Listing Through Life

xema (a made-up word with no meaning) sabini (named for Joseph Sabine, English naturalist)

Tuesday, September 11, 2018 — 4:12 pm

Chatfield State Park, Colorado

Sabine’s Gulls breed high in the tundra along the Alaskan and Canadian coast of the Arctic Ocean. Most of them migrate along the Pacific coast, but every fall, a few show up on the larger reservoirs in central Colorado. I knew I would get one sooner or later.

One was found on Chatfield Reservoir earlier this week. I was planning on heading up this weekend, but then three jaegers — two Long-tailed and a Parasitic — were spotted at the same place, and I couldn’t let two lifers and a second-ever sighting go by.

I arrived at Chatfield State Park a little before 4:00 pm. I had no idea where any of the birds were being sighted, so I just started walking the shore, stopping frequently to scan the large lake with my binoculars and spotting scope. It wasn’t too long before I spotted a black-headed gull swimming in the center of the southwest arm of the lake.

I set up my scope and watched. Most of the time, the gull was swimming, looking back and forth alertly with its head held high. Occasionally it would flutter forward somewhere between three and 15 feet and then land again. I wasn’t close enough to see what it was chasing, if that’s what it was doing.

But I was close enough to see the diagnostic “M” wing pattern. As it’s the only gull with a black head and that pattern, I had my bird.

The photos are all stills from a video I shot by holding my phone up to my scope.

I continued down the shore and got a little closer to the bird, but it also put it in a direct line with the sun. At this point, it was swimming away from me, and I didn’t see it flutter again. When it turned its head, I was able on one or two occasions to make out the yellow tip on its black bill.

Later, on the other side of the lake, I spotted it, or another one, swimming along the face of the dam.

I chatted briefly with two other birders. I was pronouncing the name of the gull as SAY-beans. They said the first syllable with the “a” as in sad and the second syllable as bin, so SA-bins. This got me wondering, so I googled it and discovered that it’s supposed to be pronounced SA (as in sad)-beans. So we were both half right.

vireo (small green bird) cassinii (named for John Cassin, American ornithologist)

Monday, September 3, 2018 — 10:10 am

El Paso County, Colorado — Aiken Canyon Preserve

About 20 years ago, the former Solitary Vireo was split into three species. The eastern form, which I’ve seen many times, is called the Blue-headed Vireo. The southwestern form, which nests in Colorado, is now the Plumbeous Vireo. I’ve spotted several of them since we moved out here. The third form, Cassin’s Vireo, nests in the northwest and migrates through Colorado. It’s fairly rare in the spring, but much more common for a couple weeks in the fall. I’ve never seen one.

The plummage differences between the three species make things challenging. All have bold white spectacles and obvious wing bars. The Plumbeous is almost all gray, but with a touch of yellowish on the flanks in the fall. Cassin’s has more yellow on the flanks and sides and a wash of green on the back and wings.

On Sunday evening, I found a “Solitary” vireo along Monument Creek and got excited for a minute. But as I followed the bird through the scrub oak, I saw that it only had a bit of yellow on the flanks and was otherwise gray.

I went out again on Labor Day Monday morning, this time to Aiken Canyon Preserve. It was a cool, overcast morning, and I had the place to myself. I hadn’t gone far before it began raining hard. I took what shelter I could find in a clump of scrub oak, but was soon very wet. When the rain stopped 15 minutes later, I decided to continue instead of heading back to the car.

I climbed up into a rocky canyon with ponderosa pines and an understory of scrub oak and came upon a mixed flock of birds. Most of them were Pygmy Nuthatches, but I also saw Mountain Chickadees, a Wilson’s Warbler, a Yellow-rumped Warbler, three Western Wood-Pewees, and a “Solitary” vireo. This one had pale yellow all along its sides and flanks. It’s head was light gray, and its back had a greenish wash.

After getting a good look, I pulled out my camera and attempted to get a photo. It was moving fairly quickly through the lower branches of a pine. I lost sight of it, but found it again about two minutes later. Again I got good looks at the greenish back that contrasted with the gray head and the yellow sides. It flicked its wings a time or two while I was watching — I think I caught it mid-flick in a couple of the photos.

It was still a very gray day, and the bird was back-lit against the sky, so the color doesn’t really come through in the photos, although I can get a hint of the yellow sides.

It hopped from the pines into some scrub oak, and I lost it. I hung around for another 10 minutes, but didn’t spot it again. I suppose there were about four minutes from when I first saw it until it disappeared.

larus (rapacious seabird, gull) canus (gray)

Sunday, August 19, 2018 — 2:00 p.m.

Cherry Creek State Park, Colorado

It doesn’t get a lot easier than this. Last night I saw a Colorado birding page on Facebook that somebody found a Mew Gull in second-summer plumage at Cherry Creek State Park. They posted several photos, linked to a map showing where exactly in the park it was seen, and mentioned that it was missing several tail feathers and, therefore, probably couldn’t go far.

I drove up on Sunday afternoon, parked by the marina, and looked for a flock of gulls. There were about 50 along the shore beneath the dam in the extreme northwest corner of the lake.

I was distracted for a bit by the several Snowy Egrets and Black-crowned Night-Herons that were wading with the gulls. But as soon as I started searching for the Mew Gull, I found it. It’s the bird closes to the camera in the photo above. It swam around the area, just off the beach for about 10 minutes while I watched, then headed in and stood in shallow water for about three minutes. It then went for another swim before coming back in and standing at the water’s edge about 10 feet from where I stood.

As you can tell from the photos, its back end looked decidedly chewed-upon. Either something (hawk? dog?) grabbed it, and it managed to get away, or it happened to molt a whole lot of important feathers at once.

The Mew Gull i.d. marks are it’s small size compared to other white-headed gulls, its round head with a gentle look, its small bill with a black tip, its grayish legs, and the fact that the few remaining tail feathers are brown and not black.

Here it is swimming next to a Ring-billed Gull for comparison. Note that the Ring-bill is larger, with a more substantial bill that’s pink at the base. Also, the Ring-bill tail feathers have black on them, not brown.

And here it is next to a first-year California Gull.

Mew Gulls breed in North America throughout most of Alaska and northwestern Canada. They winter along the Pacific Coast. But every year, a handful show up on larger lakes in Colorado. I had determined to go for it the next time I saw a report. It turned out to be a lot easier than I’d expected.

Other birds I saw at the park this day. An immature Black-crowned Night-heron with two Snowy Egrets in the foreground and three California Gulls in the background.

More Snowy Egrets

And in the cottonwoods in the wetlands at the south end of the park, a Great Horned Owl.