Annotated checklist and data resource
text © Don Roberson
photos copyrighted by photographer(s) credited
all photos taken in Monterey County, California
Yellow-throated Vireo Vireo flavifrons
Yellow-throated Vireo is a rare vagrant in Monterey County; records are split rather evenly between spring and fall vagrants along the coast, but two individuals summered (or attempted to do so). Four of the 8 records through spring 2004 were at the Big Sur R. mouth, including three singing males between mid-May and mid-June. This photo (left) is of one of those birds, captured and banded by BSOL on 20 May 2004 [photo © Ventana Wilderness Society]. It provided the 8th MTY record.

This photo of a spring male shows many of the classic features of Yellow-throated Vireo:

  • bright yellow 'spectacles' [eye-ring and lores]
  • bright yellow throat and breast contrasting with bright while belly
  • green head and back but gray upperwing coverts (gray extends down scaps to rump and uppertail)
  • two prominent white wingbars (tips of greater & median coverts)
  • stout bill
Not shown in this shot is the short gray tail, bright white undertail coverts, and bluish-gray legs. Overall, Yellow-throated Vireo is a big-headed, short-tailed, heavy-billed vireo. The song recalls our nesting Cassin's Vireo with its "question-and-answer" pattern but the song is much burrier and slower, often with 3-5 seconds between each phrase.

Yellow-throated Vireo is a nesting species of the eastern United States, barely reaching southeastern Canada, that winters from south Florida and southeast Mexico to northern South America. It is a vagrant anywhere west of the Rocky Mountains but there are about 60 California records, of which two-thirds have been in the spring. Two have wintered in southern California.

This May 2004 vireo remained along the Big Sur River, singing from the tall cottonwoods and sycamores, through at least 24 May; it was photographed in the field on 23 May for what may be the only "field" photos of this species in the county (right; © Don Roberson). On 24 May it had joined mixed chickadee-warbler flocks by mid-day, and then was seen to drink from the edge of the Big Sur River and also bathe in the river right next to the BSOL bridge. [BSOL bands birds on the right leg, so you can't see the band in these shots.]
For many years the only MTY record was of a bird found dead, partially eaten by ants, on 23 Aug 1981 at Tierra Grande, about 7 miles up Carmel Valley. Jon Dunn had a tour group at this mostly chaparral site to look for things like California Thrasher when participant Mary Yegella picked up this dead bird. Dunn identified the bird and gave the specimen to Vern Yadon, then curator of the Pacific Grove Museum of Natural History, who prepared it. The specimen (photo below) shows the plumage of Yellow-throated Vireo but the eye sockets had been eaten out by ants and some of facial feathering damaged. The skin was also desiccated and dried up, making preparation difficult.
Given the mid-August date and the fact that the bird had been dead some time, it seems probable that this individual was attempting to summer locally. There are a couple summer records in southern California and (later) one in MTY (next photo).
It was 18 years after the dead Carmel Valley bird before MTY recorded its second Yellow-throated Vireo (right; in-hand photo at BSOL © Don Roberson). Big Sur Ornithology Lab (BSOL) captured this adult about 9 a.m. on 28 July, and held the bird long enough for several to arrive to view it in hand (e.g., Jim Booker, Rita Carratello, Bob Maurer, Don Roberson, Steve Rovell, Bill Rydell). Booker was able to age it as a first-summer bird ("SY" in banding lingo). A number of observers followed it after its release as it joined a flock of chickadees and bushtits along the Big Sur River, occasionally giving a very loud, harsh, husky scold.

This vireo remained along the Big Sur River near BSOL (about a mile from the mouth) for the next six weeks, and went through a complete molt. It was recaptured twice and on its final recapture on 17 Sep was in crisp, fresh plumage. Note just how ratty and worn the bird looks in the July photo, with its tail particularly bedraggled.

Fall birds are very bright and crisp; see the description following the list of records for an example [no fall bird has yet been photographed in MTY]. Pyle's (1997) Identification Guide to North American Birds describes this species as having one complete molt each year — on the summering grounds (Jul-Sep) — and a partial molt on the wintering grounds (Jan-Apr). Hatch-year birds have a partial molt soon after fledging but retain the juvenal wings and tail to the next summer.

Here is a complete list of MTY records of YELLOW-THROATED VIREO Vireo flavifrons

1 23 Aug 1981 Carmel Valley Mary Yegella; J.L. Dunn found dead; #PGNHM
2 28 July-17 Sep 1999 Big Sur R. mouth BSOL banded, Tenaya Gordon recaptured twice to 17 Sep
3 15-23 Oct 1999 Carmel R. mouth Don Roberson bright imm; details & sketch below
4 31 Aug-9 Sep 2000 Carmel R. mouth Jeff Barnum, Bill Hill, Rita Carratello et al.
5 17 Sep 2000 Big Sur R. mouth Chris Tenney details below
6 19 May 2001 Big Sur R. mouth Steve Rovell singing male; details below
7 8 June 2002 Big Sur R. mouth Craig Hohenberger singing male
8 20-24 May 2004 Big Sur R. mouth BSOL banded singing male; photos
The first fall record for MTY was found by Don Roberson at the Carmel River mouth 15 Oct 1999. His description follows, including his sketch that day with color pencils:
15 Oct 1999 at Carmel River mouth, MTY, California

Rita Carratello and I decided to meet late in the afternoon of this Friday to bird the Carmel River; shortly after arriving we ran into Bill Hill and Jeff Barnum. The four of us decided to look at the ‘Odello Lagoon’ so we took the rough trail up from the riverbed to the ‘Odello parking lot’ which leads to the open fields south of the sewage treatment plant. As we crossed this old parking lot next to the treatment plant, we came upon a flock of chickadees. I went to the west end of the lot to look through them. Very shortly thereafter I spotted a bird with wingbars and a very bright yellow breast in a live oak. I called out to the group that I had a “Blackpoll or better”  and then said “in fact, it's so bright it might be a Yellow-throated Vireo.” Bill Hill then refound the bird higher in the crown of the oak and stated “yes, I've got it, it's a vireo” and we were soon all have long & leisurely views of a very bright, crisp Yellow-throated Vireo. The flock was working toward the willows along the edge of the river and the vireo followed. We later had even closely and more nearly eye-level views in a willow. The flock included several Yellow-rumped & Townsend’s warblers, and bright Tennessee Warbler, along with the Chestnut-backed Chickadees. The vireo did not vocalize.

Description: A big-headed, short-tailed, medium-sized vireo -- this shape is really quite different from our usual vireos. The bird had a heavy, hook-tipped, vireo bill; black in color. Legs were rather thick and in good lighting were obviously blue-gray in color. A big blackish eye dominated the face, and it was encircled with a yellow eyering with continued over the lores as a yellow line to create prominent yellow “spectacles.”
   The vireo was rich green throughout the head and back, contrasting with a very bright yellow throat and breast. This yellow breast then sharply contrasted with clean white belly and undertail coverts. In good light we had great views of the rich green back that gave way to a sharply set-off soft gray rump. Upperwing coverts, remiges, and rectrices black. The median and greater wing coverts had sharply-defined white tips creating two white wingbars. The lower wingbar was very broad -- almost twice as broad as the upper -- and therefore very obvious; the upper edge was a bit “ragged” sending “teeth” of white upward along the edge of each feather (recalling White Wagtail on this feature, but less pronounced that the wagtail pattern).  All tertials & secondaries & outer rectrices were edged white; edgings on tertials broader than on the remiges/rectrices.
   This is the brightest Yellow-throated Vireo I've ever seen, so crisp and colorful. While the Yellow-throated Vireo that summered on the Big Sur River molted into a brighter plumage, it still did not look to me (and I saw it in September near the end of its molt) nearly as bright as this Carmel River individual. I suspect this bird is a first-year bird.

Status: This is now the third record for Monterey County. The prior two were adults that summered (or, in the case of the one found dead in August 1981, likely summered).

— Don Roberson, Pacific Grove CA

Addenda: this Yellow-throated Vireo was seen the next day (16 Oct) by Bill Hill, Jim Booker, and others, and on 17 Oct by Alan Eisner et al. It was thereafter seen daily to 23 Oct (last seen by Craig Hohenberger et al.).

Chris Tenney forwarded these details of his 17 Sep 2000 bird at Big Sur R. mouth via email:
"Here are the distinguishing characters i saw , based on notes and memory: unstreaked white belly, yellow throat, and yellow breast; dark wings with white wing bars; thick bill (compared to n. parula); yellow spectacles and lores. i didn't see the rump and back since i first saw the bird's underside, my first thought was that it might be the parula, but the spectacles and thick bill ruled that out. unstreaked underparts and thick bill also eliminate pine warbler.  also, i had just seen the other ytvi on the carmel river, so i had a good mental image of this species.”
Don Roberson wrote these details on 19 May 2000 regarding a singing male at Big Sur R. mouth:

"Sunny day with mild wind; birding with Rita Carratello, Dan Singer, Joe Morlan, Robbie Fischer, Steve Rovell and others. Yellow-throated Vireo: one male singing off & on in willows on south bank of Big Sur River, and also in sycamores; found at 6:30 a.m. by Steve Rovell. The bird is unbanded. We eventually got fine views.
   A mid-sized, big-headed, big-billed vireo with a fairly short tail that was usually held cocked-up. Bright yellow throat & breast contrasted with bright white belly; upperparts rather bright green. Dark eye surrounded by broad yellow 'spectacles' (eyering & loral stripe); wings dark gray crossed by two broad white wingbars (white tips to greater & median coverts). Tail grayish; brief view of rump and it looked pale gray.
   Bill heavy, obvious 'hook' to tip; black. Legs sturdy & thick, looked bluish-gray.
   Song recalled Cassin's Vireo but a bit slower so the cadence of 'question-asked, question-answered' less apparent, but could be mistaken for a Cassin's or Plumbeous song. Also gave 'eh-eh-eh' harsh grating call notes."

Joe Morlan has another description of this bird on his web site.

Use these links to reach other portions of the Monterey County list:

Part 1: Waterfowl through Grebes
Part 2: Albatrosses through Frigatebirds
Part 3: Herons through Cranes
Part 4: Plovers through Sandpipers
Part 5: Jaegers through Alcids
Part 6: Doves through Woodpeckers
Part 7: Flycatchers through Larks
Part 8: Swallows through Pipits
Part 9: Waxwings through Warblers
Part 10: Tanagers through Sparrows
Part 11: Grosbeaks through Finches
or just the plain Checklist (no annotations)
Readers may use this material for their own private enjoyment, study, or research but none of the photos or text herein may be used commercially nor may they be reposted on other web sites without written permission. All material is copyrighted. The posting of photos and text on this private web site is not a submission to review organizations.






Page created 23 May 2004, updated 24 May 2004