The American Dipper is gray and plump, an aquatic songbird that inhabits western rivers and streams from Alaska to Central America. This is a bird that can’t stand still. It is usually noticed by its continual bobbing while standing on a rock at the edge of or in a stream.
The dipper is a permanent resident within its range. It favors clear, fast-moving, clear mountain waters but also can show up in lowland riparian areas. It is present on streams with good water quality and sufficient food. The dipper in the accompanying photos was on Yost Park’s Shell Creek in November 2012. There are no other known records of this species in Edmonds.
Aquatic insects make up most of the diet of the American Dipper. They include larvae of caddisflies, mayflies, beetles, bugs, and mosquitoes, as well as the adults of these insects. It will eat some worms and snails and tiny fish (less than three inches in length). It forages by walking with its head submerged and by diving and swimming underwater. It will also walk on the bottom, probing the streambed’s stones and rocks. This is a short video of a young bird foraging in a stream: https://www.youtube.com/watch?v=pvounfNeuuk.
When courting, either adult may strut and sing in front of the other, with its wings drooping and bill pointed upward. Natural nest sites include a ledge on a mossy rock wall just above a stream, among the roots of a dirt bank or behind a waterfall. The dipper looks for a place where the nest will remain wet from flying spray. Nests are also sited on the undersides of small bridges that now span many mountain streams.
The nest is probably built by the female. It is domed and about a foot in diameter, built with mosses, twigs, and rootlets. A large entrance is low on one side of the nest. The female incubates her 4-5 eggs for about two weeks. Both adults feed the nestlings. The young birds leave the nest about three weeks after hatching. They are able to swim and dive almost immediately. The American Dipper is usually a solitary bird, so after the chicks fledge, the parents often divide their brood and territory and then part ways.
The American Dipper is mostly non-migratory. It will stay through winter, even in the far north, where fast moving water remains unfrozen. Some will move to lower elevations and slightly southward in winter. The oldest American Dipper of record was more than 8 years of age when it was recaptured and re-released during a banding operation in South Dakota. A group of dippers is collectively known as a ladle. There are five species of dippers, distributed locally across Eurasia and the Americas.
The American Dipper is a species of low concern for conservation purposes. It appears to be relatively stable and the breeding population is estimated at 190,000. Breeding has been enhanced by bridges, which offer additional nesting locations. The dipper is an indicator species of water quality. Certain logging, mining, and agricultural practices can degrade water quality and reduce the availability of aquatic insect prey. Dippers are also vulnerable when waters are contaminated with organic pollutants such as PCBs and heavy metals.
You can listen to an American Dipper’s song here: https://www.xeno-canto.org/460527.
— By Carol Riddell
Carol Riddell manages the bird education displays, on behalf of Pilchuck Audubon Society and Edmonds Parks & Recreation, at the Olympic Beach Visitor Station.