By Ana Weidenfeld
Yap! Yelp! Yellow! Now is the time to spot the Greater Yellowlegs (Tringa melanoleuca) in the Bay Area. Though this is one of the most widespread shorebirds, the Greater Yellowlegs only breeds in central Canada and southern Alaska. In late June, this graceful bird moves south to spend the winter months in fresh and saltwater wetlands in the United States and Central and South America. In the springtime, they begin to return north. The Greater Yellowlegs are more solitary than most other shorebirds but they can form small flocks during migration.
Aside from the obvious long yellow legs, you can tell that you’re looking at the Greater Yellowlegs by its upright stance. It is a medium-sized bird with a long neck and a bill that is slightly upturned and rounded. These features set it apart from the Lesser Yellowlegs (Tringa flavipes), which has a sharp, pointed and dark colored beak and also emits a different cry. The Greater Yellowlegs has a white rump and tail, with darker wing feathers. Its wingspan, for both sexes, measures around 60 centimeters.
Another telling sign that the Greater Yellowlegs is nearby is its sharp and intense call of three or four notes. The bird calls out a piercing squawk at any sign of trouble, explaining its nicknames of tattler and yelper.
The Greater Yellowlegs enjoys feeding on a variety of invertebrates and small fish, which are ample in Bay Area wetlands this time of year. This bird is also known to eat small frogs, crustaceans and occasionally berries and seeds. These yelpers feed by wading through shallow waters, bobbing their heads up and down and sweeping their bills side to side in order to feel and catch prey.
The Greater Yellowlegs, like most shorebirds, builds its nest in a concealed area on the ground by making a small depression in the soil and filling it with leaves, mosses and twigs. Greater Yellowlegs birds are thought to pair for life and raise one brood a season, with both parents helping to incubate the four eggs for about three weeks. New hatchlings are remarkable in their ability to leave the nest within a few hours!
An apparent mud-lover, the Greater Yellowlegs chooses to breed in boggy land that is brimming with mosquitoes, making it one of the most ubiquitous shorebirds without much known about its breeding biology. As frustrating as this is for scientists, the low density and hidden nests of this bird also work to shield the population from possible threats. Furthermore, their ability to change migration times and wintering habitat will no doubt help the population in the face of increased wetland habitat destruction in the future.
Keep an eye and ear pealed for this yellow-legged dandy!