Thursday, November 27, 2008

Gulls 101

Tis' the season of GULLING (to observe and ID gulls)

Late November is the best time to examine your local landfills for odd gulls. Hunting season is coming to an end, and there is a lot of meat scraps from the deer, and other animals at the landfill. Of course, not just any one can have a superb Gullery near them. You need a landfill, and a large body of water, say a reservoir, or a lake, or the ocean.

Now, Gulling isn't for the faint of heart (or nose). Gull ID can be tricky, but once you catch gull fever, it will be all you can think about. You will love to smell the landfill in the cool morning with the high tempereature reaching 20 dergrees.

Lets break down the numerous Gull species to look-a-like groups, and first Ring-billed, California, Mew Gull.

The Ring-billed Gull is the most commen gull in North American. The common parking lot "seagull". Most everyone can ID a Ring-billed, but what about the ones that look like Ringbills.

The Mew Gull is a Pacific Coast bird, but often is seen in the interior states. It is smaller then the Ring-billed in build, and bill size. Just looking at is, you can see the real "petite" face, with the small, usually unmarked bill (juveniles thru second winter have dark markings on bill) Their back coloring slightly darker, and they have marginally longer wings. The winter adults have very heavy mottling on the head, and neck. It's softer looking, and more difuse then the marks on the winter adult Ring-billeds. The dark eye is always good to look for. Most Mew Gulls have a dark eye in every age, and plumage cycle.

Adult Mew Gull with Ring-billed Gulls

The California Gull is a little larger then the ringbilled, and has a heavier look. In adults, they have a darker back that can be seen from a distance. Their bill has the black "ring" as the ringbills have, but also a red spot at the lower end of the "ring". The juvenile birds are darker brown all over, as compaired with Ringbills.

California Gull with Herring Gulls

Next group is the Thayer's/Kumlien's, and Herring Gull group.

The Herring Gull is the common "large" light backed gull. It was pale pink legs and a pale eye. It has black wingtips at all ages. It has a relatively large bill, and "heavy" body.

Variation in Herring Gulls (spot the other species!)

Now, Thayer's Gulls can be tricky because of the Iceland/Kumlien's Gull complex. Overall, Thayer's Gulls are smaller billed, and have a more delicate build. Herring is more big, and powerfull. In winter adults, the Thayer's Gull has heavy mottling on the head and neck. Now some Herring Gulls have this, but with size and shape plus other field marks, can easily be told apart. The Thayer's Gull has a dark eye in all ages. The pink legs tend to be a bit brighter, but not a good ID point. In young birds, the Thayer's has milky, dark brown primaries, as apossed to the jet black primaries of the Herring Gull. In flight, the primaries have a two-toned paneling effect, and the Herring gull has a black patch on the wing, which is the primaries.

Adult Thayer's Gull with Herring Gulls (note dark eye, heavey mottling, smallish bill)

First-cycle Thayer's Gull (note wingtip color, and small bill)

Now with the Kumlien's/Iceland comlpex it gets hard. Some Kumlien's Gulls have dark wingtips, which can look like Thayer's Gulls. Then some Kumlien's Gulls can have really white wingtips, which look like Iceland Gulls. This subspecies complex is not fully understood by experts.

More ID tips nest time....

(all photos are by Dan Casey)

The other species is a first-cycle Gaucous Gull. It is the brownish bird (at left) with a pink bill and black tip.

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