Gull big day

ring-billed and mewMy recent gull class field trip found ten species of gulls (Western, Glaucous-winged, Glaucous, Herring, Thayer’s, California, Ring-billed, Mew, Bonaparte’s, and Heermann’s). This was a new record for the class, and it got me wondering. How many species of gulls could one conceivably find in one day in Oregon?

The best time for such a quest would be early November. By then, the wintering species would be here, and there are usually a few lingering Heermann’s Gulls that haven’t gone south yet. Bonaparte’s Gulls are migrating south at this time, as well. If you waited until December, the migrants would have already moved on. By late January, many of the wintering birds have already left.

The best location for a gull quest would be the coast. Eight species regularly occur in the Willamette Valley as well, (Western (rare), Glaucous-winged, Herring, Thayer’s, California, Ring-billed, Mew, and Bonaparte’s), but anything else would be extremely rare. Ring-billed can be challenging to find on the coast, but you can usually find one among the Mew Gulls in the estuaries. So with some searching, you could count on these eight species, plus Heermann’s makes nine.

If your quest occurred the day after an autumn storm, you would have a chance at two pelagic species, Black-legged Kittiwake and Sabine’s Gull. That would bring your total to eleven.

To exceed eleven species, you would need to find a rarity. Glaucous Gull is probably the most likely. Other less likely candidates include Lesser Black-backed, Slaty-backed, or a wayward Franklin’s.

So if you could find a rarity (or go see a previously reported bird) and timed your quest to coincide with some west winds, you could conceivably see twelve gull species in a day. Has anyone done this? This sounds like a noble quest to me.

Gull Gallery

Portland’s Westmoreland Park is a great place to find a variety of gull species during winter. Seven species and one hybrid are regular, and there is always the possibility of something more unusual showing up.

California Gull:  medium-gray mantle, long dark wingtips that extend well beyond the tail, long straight bill with both red and black gonydeal spots, yellowish legs and feet with blue-gray cast.

Ring-billed Gull:  smaller size, neat black ring around bill, long dark wingtips, yellow legs and feet.
Here’s the Ring-billed Gull at rest. Note the fine streaking on the head and the red orbital ring.

Mew Gull: petite yellow bill, round head, long wing extension. These small gulls will mix with the Ring-billed flock, but generally don’t mix with the larger gulls.

Glaucous-winged Gull:  Note the lack of contrast on this bird. The short wingtips are the same color as the mantle. The head and upper breast are covered with an even blurry mottling. The only parts that don’t blend in are the pink legs and feet.

Western Gull:  large size, dark gray mantle, short black wingtips, never any marks on the head – even in winter. This species is much more common on the coast, but a few make it in to the Willamette Valley in winter.

Western Gull X Glaucous-winged Gull hybrid (Olympic Gull):  an even blending of characteristics of both parent species. The mantle is darker than a pure GW, but Westerns never show this much mottling on the head and neck.  The wingtips are dark, but not actually black. You can tell this is a third cycle individual by the tiny bit of black on the tail and by the odd pattern on the bill. These hybrids show a great deal of variation, and are often the most numerous gulls in the area.

Herring Gull:  sloping forehead, pale eye, bill not too thick, black wingtips that extend beyond the tail.

Thayer’s Gull:  rounded forehead, thin bill, dark eye (usually, not always),  long black wingtips with much more white on the underside.