24 June 2004
Green River, UT
Daniel S. Cooper
Background: On 23 June, I was driving from Denver to Los Angeles on I-70, and decided to stop for the night at the next promising-looking area for birding, and bird the next morning. I ended up in Green River, Utah. I started at 7:00 am the next day (24 June), checking the state park and then driving the farm roads in the agricultural area north of town, stopping at groves of trees and accessible riparian areas. At around 9:00 am, I pulled off at an irrigation drain crossing beside an alfalfa field that hadn’t been cut, hoping for a Bobolink or a Grasshopper Sparrow. My attention was quickly diverted by the distinctive song of a Gray Catbird from the vegetation behind me. I pished for a minute, and a second catbird mew-ed from the scrub about 20 meters away. At least one Yellow-breasted Chat was also singing. While waiting to get a better look, I realized that a third species was vocalizing, a much simpler song than either the chat or the catbird. It didn’t take me more than a second to place it as a White-eyed Vireo, a species I’d seen and heard many times in the southeastern U.S.
I pished on and off for about 20 minutes as the bird sang more or less continuously from the dense vegetation below me (I was standing on a levee road), and when it just wouldn’t come out, I decided to scale down the levee side and into the tangle. I quickly located the bird from about 15 feet away as it perched and foraged at around eye-level in a Russian Olive. I was able to get a virtually unobstructed view, and confirmed its identity.
Location: Roughly 2 miles north of the main east-west street of Green River, along Long St. The bird was in riparian vegetation (mainly Phragmites, Russian Olive, Tamarisk) in a sump on the outside of an irrigation drain that crossed underneath Long St. just north of a dog-leg turn. Black with orange-lettered “No Trespassing” signs were posted on posts on either side of the levee-top road. Small groves of Fremont Cottonwood and Chinese Elm were adjacent to the drain, and irrigated agricultural fields (corn, alfalfa) were nearby.
Duration of observation: Audial: c. 30 minutes. Visual: c. 1 minute. It was getting very hot, and though I was able to observe the bird by climbing down the levee side so that the trees were blocking out the sun (which was behind but well above the bird), it was still uncomfortably warm down in the tangle.
Distance: c. 15 feet away.
Size: A small passerine, similar in size to a Hutton’s Vireo, with roughly similar proportions.
Bill: Thick for a warbler, and generally “vireo-like”, with a distinctive short hook at the tip of the upper mandible. All-dark.
Eye: Distinctly pale whitish with a black iris, starkly offset against facial color.
Head: Greenish, with thick, bright yellow lores extending up into fore-crown and over eye. Much more extensive than pale loral wash of Hutton’s Vireo or spectacles of “Solitary” Vireo, as if sloppily painted on by a broad brush. Pale throat.
Body, wings, and tail: Generally olive above, pale whitish below with pale yellowish on flanks; two whitish wingbars. Tail not seen well, but of medium length and with no noticeable markings.
Song: A loud, rich warble “book-ended” by sharp, single (and essentially identical) chip notes; totally distinctive and unmistakable. I hear this species to say Quick, gimmie a rain Check!, and this individual sounded like every other White-eyed Vireo I’ve heard, repeating this song about four times per minute. It would go quite for several minutes at a time, but then start up again, from the same general patch of vegetation. Several times, it put one of the “chip” notes in the middle of the song, similar to the way Bewick’s Wrens often mix up the order of their chips and trills. However, this was the exception, and the bird basically sang the standard “chip-warble-chip” song throughout the duration of the observation.
Behavior: The bird was active – not fidgety like a kinglet– but moving in short bursts from perch to perch, pausing to a few times to sing and then flitting to the next perch. It hover-gleaned once, but did not flick its wings or tail. It stayed within the same level in the same tree for the duration of the observation, and, based on where the song was coming from, didn’t move away from this spot for the 30 minutes I was with it. It didn’t seem responsive to pishing, but did move enough that I was able to get several good views through the branches.
Similar species: Nothing really sounds remotely like a singing White-eyed Vireo, but with chats, catbirds, and mockingbirds in the area, I wanted to track it down visually just to confirm that it wasn’t one of these just “stuck” on White-eyed Vireo for a half-hour. Seeing the bird clinched it, as no other small temperate North American passerine has that white eye, esp. offset by wide yellow lores. (note: the chat and the catbirds were imitating a wide range of species, incl. Common Poorwill, Western Kingbird, Western Meadowlark, etc. – but not White-eyed Vireo).
Observer experience: 20+ years of birding in California, plus birding trips throughout the U.S. Part-time leader for Victor Emanuel Nature Tours since 1997. I last saw (and heard) many White-eyed Vireos in Port Aransas, TX, in April 2003, and have encountered it dozens of times in Texas and Florida, and a handful of times in Massachusetts, where I lived for four years, and elsewhere. Often, it is the only bird singing on slow migration days in spring, and the song becomes background noise in scrublands in Texas and hammocks in Florida – a classic example of vocalization that’s sort of burned into your head so that you can pick it out anywhere, mainly because you’re trying to filter it out!
Optical equipment: Zeiss 10x40 binoculars.
Daniel S. Cooper
415 North Orange Grove Ave., #15
Los Angeles, CA 90036