These long-legged birds look similar but there are subtle differences to look for. Here's how to distinguish a greater vs lesser yellowlegs.
How to Identify a Greater Yellowlegs
Look for greater yellowlegs in marshy habitats such as pond edges and wet meadows. Identifiable by their yellow colored legs (hence the name) and brown barring against white plumage, they boast a long beak that they use to catch food in shallow water. In nonbreeding plumage, the greater yellowlegs features slightly less brown coloration.
These birds travel through the United States during migration, en route to their breeding grounds in Canada and Alaska. They spend winters along coastlines in the southern U.S., in Mexico and South America.
How to Identify a Lesser Yellowlegs
Lesser yellowlegs typically appear in marsh-like habitats — many of the same places frequented by its larger relative. Recognizable by their thin, straight bill and yellow legs, birders can watch them probe in mud or in water to find snails, flies, beetles or other prey.
As is the case with the greater yellowlegs, these birds make their way through the United States as they migrate to and from Canada. They spend winters along southern American coastlines, and in Mexico and South America.
Learn how to identify a solitary sandpiper.
Greater Yellowlegs vs Lesser Yellowlegs
It can be difficult to tell the greater and lesser yellowlegs apart by size difference if the birds aren’t spotted together, but a few key things can help in identification.
One of the best ways to tell greater and lesser apart is by their bill shape, but there is some variation in both species. The bill of the greater yellowlegs is not only longer but also thicker, and the base of the bill often looks gray, not black. The lesser yellowlegs generally features a shorter, thinner bill than the greater. Brown barring is more prominent on the flanks of the greater than the lesser, especially in spring and summer.
Another way to tell these birds apart is by ear. Greater yellowlegs give a loud, ringing tew-tew-tew call, commonly repeated in phrases of three or four; lesser yellowlegs give a harsher, shorter tu.
Range and Migration
“While walking along the Allegheny River last spring, I spotted a bird I have never seen in this area before (above). I believe it is the shorebird yellowlegs. Does it belong in our area, or was it just visiting?” asks Birds & Blooms reader Dori Montgomery of Rimersburg, Pennsylvania.
Birding experts Kenn and Kimberly Kaufman say, “Yes, you’re right on both counts: Your bird is a greater yellowlegs, and it’s a shorebird, a member of the sandpiper family. Greater yellowlegs don’t live in Pennsylvania at most times of the year; they spend the summer mostly in Canada and Alaska, and in winter they can be found from the Southern U.S. to South America. During spring and fall, these impressive migrants may show up at the water’s edge almost anywhere, including the margins of lakes, ponds and rivers. So the one you found along the Allegheny was on its normal migratory route, but it’s always exciting to spot one of these birds on its travels.”
Conservation and Habitat Loss
The Cornell Lab of Ornithology has identified both the greater and lesser yellowlegs as Orange Alert Tipping Point species, meaning these birds lost more than 50% of their respective populations in the past 50 years. In addition, they have seen accelerating decline throughout the past decade. The greatest threat to them is a loss of their winter habitat.
Sources
- Cornell Lab of Ornithology, “Greater Yellowlegs: Identification,” “Lesser Yellowlegs: Identification“
