Vesper Sparrows arriving (slowly), please watch for banded birds

[Joel Geier]

"Oregon" Vesper Sparrows (belonging to the subspecies that nests in western Oregon and western Washington, proposed for listing under the Endangered Species Act) have finally started to show up in our area, about two weeks behind typical first arrival dates from recent years.

Bob Altman and I have been checking local monitoring sites since around March 25th, with no luck until Sunday (April 9th) when Bob found four birds on private land in southern Polk County. At least three of those birds were color-banded, as part of an American Bird Conservancy project that Bob has been leading for 6+ years now.

Typically the first birds to arrive each spring have been "older" males (in sparrow terms, "older" means "after-second-year"), and this year seems to be continuing that pattern, despite the overall delay. One bird that hatched in 2021 turned up at its natal site after not being seen there last year (which is kind of unusual, as site fidelity is quite high, but we've seen this occasionally).

I saw another Vesper Sparrow (not banded) in north Benton County today. I see from eBird that on April 9th Kaplan Yalcin also spotted a couple of Vesper Sparrows in Linn County south of Brownsville, one of the other areas in the Willamette Valley that still has a significant nesting population. We don't have any banded birds in that area, so -- again given the very high site fidelity -- it would be a big surprise to see a banded Vesper Sparrow in that area.

However for birders in Benton or Polk County, please keep an eye open for any banded Vesper Sparrows. The most likely locations to see Vesper Sparrows from public right-of-ways would be at Bald Hill Farm (on the west side of Corvallis), or some of the Christmas tree farms along Bellfountain Road (south of Corvallis) or near Airlie.

A little later in the season, there could also be banded birds along the Cardwell Hill Trail (especially the west end near Wren, and secondarily up on Fitton Green Natural Area), though those sites are at higher elevation and tend to be vacant until things really warm up, later in spring.

If you do see a banded bird, please try to get a photo, or a description of the bands. I'm attaching a photo key to our most common band colors (we've added a couple other weird ones since then), and a photo of what these look like on a banded bird. Please try to note down the colors (top and bottom, left and right legs). Normally there will be a plastic color band above a standard metal band on the right leg, and two different plastic color bands on the left leg. Some of the colors can fade after a year or two (for example, red bands start to look like orange), and shadows can also be tricky. So if you're not 100% sure of the color, please say so.

Most of these birds nowadays are on or adjacent to private property where we count on the goodwill of the property owners, both to maintain the habitat and to provide access for research. So please respect private property boundaries, even if it means not getting a full view of the band colors. In most cases we have agreements for private-property access, so we can follow up once we know that a "bird of interest" could be around.

Thanks, and meanwhile happy migration!

Joel

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Joel Geier

Tampico neighborhood north of Corvallis