Bird of the Month - September 2002

Lesser Yellowlegs
Tringa flavipes

by David Fix

An identification question frequently posed among a gathering of birders is, “How do you tell a Lesser Yellowlegs from a Greater Yellowlegs?”  One might hear in reply, “Lesser is half the size of Greater”;  “Lesser’s bill is no more than one head-width long”;  or “Lesser’s call is soft and is only one or two notes.”  Each of these responses is helpful.  A ‘softer’ criterion—yet vivid, and perhaps the most original—is credited to the great north coast birder Alan Barron.  Alan suggests that the bill of Lesser Yellowlegs doesn’t seem like much of a weapon, whereas the bill of Greater Yellowlegs “looks like it could do some real damage.”  Leave it to the experts to make the complex as simple as possible!

Lesser Yellowlegs are fun birds to encounter.  The same certainly can be said for its larger congener--yet the delicacy, elegant figure, and deliberate movements of the Tringa shorebird group all seem to be best exemplified by this species.  They are truly but half the size of Greater Yellowlegs, with body bulk about the same as that of a Killdeer.  Dark above, their feathers are edged or tipped with dots of white;  a variable pattern of fine dark streaking across the breast gives way to white lower breast, belly, and undertail coverts.  ‘Crayon-yellow’ legs and feet are readily noted even in poor light.  The bill is slim and straight, of moderate length, and almost always entirely dark;  the bill of Greater Yellowlegs is usually touched with paler blue-gray at the base, and often (thought not always) looks very slightly uptilted.

Although many shorebirds are found across the Northern Hemisphere, both yellowlegs are ordinarily confined to North and Middle America.  Lesser Yellowlegs breed across the boreal taiga from northwestern Alaska to James Bay.  Much of the migration takes place well to the east of the Pacific Coast, particularly in spring;  most birds appearing in the Redwood Region are seen from early August through September.  Most are juveniles.  A very few linger into early winter at extensive rainpools in the Arcata or Eel River bottoms.  Numbers present vary from year to year.

Although both yellowlegs species commonly mingle at foraging sites, Lesser Yellowlegs are less apt to use the exposed estuarine edge habitats and large tidal sloughs which attract so many Greater Yellowlegs.  They prefer drying freshwater mudflats, grassy rainpools, cobbly river bars, and similar sites offering undisturbed shallow-water edge.  Good places to look for them include the Smith River and Mad River estuaries and Eel River Wildlife Area.  During the peak of their migration, loose flocks of as many as several dozen may scatter throughout expanses of favored habitat, dispersing among Greater Yellowlegs, dowitchers, and other shorebirds.