by Bob Shanman
Which two North American counties have the most documented species of birds in North America? Hint: Both are in California, and their total counts are different by one bird. The answer is at the end of the article.
Walking along the beach near the surf zone you see many different sized birds feeding in the sand. Most are in the sandpiper family of birds (feeding in the sand with a piping motion of the bill). Worldwide, there are 97 species of sandpipers. Thirty-nine of these species have been seen in Los Angeles County at least once. Twenty-five occur regularly if not annually, some in exceptionally large numbers, including the two described below. These birds winter all along the South Bay coast on rocky shorelines, surf zones, quiet mudflats in and near King Harbor, and on the rocky jetties in the Harbor. We find them from Los Angeles Harbor to the Ballona Wetlands.
The sandpipers we see from August through May are in their dull winter, or basic plumage. Many are small, and not unlike the gulls, they can look similar. But the small sandpipers occupy specific feeding niches, which helps with identifying them.
Let’s start with the little bird who runs down to the water as the waves recede, rapidly probing the sand with a stout, black beak for small sand crabs and other food. As the next wave comes in, the bird runs up the slope, like they are trying to keep from getting their wet feet. Then boom, a dog comes running by and the bird takes off. It may be alone or with five to 10 others of its kind. These are Sanderlings. They are the cutest of the sandpipers we see on the beach. They are seven to eight inches long and weigh one to four ounces. In winter they are white with mottled light gray wings and back, and black wingtips. They have long, pointed wings, excellent for flying long distances quickly. Amazingly, their wingspan is about 14 inches. In their breeding plumage, their upper chest, head, and back are brown mottled with black with snow white undersides. Quite a striking difference. Sanderlings are unique among sandpipers in that they do not have a hallux, or hind toe, which makes it easier for them to run along the sand!
Despite their small size, Sanderlings are long distance migrants. Their breeding range is circumpolar in the high arctic in Canada, Greenland, and Siberia. They arrive on the breeding grounds in late April. A typical pair will have four eggs that hatch in about 30 days. Young will fledge in another 17 days. The young are off the nest and feeding on their own with a parent nearby within hours of hatching. One or both parents will stay with the young until they fledge. As with many arctic-breeding birds, nesting and hatching are timed to hopefully coincide with arctic insect hatching, which is their primary food source.
Once fall migration begins, Sanderlings disperse throughout the world to coastal areas, some moving as far south as the tip of Chile. They can cover some 77 degrees of latitude, moving mainly along coastal migration routes. Think about that: an eight-inch-long bird weighing about four ounces traveling 5,300 miles, only to turn around and go the other way four to five months later. The longevity record is 14 years and 10 months. If we figure 14 round trips for that bird, the total is about 148,000 miles.
The second bird this month also feeds primarily in the surf zone and is also a sandpiper. But it’s not nearly as cute and is much larger. These birds are plain grayish brown all year, only getting some dark streaking on the chest and black feather edgings on the wings going into the breeding season. They too, move with the ebb and flow of the waves until one catches them by surprise. Suddenly they fly, screaming “pill will willet” and show a flashy black-and-white wing pattern. Meet the Willet. So dull, but then so striking. They often occur in large groups. It is not unusual to find several hundred on the rocky banks of Ballona Creek near Marina del Rey in the winter.
Willets are found on both coasts with two distinct breeding populations. The focus in this article is on the western population, referred to as the Western Willet. This group winters primarily from Humboldt Bay in northern California south to as far away as coastal Chile. Some individuals find their way to the Atlantic and Gulf coasts. Going north, they are casual visitors to Oregon, Washington, and British Columbia. Some even make it to Alaska.
The Western Willet is 13 to 16 inches long and weighs from about seven to 12 ounces. The wingspan is about 27 inches. When they fly, you can see the long, pointed wing shape of a fast, long-distance migrant. In its winter plumage (as we see it most often), its back and wings are pale grayish brown, and the underside is pale brown bordering on white. It may show a little white around the dark eye, and the beak and legs are dark. Interestingly, they have a small amount of webbing between their toes. As willets molt into their breeding plumage, the wing feathers will show black edges making the wings look darker, and some horizontal barring will show on the chest. March is the time to see them transitioning to this plumage before they head off to the interior. The oldest known Willet lived to about 12 years and three months.
As with some other large sandpipers, Western Willets breed inland on lakes, marshes, and grasslands. The breeding range extends from northeastern California and Nevada going northeastward into Manitoba, Canada. They begin arriving on nest sites in mid- to late April. Like most shorebirds, they are ground nesters. Willet colonies go through a mate selection ritual that may last several weeks. Once paired off, the female typically lays four eggs in a grass-lined scrape, which she will incubate during the day. The male sits on the eggs at night. The eggs hatch in about four weeks, and the young are off the nest and feeding themselves in two days. Parents stay with the young until fledging about four weeks after hatching (the female leaves at about two weeks). Fall migration (August through October) takes them back to the west coast. Willets may not breed until they are two to three years old, so it is not unusual to see them all summer on South Bay beaches and rocky shorelines.
So, there you have it. Two common sandpipers that are seen regularly on the local beaches, both probing in the sand at the waterline for the rich foods they feed on. One is so cute; the other strikingly flashy when it flies.
Ah, yes. Back to the quiz. The two counties are Los Angeles and San Diego. Los Angeles has 542 documented species and San Diego has 541. By a quirk of politics, San Clemente Island is in Los Angeles County, so the rarities seen there are included in the Los Angeles total.
Next month is all about terns (neither left or right). In the meantime, enjoy the birds and be safe on the coast. Pen
