Subject: What subspecies of Sky Larks?
Date: Dec 31 23:42:13 1998
From: bboek at olympus.net - bboek at olympus.net


Tweeters,

On 12/21/98, Patrick Sullivan and I found a couple Eurasian Sky Larks on the Sequim-Dungeness CBC, apparently the first time that this species has been located on the mainland in Washington. They have been viewed by several others several times since, west of the town of Dungeness in a field on the north side of East Anderson Road, about 0.2 miles east of the intersection of East Anderson and Clark Roads (or 0.8 miles west of the Dungeness River). They were last viewed on 12/30. Ruth Sullivan has taken some exceptional photographs of the birds, which we hope to have available for viewing before long on someone's web page.

I am putting the description of these birds on Tweeters because we have a problem determining the subspecies of these birds; specifically, are they the nominate subspecies, as was introduced on Vancouver Island, or are they a migratory Asian subspecies, as has shown up in California and Alaska? Many of us who have seen the Sequim birds feel they look more like the pekinensis subspecies illustrated in the National Geographic field guide, but our experience is not enough to say one way or another.

I am hoping that someone familiar with the Saanich Peninsula birds can give us some clues about the similarities or differences between the Sequim birds and the ones on Vancouver Island or San Juan Island. Is there someone out there in Tweeterdom who has experience with the Vancouver Is. birds? If so, we need your help. Is there anything about the Vancouver Island birds that does or does not fit our description? We are also sending copies of Ruth's photos to Joe Morlan, who wrote a paper about the Sky Larks observed in California.

Thanks,
Bob Boekelheide
Sequim

ACCOUNT AND DESCRIPTION OF EURASIAN SKY LARKS SEEN ON SEQUIM-DUNGENESS CBC, 21 DECEMBER, 1998

During the afternoon of our CBC, while walking a large weed field and neighboring mowed hayfield in west Dungeness, WA, between Marine Drive and East Anderson Road, Patrick Sullivan and I scared up a flock of 12 Western Meadowlarks plus two other birds that we could immediately see were not meadowlarks. We clearly saw that these birds had bright white outer tail feathers and heard a chirrip call note when they flew. We chased them for several minutes, but these birds would not sit long enough for us to get a reasonable view. They repeatedly flew up quickly in front of us, flew ahead of us and circled for several hundred feet, then settled abruptly into the grass. Only once on CBC day did we observe them very briefly on the ground, seeing that they appeared streaked on their backs, with streaky upper breast with tawny buffy undercoloring, and very white bellies. At the time we were somewhat uncertain of their identification, and, in the haste of the CBC, we tentatively identified them as Horned Larks, the most likely candidate in this habitat, and continued with the count.

After our compilation, and into the next day, these birds still troubled me. Horned Lark clearly didnt fit. Michael Willison and I returned to the weed field the next day, found the birds, and again chased them several times as they flew ahead of us and settled in the grass. We again had very brief views of the birds on the ground, but we were able to see them better in flight. They clearly showed a white trailing edge to the secondaries and perhaps the first couple primaries, which stood out when they took flight and spread their wings.

Using these details, and by piecing together various field marks, I determined that these birds were actually Eurasian Sky Larks. Everything about them fit Sky Lark, except that we had never seen them raise their crowns as described in numerous field guides.

Patrick and Ruth Sullivan, Bob Norton, and I met the next day, 12/23, at the weedfield.
This day we had much better views of the birds on the ground, although they were still very flighty. Ruth Sullivan took pictures of the birds on the ground and in flight. Everyone agreed that these were clearly Eurasian Sky Larks, although now the question was whether these birds were waifs from the introduced populations on Vancouver and San Juan Islands, or whether they were vagrant migrants from Asia. Later, on the 26th, we obtained the best views of all, as several of us viewed both birds on the ground for several minutes and Ruth Sullivan obtained remarkably good photographs. These times we saw the birds erect their crests numerous times.

Description:

Size: One reason why I did not initially think these were Sky Larks was because they appeared larger than I thought Sky Larks should be. They were about Horned Lark size in length, yet they appeared fuller bodied than Horned Larks. Their white bellies stood out as being larger and more rounded than the leaner look of a Horned Lark.

Head: Crown streaked with dark and light warm brown lines extending from forehead to nape. Dark line through eye with lighter-colored (but not white) superciliary line extending far back on face, well past the rear edge of the auricular patch. The auricular patch was very distinct when we observed the birds on 12/26, forming a dark brownish triangle on the side of the face enclosing a lighter brown patch within. The superciliary extended far back enough to meet a lighter line coming up from the throat -- this gave the bird a distinct facial patch looking somewhat like that of an immature Lark Sparrow, or like a Clay-colored Sparrow.

We did not see the birds erect their crests on either 12/21 or 12/22, but on both 12/23 and 12/26 they did this several times. Ruth Sullivan captured this well in her photographs on 12/26. Originally the crowns appeared rounded, but this changed when the birds erected their crests, giving them a peaked look.

Eye: dark, with a hint of a lighter area around the eye, but not really an eye ring.

Throat: whitish, with hint of buffy. Definitely not streaked.

Underside: Upper breast with buffy background wash covered by distinct dark streaking, starting fairly abruptly below the white throat. This struck me as being very similar to a Lincolns Sparrow, with distinct streaky on top of buff. The buffiness and streaking cleanly stopped on the lower breast, changing to very white lower breast and belly. The white belly and undertail coverts stood out especially in flight. The flanks appeared to have a very slightly buffy wash just below the wings, but the central belly was very white.

Back: Very streaky, with very dark brown feathers radiating in lines from the upper back down to the mantle. I initially thought these dark brown feathers had black centers, but when I saw the birds very well in good light it looked instead as if they were very dark brown, not black. At times the feathers appeared scaly, with lighter borders surrounding the darker centers, but at other times the feathers overlapped into very distinct radiating lines of dark chocolate brown. In certain light the background colors to the back, such as on the feather edgings, appeared almost golden brown, but in more subdued light these golden colors faded to plain brown.

Wings: There were no distinguishing marks on the wings when they were folded, other than a slightly paler area across the coverts in mid-wing. This did not make for a distinct wing bar, just a slightly lighter area across the wing. When the birds flew, they showed a very white trailing edge to the secondaries and possibly the first couple primaries.

When folded, the wingtips extended about one fourth of the way down the tail, to about the end of the upper tail coverts.

Tail: Bright white outer rectrices, showing very clearly in flight. The center rectrices appeared dark and unmarked. The white on the outer rectrices clearly extended the length of the tail, unlike that found on longspurs. The tail appeared relatively straight across the margin, neither notched nor rounded. I commented to myself once how the tail almost looked like the tail on a Western Kingbird, but with even more white along the sides.

Bill: Slender, straight bill, clearly not conical shaped. The bill was proportional to the birds head, not overly long or wide. Color appeared somewhat dull yellow-gray.

Feet: Appeared pinkish-orange in color, the one time I saw them well.

Voice: The birds called just about every time they took flight. Their call note was an abrupt, fairly low pitched chirrip or birrup, repeated quickly one or two times each flight. In retrospect, this call note clearly excluded Horned Lark, but we did not question this on CBC day.

Behavior: The birds were first found with a flock of 12 Western Meadowlarks. When disturbed, they were very different than the meadowlarks, which usually flew short distances and landed again. When the Sky Larks took flight, however, they flew for several hundred feet, typically flapping quickly for several strokes, then briefly taking a pause in flight, then flapping quickly again. This did not make for an undulating flight, but more of a flapping flight with occasional pauses.

The Sky Larks usually flew up to an altitude of 20-30 feet, continued at that altitude for several hundred feet, sometimes circling the field, then quickly descended and landed abruptly in the grass. The times that I saw them land while viewing with my binoculars I saw that they ran short distances after landing. They did not always stay together; in fact, on 12/26 we thought that one bird had disappeared, until after about an hour of chasing them the second was rediscovered near where the first had landed.

At this point, I feel there is no doubt that these two birds are Sky Larks. The question now is which subspecies are they -- the introduced arvensis, like those on Vancouver Island, or vagrant pekinensis, such as has shown up in California and Alaska? Two days prior to the first sighting, on 12/19, we had very strong northerly winds, which could possibly have driven Vancouver/San Juan Island birds in our direction. There are some characteristics of the birds, however, that may suggest pekinensis, such as 1) warm, occasionally goldeny-brown plumage, in contrast to the reputed plain brown plumage of arvensis, 2) the darkness of the streaking on the back, 3) the lack of any streaking in the throat, and 4) the distinct face pattern, with superciliary line extending far back on face and clearly outlined auricular patch.

Again, can anyone from Victoria or somewhere else who knows the Saanich Sky Larks give us a hand with this problem?