swallow occur as vagrants to Alaska–rustica and gutturalis. This individual probably represents rustica because of the complete and thick blue breast band.  The North American subspecies eurythrogaster, which has an incomplete breast band and a reddish belly, regularly breeds no closer to St. Lawrence Island than Cordova in Prince William Sound, Alaska.  This bird arrived at Gambell on the 3rd and was seen at widely scattered locations around town.  It was not seen perched until the evening of the 4th when it cooperated for about 30 minutes before disappearing.

Juvenile Gray-tailed Tattler Tringa brevipes, Troutman Lake, Gambell, 3 September 2009.

Both species of Tattler are rare but regular fall migrants at Gambell.  The heavy spotting on the upperparts, especially the tertials and great coverts, and the pure white flanks identify this bird as a juvenile Gray-tailed Tattler. The wing coverts of Gray-tailed Tattler also show faint brownish-gray tones.  Juvenile Wandering Tattlers show more blueish-gray tones.  The distinctive two-note “too-weet” call is diagnostic for the species.  For more photos of juvenile Gray-tailed Tattlers and a side-by-side comparison with juvenile Wandering Tattler click here.

Juvenile Red Phalarope Phalaropus fulicarius, Corner Marsh, Gambell, 7 September 2009.

Red Phalaropes are regular migrants past Gambell in the fall and we encountered several hundred each day we were there.  This bird is beginning to acquire its winter garb in the form of grayish scapular and mantle feathers.

Just a quick note from Gambell to post these photos of two great birds, present together!  They were here only yesterday in the far boneyard at Gambell!  When I get more time on-line (too much time birding to post much) I’ll post photos of Brambling, Common Rosefinch, and hopefully much more to come.

Yellow-breasted Bunting Emberiza aureola Far Boneyard, Gambell, 2 September 2009.

Pallas’s Bunting Emberiza pallasi Far Boneyard, Gambell, 2 September 2009.

This bird is believed to be a juvenile because of the overall rufous tones especially on flight and tail feathers, and the streaking on the breast, crown and rump.  Comments from anyone familiar with Pallas’s Buntings would be most welcome!

The ship moved into Bristol Bay a few days ago where the highlight has been an early Sabine’s Gull on 28 April.  The bird numbers dropped dramatically after we left the deep waters west of Bering Canyon and entered the shallower waters of Bristol Bay.  However, the last two days transiting deep water (26-27 April) were great and produced 2 more Mottled Petrels and 2 Leach’s Storm-Petrels–both of which are exclusively found over deep water.  We also recorded 4 Red-legged Kittiwakes on this transit.  There have been nice numbers of Short-tailed Shearwaters, both over deep water and in the shallower waters of Bristol Bay.  Many of the shearwaters have been occurring in tight flocks of 30-50.  Watching Short-tailed Shearwaters maneuver in a 30 knot wind is about as good as it gets!

Short-tailed Shearwaters Puffinus tenuirostris in Bristol Bay, 29 April 2009.

When compared to the similar Sooty Shearwater, note the steep forehead and shorter, thinner bill of the Short-tailed.  Contrary to popular belief the “underwing flash” of a Sooty is not a reliable field mark for separating the two species.  Short-tailed Shearwaters can show a flashy underwing (see top photo), especially when seen in bright light as these birds were.  On a Sooty Shearwater, however, the brightest part of the underwing is the underwing covert panel and these bright underwing coverts contrast with the bird’s darker flight feathers.  The underwing of a Short-tailed Shearwater is more uniform and can range in coloration from dark to light.  When Short-tailed Shearwaters show a pale underwing it is a uniformly pale, or “flashy,” underwing and the flight feathers, especially the primaries, are also pale.  In the top photo of the two Short-tailed Shearwaters note how the paleness of the underwing extends onto the primaries, which don’t contrast with the under-primary coverts as they would in a Sooty.   Structural clues and flight styles are also extremely important, especially when the two species are seen together.

Click here for an excellent article (with excellent photos) by Greg Gillson, published in Birding magazine, which details the seperation of these two species.