Western Willet is a chunky, tall, long-legged, long-necked shorebird that is gray brown in any season; see Fig. 5.

The drab appearance of Western Willet vanishes as soon as the bird opens its wings to display the brightly contrasting black-and-white wings. The tail is white with gray barring toward the tip; see Fig. 3, Fig. 12, Fig. 19.

The long legs are gray or blue gray; see Fig. 2, Fig. 5.

The dark, nearly all-black bill is tapered, straight, and long. The bill base is often tinted bluish. Sometimes the bill is slightly up curved; see Fig 1, Fig. 5, Fig. 7. The female’s bill may be surprisingly long; see Fig. 13.

In most plumages, the dark bill contrasts sharply with the pale plumage.

Winter (basic) plumage is a pale gray buff. Each back (mantle) feather has a crisp, dark center line (feather shaft). The neck and upper breast are lightly speckled with gray; see Fig 1, Fig. 2.

In spring, Western Willet’s back (mantle) plumage begins to acquire the brown barring of spring (alternate) plumage. Some birds retain a smattering of worn and bleached winter (basic) feathers well into April; see Fig. 4.

As spring progresses, Western Willet acquires darker plumage; see Fig. 5, Fig. 6.

Many individuals do not molt into full alternate plumage in their first summer after hatch-year. By retaining a mix of worn winter (basic) and summer (alternate) feathers, they end up looking tattered and unkempt; see Fig. 7.

Spring (alternate) and summer (alternate) are the same plumage for Western Willet, but as the seasons progress, alternate plumage for older individuals begins to look darker because the feather margins become worn; see Fig. 8.

The newly hatched downy chick is precocial; it can run about and feed itself soon after emerging from the egg; see Fig. 9.

Both parents spend a short time tending to chicks by brooding and guarding against predators, females for about two weeks after hatching, males for an additional two weeks.

Western Willet chicks replace natal down with juvenile plumage. Juvenile wing covert feathers show pale broad margins, usually with a submarginal dark line, which parallels the feather margin; see Fig 10.

As summer progresses into fall, juvenile back (mantle) feather margins become worn and frayed. Fresh winter (basic) feather begin to grow in; see Fig. 11, Fig. 13.

Western Willet (WEWI) and Eastern Willet (EAWI) are considered subspecies of willet. They differ sufficiently from each other in plumage, size and migration patterns to justify being treated in separate “species” accounts in this guide. For comparison, see Fig. 14.

Note the following:

• In nearly all plumages, Western is paler and grayer and Eastern is darker and browner.
• Western Willet is, on average, larger than Eastern.
• In both subspecies, females are larger. The variation in size among different populations of Western Willets is much greater.
• There is a size overlap between the subspecies; a large female Eastern may be larger than a small male Western.
• Western Willet is, on average, longer-billed than Eastern. Western Willet’s bill often shows bluish at the base; Eastern Willet’s bill is often pinkish at the base.
• Western Willet has a longer, more tapered, pointy bill, sometimes with a slight upcurve. Eastern Willet’s bill is thick throughout and blunt.
• Western Willet’s pale head and body contrast with its nearly all-dark bill, especially in winter.
• Western Willet is longer-legged than Eastern.
• Western Willets breed along the shores of inland lakes or ponds or in freshwater wetlands. Eastern Willets are rarely found far from marine coasts.
• Western Willets winter along the coasts of southern North America, Central and South America and the Caribbean region. Eastern Willets winter south of the United States border.

Western Willet (WEWI) and Greater Yellowlegs (GRYE) are long-legged, tall shorebirds that roost and feed in similar habitats, often together. For comparison, see Fig. 15.

Note the following:

• Western Willet is larger, chunkier and less elegant than Greater Yellowlegs.
• The Willet’s bill is long, thick, tubular and blunt. Greater Yellowlegs has a tapered, pointy bill. Either species may have a slightly upturned bill.
• In flight, Western Willet has flashing black-and-white wings from above and below. Yellowlegs’ wings are medium grey above and pale grey with barring from below.
• Willet’s legs are dull gray or blue gray. Yellowlegs have bright yellow legs.
• In spring and summer (alternate) plumage, Western Willet has a barred back (mantle) and barred tertials (long feathers lying over the primaries). Greater Yellowlegs in breeding plumage has a spotted and checkered back (mantle) and tertials with pale zigzag margins.
• Greater Yellowlegs emits tyou-tyou-tyou calls when alarmed, occasionally multiple times. It also yodels. Willet’s song and territorial call is pill-will-willet, sometimes repeated over and over.

Western Willet (WEWI) and Lesser Yellowlegs (LEYE) are long-legged, tall shorebirds that roost and feed in similar habitats, often together. For comparison, see Fig. 16.

Note the following:

• Western Willet is much larger than Lesser Yellowlegs.
• The Willet’s bill is long, thick, tubular and blunt. Lesser Yellowlegs has a tapered, pointy bill.
• In flight, Eastern Willet has flashing black-and-white wings from above and below. Yellowlegs’ wings are medium grey above and pale grey with barring from below.
• Willet legs are dull gray or blue-gray. Yellowlegs have bright yellow legs.
• In spring and summer (alternate) plumage, Western Willet has a barred back (mantle) and barred tertials (long feathers lying over the primaries). Lesser Yellowlegs in breeding plumage has a spotted and checkered back (mantle) and tertials with pale zigzag margins.
• Lesser Yellowlegs emits tu-tu calls when alarmed, occasionally multiple times. It also yodels. Willet’s song and territorial call, pill-will-willet, is often repeated over and over.

Western Willet (WEWI) and Whimbrel (WHIM) are similar in size and have similar gray-brown plumage. For comparison, see Fig. 17.

Note the following:

• Whimbrel may be slightly larger with a longer, downturned bill.
• In flight, Western Willet has flashing black-and-white wings from above and below. Whimbrel is brown above and pale below with no notable wing markings.
• Western Willet’s head has an indistinct brown cap and a pale line from the bill to above the eye (supercilium). Whimbrel’s head is distinctly marked with multiple brown and pale lines through the eyes and over the crown.

Western Willet (WEWI) is smaller than Marbled Godwit (MAGO). The birds are easily separated due to the shape of the bill and overall coloration; see Fig. 18, Fig. 19.

Note the following:

• Western Willet’s bill is long, tubular and somewhat blunt, with a mostly dark outer portion and bluish-tinged base. Marbled Godwit’s bill is very long, tapered and upturned. The outer half of the bill is dark, and the inner half is pinkish.
• On the ground, Western Willet is plain gray-brown or barred brown. Marbled Godwit coloration ranges from pale to rich orange-rufous with brown bars and spots.
• Western Willet in flight has boldly marked black-and-white wings. Marbled Godwit in flight is an even-toned orange-rufous bird.
• Western Willet’s wings are rounded compared to the wings of Marbled Godwit.

Western Willet (WEWI) and Black-belied Plover (BBPL) are chunky shorebirds that appear gray in most (not all) seasons. For comparison, see Fig. 20.

Note the following:

• Western Willet is a much larger bird than Black-bellied Plover.
• Western Willet has a characteristic long, slim sandpiper pill. Black-bellied Plover’s bill is relatively short and stubby, typical of plovers.
• The Western Willet juvenile’s back (mantle) plumage is pale gray brown with wide whitish margins and submarginal dark lines (dark lines paralleling the margins). The Black-bellied Plover juvenile is checkered dark gray and pale on the back (mantle).
• Western Willet in winter (basic) plumage is plain pale gray brown on the back (mantle) with very narrow whitish margins on the mantle feathers. Black-bellied Plover’s winter (basic) mantle feathers are gray with pale zigzag margins.
• In flight, Western Willet’s wings are brightly contrasting black-and-white from above and below. Black-bellied Plover’s wings from above are grayish with a bold white stripe; from below, the wings are white with black axillars (wingpits).

Juvenile Red Knot (REKN) can look like a miniature version of juvenile Western Willet (WEWI); see Fig. 21.

Note the following:

• Western Willet is about twice the size of Red Knot.
• Western Willet’s bill is much longer than Red Knot’s bill.
• Western Willet and Red Knot juvenile back (mantle) feathers have pale margins and submarginal dark lines (dark lines paralleling the margins).
• Western Willet juvenile has a spattering of pale gray on the upper breast and neck. Red Knot juvenile has fine grey vermiculation or spotting on the breast, which often extend to the flanks.
• In flight, Western Willet’s wings are brightly contrasting black-and-white. Red Knot’s wings are grayish from above with a very narrow whitish wing stripe. Red Knot’s tail is all gray, whereas Western Willet’s tail is whitish with a finely gray-barred tip.