Greater Yellowlegs

Our two species of yellowlegs are one of New Hampshire’s frequent identification challenges. Although easily distinguished from other shorebirds by their bright yellow legs in all plumages, these common migrants often require a closer look to separate if not seen together (when the size differences are usually obvious). The most important feature is the bill, which in the Greater Yellowlegs is noticeably heavier and longer than the head from front to back. In contrast, the finer bill of the Lesser Yellowlegs would barely extend beyond the back of the head if folded back against the face. Calls are also diagnostic, with Greater giving a three-note “tu tu tu” and the Lesser only two. Note that both species sometimes give more or fewer notes, so some familiarity with tone may also be required.

Yellowlegs nest on the ground in the boreal forests of Canada and Alaska, usually near bogs or in other areas with interspersed wetlands. The Lesser nests farther north than the Greater and can also be found where forest starts shifting into tundra. Both species have a more complex breeding song that they give from the ground, a conspicuous perch, or during flight displays. Like most shorebirds, they lay four eggs, which in the case of both yellowlegs are incubated for a little over three weeks. The young are precocial, meaning they can move about and feed themselves shortly after hatching.

We only see yellowlegs in New Hampshire during migration, when they are most common in coastal salt marshes with much lower numbers inland in shallow wetlands and flooded fields. They spend the winter from the southern United States to southern South America, usually near coastlines or areas with extensive wetlands. It is during this period that yellowlegs have historically faced their greatest threats. Habitat loss is an issue for all shorebirds, but since yellowlegs are dispersed migrants it likely affects them less than other shorebirds. Instead, hunting is thought to have had a significant impact on populations during the market hunting era of the late 1800s, with populations rebounding as it was banned. Hunting of these species, particularly the Lesser Yellowlegs, is still a problem in parts of the Caribbean and South America. The practice is largely not regulated, resulting in thousands of birds being taken each fall. New conservation initiatives are hoping to introduce more regulation in shorebird hunting in these regions with the goal of helping stabilize current population declines.