Hybrid Gulls

 

Years ago, Lesser Black-backed Gulls were rare in Virginia and now they are quite regular throughout the year. In eBird there is now even a pull-down menu choice for the hybrid Herring Gull X Lesser Black-backed Gull, as that interbreeding is known to occur. The two species are commonly found together. While it would take DNA analysis for actual proof, providing eBird records for this and other suspected hybrid types does help to increase our awareness and understanding of interbreeding among species.

In the above photos, the 3rd bird from the right in front is a suspected Herring X Lesser because the mantle color is clearly intermediate between Herring and Lesser. It stands out as markedly different. It's head is tucked and legs are hidden, but there is so much variability in those features, that if shown, it wouldn't really add much. What's very lucky here is to have the various species side-by-side, because, as we know, lighting and angles can distort colors. A bird like this all by itself would be nearly impossible to judge.

The top shot shows part of a group of 22 Lessers and dozens of Herrings I saw together in southeastern Virginia in late February. There are few Virginia records in eBird for this suspected hybrid, some without photos or details, though birders should be aware of such possibilities and document as much as possible, to add to our knowledge.

Brian Taber

Juncos With Wingbars

"Slate-colored" Dark-eyed Juncos very rarely can show white wingbars, so 4 juncos together at my feeder this week in James City County showing wingbars was a noteworthy event. 

The top 3 photos show the same bird white wingbars on both greater and median coverts, some pale edging on tertials and overall pale gray plumage with contrasting dark loral area that's most evident in the 3rd photo down. In the images with the bill closed, the bill appears larger than those of the other juncos.

The 4th photo down shows another with 2 wingbars, but is a different bird from the other with 2 wingbars, due to its weaker wingbars, presence of a large amount of brown in the primaries, a pale brown back and crown and interestingly, a more convex-appearing gray border on the lower breast, with even darker markings below a slightly paler throat. "Oregon" Dark-eyed Juncos show a more convex lower border there as well, often with very dark shades.

The 5th photo down shows a bird with several white tips to just the greater coverts and white edging to the tertials, overall pale gray plumage with a darker loral area and faintly streaked brownish back.

The 6th photo down is of a very striking bird with a dark-streaked brown back contrasting with blue-gray head, whitish tertial edges and a broad white wingbar on the greater coverts.

The "White-winged" sub-species of Dark-eyed out west looks very similar to the birds shown here, as seen in many eBird reports from Colorado...some show bolder wingbars, others quite faint and there's variable bill color. Photo images change, of course, with different lighting, including bright snowy backgrounds, making the gray tones appear variable. Some show grayer bills, others pinkish. There are 3 white outer tail feathers in "White-winged" and usually just 2 in "Slate-colored," a feature which can't easily be checked unless the bird is in-hand or there's a very lucky photo.

"White-winged" can stray eastward, as 2 were banded and examined closely for tail feathers and other features on Oct 24, 2020 in Pennsylvania, as seen in eBird.

Comments welcome at taberzz@aol.com.

Brian Taber