One of the most ubiquitous shorebirds in North America, the Greater Yellowlegs restricts itself as a breeder to swampy muskeg habitats of central Canada and southern Alaska. During the nonbreeding season, it inhabits fresh and saline wetlands across the Americas. More solitary than most shorebirds, it is rarely seen in large numbers, although small flocks form during migration. Its bright yellow legs, upright stance, and distinctive call make it easy to distinguish from other North American shorebirds, except its congener the Lesser Yellowlegs (Tringa flavipes).
Vernacular names for this species include telltale, tattler, and yelper, all of which vividly describe its piercing alarm calls. Considered a fine game bird earlier in the twentieth century, many a yellowlegs was shot “by an angry gunner as a reward for its exasperating loquacity” ( Bent 1927 : 321). Such hunting probably contributed to population declines during this period, but numbers appear to have recovered since then. As with many aspects of the species' biology, however, quantitative data for these trends are lacking.
Known to eat a variety of invertebrates and to feed regularly on small fish, the Greater Yellowlegs winters in the southern United States and throughout Central and South America. It migrates in a broad front across North America and is often among the first shorebirds to arrive in spring. Its fall migration is prolonged, with the first birds returning in late June and the last lingering into early winter.
Although the Greater Yellowlegs is common and widespread, its low densities and tendency to breed in inhospitable, mosquito-ridden muskegs make it one of the least-studied shorebirds on the continent. Like most shorebirds, it nests on the ground, where its cryptic coloration and tenacity make nests difficult to find. Consequently, its breeding biology remains poorly known; most current knowledge is based on limited observations or inferred from detailed studies of the closely related Common Greenshank (T. nebularia) in Europe ( Nethersole-Thompson and Nethersole-Thompson 1979 ). The accounts of William Rowan ( Rowan 1929 , Rowan 1930 , Rowan 1943 ) and Thomas Randall (in Bannerman 1961 ) from central Canada, as well as a recently initiated study by Lee Tibbitts in southern Alaska, provide much of our knowledge of the Greater Yellowlegs on its breeding grounds.
More is known about the nonbreeding biology of this species, although few studies have focused exclusively on the Greater Yellowlegs. The most detailed studies of this shorebird during the nonbreeding season have been conducted by Raymond McNeil and colleagues, largely in Venezuela. Among other things, this work has provided important information on foraging ecology (e.g., Robert et al. 1989 , Robert et al. 1989 ), migration (e.g., McNeil and Cadieux 1972a ), and the role of parasites in causing birds to summer away from breeding grounds (McNeil et al. McNeil et al. 1996 , McNeil et al. 1996 ).