The American Dipper

By Archives •  Updated: 07/20/22 •  7 min read

The American Dipper (Cinclus mexicanus) is a small waterbird that lives in North America. They are found in the Pacific Northwest, Rocky Mountains, and the Great Lakes region.

There are five dipper species worldwide – all dippers spend their entire lifecycle in and along rivers and streams. Dippers dive into cold, fast-flowing water in search of aquatic prey

American Dippers have a black cap, brownish-black back, and white underparts. They are also known as “water ouzels” or “water dippers” because they spend most of their time swimming underwater in streams and rivers searching for food. Cinclus mexicanus feeds mainly on aquatic insects like mayflies and caddisflies, but they also eat small fish and tadpoles.

Both male and female dippers are singers. The song is a long, fluty, wren-like arrangement of notes that can extend from 10 seconds to several minutes in length. Their call is a repeated ‘jhe’ and they often give a rattling call in flight. The female makes a soft ‘whump’ noise in the presence of nestlings.

Feeding And Foraging

American Dipper (Cinclus mexicanus)

American Dipper (Cinclus mexicanus). Credit: Ron Knight, CC-BY

Dippers eat the aquatic larvae and emerged adults of many aquatic invertebrates including caddisflies, stoneflies and mayflies as well as the eggs, alevin and fry of salmon. Dippers reach their aquatic prey by diving into the water and swimming by beating their wings.

They dive for an average of 5 seconds often in raging rivers suited to adventure rafting. Unfortunately, its penchant for diving underwater in search of food can now and then make it the prey of large freshwater fish such as bull or Dolly Varden trout.

Their anatomy and physiology are a good match to their aquatic lifestyle.

They have extra layers of feathers to keep them warm and an enlarged oil gland that is applied to the feathers to keep them dry, and a third eyelid, or nictitating membrane that helps them to see while underwater.

Dippers make use of their grasping feet to hold onto underwater features to help them stay submerged and move around in the powerful water. Dippers also catch flying insects out of the air and pick prey off the surfaces of rocks, stream banks, and the water surface.

American Dipper Breeding

Dippers mate monogamously. They form pairs at the end of winter often with the same mate and on the nesting territory occupied the previous year (Middleton et al. 2006).

Birds that breed on the lower elevation river begin nest-building or renovations as early as late-February. Birds that breed at higher elevations begin breeding about 2 weeks later.

The breeding season extends from late February until early July. Dippers begin breeding earlier than most songbirds likely to avoid nest loss to high spring floods fed by melting snow off nearby mountains.

Where Does The American Dipper Nest?

Dippers locate their nests on surfaces that overhang flowing water. They have been found on a variety of structures including mid-stream boulders, logs overhanging the water, river banks, cliff edges, under bridges and culverts, and other man-made structures.

The nest is built from moss plucked from the banks of the river and is shaped like a soccer ball with a lining of grass and leaves. The opening overlooks the water below. The nest is constructed in about a week by both parents.

Once complete, the female lays a clutch of 4 or 5 eggs and incubates for 16-18 days. Young hatch within a day of each other and are brooded for up to 10 days. They are provisioned by both parents on a diet of aquatic insects and fish.

The chicks depart the nest about 24-26 days after hatching – a relatively long nestling period for a songbird. They continue to be fed by both parents and depart from the parent’s territory anywhere between 6-21 days after leaving the nest (Middleton 2006).

Pairs often initiate a second brood, especially if the first one is depredated or destroyed by spring floods. The male does not incubate or brood the young. While females are incubating or brooding young in the nest, the male will often stand sentry on a favorite rock or log in the territory looking out for intruders. This is a good sign that there is a nest nearby.

Are American Dippers Aggressive?

Dippers defend an exclusive breeding territory against other dippers from about March to July. The territorial aggressiveness relaxes during the winter months when large numbers of dippers share popular river stretches.

Territorial defense is performed by both sexes. Intruding dippers often fly silently over territory at a high altitude to elude detection. Intruders are quickly approached by territorial holders.

One or both birds will stretch into a long, high posture with their bills pointed straight up in the air. The contest ends when one bird submits by crouching low on the ground where it is jumped and pecked.

Territorial holders will pursue intruders in a long, vocal chase and mid-air squabble. Disputes often end with one bird forcing the other under the water.

How to Support American Dipper Populations & Habitats in Your Area

American dipper populations are not at risk. However, the dipper’s strictly aquatic lifestyle makes them an ideal indicator of the health of rivers. Studies on Eurasian dippers (Cinclus cinclus) show they are sensitive to changes in stream water quality associated with human activities including stream acidity (Ormerod et al 1991) and toxins and silt in the water. They need a wetland full of snails to thrive.

In order to support the American dipper’s populations and habitats in your area, you can:

– Contribute to the National Wildlife Federation Action Fund https://nwfactionfund.org/

– Volunteer with your local Audubon Chapter or other conservation organization

– Plant native plants in your yard

Cinclus mexicanus, the American dipper, known also as the water ouzel was iconic naturalist John Muir‘s favorite bird. He even dedicated an entire chapter in his book ‘The Mountains of California’ to the Ouzel writing

“He is the mountain streams’ own darling, the humming-bird of blooming waters, loving rocky ripple-slopes and sheets of foam as a bee loves flowers, as a lark loves sunshine and meadows. Among all the mountain birds, none has cheered me so much in my lonely wanderings, —none so unfailingly. For both in winter and summer he sings, sweetly, cheerily, independent alike of sunshine and of love, requiring no other inspiration than the stream on which he dwells. While water sings, so must he, in heat or cold, calm or storm, ever attuning his voice in sure accord; low in the drought of summer and the drought of winter, but never silent.”

Sources:

Elliott, Charles L.; Peck, Steve (December 1980). Dipper swallowed by trout (PDF). Wilson Bulletin. 92 (4): 524.

Kingery, H. E. 1996. American Dipper (Cinclus mexicanus). In: Poole, A. and Gill, F. (eds) The Birds of North America, No. 229. The Academy of Natural Sciences, Philadelphia, PA., and The American Ornithologists’ Union, Washington, D. C.

Middleton, H. A., Morrissey, C. A. and D. J. Green 2006. Breeding territory fidelity in a partial migrant, the American dipper Cinclus mexicanus. Journal of Avian Biology 37: 169-178.

Middleton, H. A. 2006. Post-fledging behaviour and dispersal of American dippers. M.Sc. thesis, Simon Fraser University, Burnaby, BC

Morrissey, C. A. 2002. The ecological and toxicological significance of altitudinal migration by the American dipper (Cinclus mexicanus). PhD. thesis, Simon Fraser University, Burnaby, BC

Muir, John (1894) The Mountains of California. New York, The Century Co.

Ormerod, S. J., O’Halloran, J., Gribbin, D. D. and S. J. Tyler 1991. The ecology of dippers (Cinclus cinclus (L)) in relation to stream acidity in upland Wales: breeding performance, calcium physiology and nestling growth. Journal of Applied Ecology 28: 419-433.

Tyler, S. J. and S. J. Ormerod 1994. The Dippers. T & A. D. Poyser, London, UK

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