13 March 2009 Posted by Cameron Cox | 10:54 AM -

Small gulls

Those who have read my blog posts realize I have a soft spot for gulls. I most enjoy large gulls, but I won't say no to a gorgeous small gull if the opportunity presents itself. For the past month or so the opportunity has presented itself right in Cape May.

February and March tend to be the best months for seeing Black-headed Gulls and Little Gulls around Cape May. Therefore it was no surprise when a Black-headed Gull showed up in early March. Since then there have been 3-4 Black-headed Gulls and a Little Gull present at one time or another in Cape May or along the Delaware bayshore. I was lucky enough to see Black-headed Gulls several times, even two together, but my luck did not extend to the Little Gull.

This adult Black-headed Gull joined a group of Bonaparte's Gulls I was watching at dusk. I barely had enough light to take photos, though the low angle of the last rays of sunlight did give the bird a pleasing warm glow. While this would not be considered an example of good photography by most, I kind of like it.

While very similar to Bonaparte's Gulls, adult Black-headed Gulls are about ~15% larger and have an extensive black patch on the underside of the primaries that is visible in the photo above. They also have a longer, red-based bill unlike the short, all black bill of Bonaparte's Gull. One of the more striking differences is the beautiful, coral red legs of Black-head Gull compared to the dull pink legs of Bonaparte's Gull. In fly Black-headed Gulls tend to fly more like a Ring-billed Gull with smoother wingbeats that seem to emanate from the inner part of the wing, not the choppy wingbeats that come from the tips of the wings like a Bonaparte's Gull.

Adult Black-headed Gull (right) with an adult Bonaparte's Gull. Black-headed Gull is primarily an Old World species to which it is closely related. It fills a somewhat similar ecological niche as Bonaparte's Gull, though not an identical niche as Black-headed Gull is far more urban than Bonaparte's Gull. You are likely find them begging for handouts at local parks in Europe. The source for the Black-headed Gulls we see in North America is a breeding population in southern Greenland and a small population that breeds in Newfoundland. Black-headed Gulls have also bred in other scattered locations in North America, particularly in the north east and around the Great Lakes. The larger Siberian subspecies is a regular migrant in small numbers in western Alaska, I saw a several on St. Paul last summer, and occasionally along the Pacific coast in winter.

Here is a shot of a group of Bonaparte's Gulls taken earlier the same day. Notice the almost completely white underwing, small, dark bills, and pink legs. Also Bonaparte's Gull averages more gray on the nape than Black-headed Gull.

It is always good practice to look carefully through flocks of Bonaparte's Gulls for bonus in the form of a Black-headed Gull or Little Gull. These species are almost always found in the company of their New World cousin. Good luck.

All photos taken with a Nikon D200 and 300mm Nikkor lens.

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