A spotted sandpiper (Actitis macularius) is a shore bird, but not necessarily a seashore bird. You can find them bobbing along freshwater riverbanks, ponds and lakes as well as at seashores. Despite their name, spotted sandpipers are spotted for only about half the year – during breeding season. At the end of that time in August, spotted sandpipers grow new feathers without spots. Therefore, during the fall and winter, these birds are spotless sandpipers.

In the 1800s, hunters decimated the shorebird population, capturing and killing large flocks of birds. But since they don’t gather in flocks – they are mostly solitary creatures – spotted sandpipers survived this period relatively unscathed.

Spotted sandpipers are not picky about where they live. All they need for a nesting place is a wet habitat with vegetation near a shoreline.

Most sandpipers nest in Canada and the far North, but spotted sandpipers nest in our region as well as in much of the rest of North America. They migrate south for the winter – some only a short distance to the Southern states, but others great distances to the Caribbean or South America. Unlike other shorebirds that migrate in large flocks, spotted sandpipers migrate alone or in small groups.

In many bird species, the males arrive to the breeding ground first to claim and defend a territory. Spotted sandpipers do the opposite: In the spring, females arrive about four days before the males to establish and defend a territory. The females compete to find a male partner, and after a male and female pair up, the two build a nest together. The nests are little more than scrapes in the dirt lined with grass, weeds or stems. After mating, the female lays about four eggs. The male incubates these eggs and raises the young. The female may leave this partner to mate with a second male and lay another clutch of eggs – some of which may have been fertilized by the first male because the female’s reproductive tract stores sperm.

After the eggs hatch in about three weeks, the male attends to the young, but the chicks mature quickly. They walk within hours. They hunt nonmoving prey within two days and stalk moving prey within four. By 11 days, they begin to flap off the ground. They are independent within a month, when they leave the parent to gather with other youngsters who will breed the following summer.

According to an observer in 1925, 

On July 11, in a boggy meadow near the water’s edge, we found a nest of four eggs … On July 25 the eggs had hatched and after a short search we found the young in the grass. They were with the parent, which proved to be the male. The sides of his breast and belly were worn quite bare of feathers, showing that he had done most of, if not all of, the incubating.

Before the males incubate the eggs, they have testosterone concentrations in their blood that is much higher than that of the females. But as they incubate the eggs, these levels drop 25-fold. Female spotted sandpipers may mate with as many as four or five males and lay four or five clutches of eggs. Because of this behavior, spotted sandpipers produce more eggs than other species of sandpiper, about 20 per season. Older, more experienced females have more mates, lay more eggs and have more chicks than do younger females.

Perhaps because of their role reversals when mating, spotted sandpiper plumage coloring is reversed too: Females are spottier than males. They have larger spots that cover a greater percentage of their plumage, an indication of their health and worthiness as a mate. As the birds age, their spots become smaller and more irregularly shaped. After breeding season in fall and winter, the breast is white, not spotted.

Spotted sandpipers are unusual in another way, too. In flight, the bird flutters its stiff wings like flaps, often just barely above the water. Its flight looks more like a fluttering motion than a streamlined flight.

Spotted sandpipers eat almost anything they can catch (except for toad tadpoles), including flies, beetles, caterpillars, spiders, snails, worms and small fish. They are easy to recognize as they forage because of their bobbing and teetering. They may peck at the ground to snatch bugs or hop to catch flying insects.

If a predator approaches a nest, the adult sandpiper crawls along the ground, flapping its wings as if injured, spreading its tail and shrieking. In this way, the “injured” bird can lead the predator away from the eggs or chicks in the nest. When the predator gets far enough away from the nest, the adult bird will fly away.

These 7-inch birds are often referred to as “spotties” or “teeter-bobs.” The second name comes from their propensity to bob their rear end up and down like a teeter-totter. 

Near a stream, pond or beach, keep your eyes peeled for this little teetering bird.

Reader photo

Jean Bodiford sends this photo of a Baltimore oriole in Ohio from Sept. 26.

Have you taken photos of our urban wild things? Send your images to Cambridge Day, and we may use them as part of a future feature. Include the photographer’s name, date and the general location where the photo was taken as well as any other relevant information.

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Jeanine Farley is an educational writer who has lived in the Boston area for more than 30 years. She enjoys taking photos of our urban wild things.