The American Dipper is North America's only truly aquatic songbird. It is a chunky bird of western streams, catching all its food by walking and swimming on swiftly flowing streams' bottoms.
American Dippers are chunky, round-bodied birds with a short tail and long legs. Adults are grey all over with white eyelids. Their thin bills turn dark during breeding season. Immature dippers are similar to adults, but have faint pale barring on their underside and lighter bill.
American Dippers are about the size of robins. Adults measure 5.5-7.9 inches (14-20 centimeters) in length and weigh 1.5-2.4 ounces (43-67 grams).
American Dippers live almost solely on rushing, unpolluted waters of the West. Dippers forage in streams with rocky bottoms, and they use streams with overhanging banks for cover and nesting locations. American Dippers don't migrate, though they may move to larger, unfrozen rivers in winter or follow insects in spring or summer.
American Dippers feed on small aquatic invertabrates. To find prey, American Dippers rapidly duck their heads in and out of water. After prey is found, they can wade, swim, and dive either from the water or from the air, and can move rocks on the stream-bottom to catch food.
American Dippers build nests on cliff ledges, behind waterfalls, on boulders, and on dirt banks or under bridges, but always nest close to a fast flowing stream. Females will choose an appropriate ledge or crevice for nesting that is 6-20 feet above deep water so that the nest will not be in danger of predators or flooding.
Males and females may work together to build the nest, round like a ball, often in freezing temperatures. Nest materials are dipped into water before being weaved into two layers: an outer shell that is 8-10 inches in diameter, made of moss, and an inner chamber with a woven cup that is 2-3 inches in diameter, made of grass, leaves, and bark. Once the nest is finished, the mossy shell absorbs moisture and the coarse grass keeps the inside dry.
American Dippers will have 1 to 2 broods with 4 to 5 eggs in each. The eggs are white with a length of 0.9-1.1 inches (2.3-2.8 centimeters) and a width of 0.7-0.8 inches (1.7-1.9 centimeters). The incubation period for American Dippers are 14-17 days and nesting period is 24-26 days. After the eggs hatch, the hatchlings are helpless with sparse down.
American Dippers are mainly monogamous, meaning they only have one mate in a period of time. They are mainly solitary birds, the parents dividing their brood and their territory and part ways after the chicks' fledging.
Though American Dipper populations are difficult to count, their numbers appear to be relatively stable, though they've experienced a small decline recently.
- A low metabolic rate, extra oxygen-carrying capacity in its blood, and a thick coat of feathers helps the American Dipper survive in cold waters during the winter.
- During molting in summer, the American Dipper is temporarily flightless.
- The oldest American Dipper was over 8 years old when it was recaptured and released during a banding operation in South Dakota.
- Other names for these dippers are Mirlo Acuático Norteamericano (in Spanish) and Cincle d'Amérique (in French).