Gulls are a Diverse and Fascinating Group of Birds
Popularly known as sea gulls, these birds actually occur at the seashore and far inland as well. Each winter thousands of gulls gather along the Tennessee River. Three species form the majority of the flocks. Although these birds dominate the flocks, careful examination of these massive groups regularly turns up uncommon and vagrant species. As more and more people study gulls, we are learning that the only true way to identify these birds is by detailed observations of feathers patterns and molt. Because identification rules are still being written, this has become an extreme form of birding that can be incredibly challenging.
Free Food for All
Gulls occur in great abundance at each of the three main dams in Northern Alabama. The main attraction here is the variety of food that is continually churned through the dam's turbines. This provides a smorgasbord for hungry gulls and encourages them to sit around waiting for an easy meal. This regular habit makes it easy to compare their complicated plumage patterns.
Ring-billed Gulls are the most abundant gull in the Tennessee River Valley. Adults are easily identified by their white head, ringed bill, yellow legs and pale eyes. Juveniles can be trickier, but their heavy
pink bill with a black tip and pale gray on the back could distinguish them from potential western vagrants.
Herring Gull are the most common large gull found along the river. However, it is also on of the most difficult gulls to identify since it can have a myriad of different plumages. Recent studies have shown that what was once considered a single species could be several species. The identification of these different species is still being studied and is one of the greatest identification challenge, in North America.
Laughing Gull are uncommon but regular visitors to the Tennessee Valley from the Gulf coast. Adult laughing gulls during nesting season are marked with a black head, deep red bill, and slate colored back. Younger birds have brownish plumage and a black bill. Unlike some of the male migratory gulls, Laughing Gulls can appear at any time of the year.
The elegant Bonaparte's Gull is a small gull which is easily identified in winter the dark spot behind its eye combined with pale leading edge to the upper and lower wing. In breeding plumage, adult birds how a black cap and dark bill, differentiating the Bonaparte Gull from other larger black headed gulls.
· Franklin's Gull Search for this Great Plains vagrant in fall when this medium sized black-headed gull is likely to pass through in small numbers. The pattern of black and white in the wing tip usually gives adult Franklin's Gulls away when seen in flight.
· Glaucous Gull - This arctic species is not recorded annually, but when it is present its large size, stark white plumage, and big pink and black bill help you pick it out in a crowd.
· Lesser Black-backed Gull - Adult birds of this annually visiting species can often be singled out by their dark mantle and yellow legs. Juvenile birds are more of a challenge but can be told by subtle differences in head shaped and wing pattern.
· Great Black-backed Gull - This is North American's largest gull. Its hugh size, thick bill, and pink legs distinguish it from the Lesser Black-backed Gull and others.