American Dipper Cinclus mexicanus Scientific name definitions

"[H]is music is that of the streams refined and spiritualized. The deep booming notes of the falls are in it, the trills of the rapids, the gurgling of margin eddies, the low whispering of level reaches, and the sweet tinkle of separate drops oozing from the ends of mosses and falling into tranquil ponds." —John Muir, 1894 (1 Muir, J. (1894). The Mountains of California. The Century Company, New York, NY, USA. Close : 283).

John Muir's “Ouzel” or “Water Thrush” now bears the name American Dipper, a name that describes the most conspicuous habit of most species in the family Cinclidae: a repetitive up-and-down bobbing motion. Admirers of Muir's Ouzel have attributed to it a combination of factual and mythical characters. Muir declared “bird and stream...inseparable,” which is essentially true. Although dippers rarely stray from rushing streams, they do on occasion frequent lakes and seashores. They do not restrict themselves to mountains; some individuals nest along coastal streams from Alaska to California and on desert streams in the Grand Canyon and in Zion National Park.

The American Dipper chooses a nest site, invariably along a stream, that usually provides security from floods and predators. Availability of suitable streams and nest sites and territorial behavior where potential nest sites are close together appear to limit its populations. It eats an exclusively animal diet, composed almost entirely of aquatic insects, invertebrates and, where available, small fish and fish eggs.

This species' distinctive traits include frequent dipping, a blinking white eyelid, and vigorous feeding by jumping or diving into turbulent water even at ambient temperatures well below 0 °C. To persist in this demanding environment, the American Dipper has a low metabolic rate, extra oxygen-carrying capacity in its blood, and a thick coat of feathers. It aggressively defends territories in both summer and winter along streams.

Half a century after Muir's glowing accounts of the American Dipper in the Sierra Nevada, a number of researchers began to study its life history. Hann (2 Hann, H. W. (1950). Nesting behavior of the American Dipper in Colorado. Condor 52:49-62. Close ) studied nesting behavior on the East River in west-central Colorado (near Gothic, Gunnison County). In western Montana (Missoula County), Bakus (3 Bakus, G. J. (1959a). Observations of the life history of the dipper in Montana. Auk 76:190-207. Close , 4 Bakus, G. J. (1959b). Territoriality, movements, and population density of the dipper in Montana. Condor 61:410-425. Close ) studied breeding behavior, and population density; Mitchell (5 Mitchell, P. A. (1968b). The food of the Dipper (Cinclus mexicanus Swainson) on two western Montana streams. M.S. thesis, University of Montana, Missoula, MT, USA. Close ) studied diet; and Sullivan (6 Sullivan, J. O. (1973). Ecology and behavior of the Dipper, adaptations of a passerine to an aquatic environment. Ph.D. dissertation, University of Montana, Missoula, MT, USA. Close ) studied diet, molt, and adaptations to the aquatic environment. Ealey's (7 Ealey, D. M. (1977). Aspects of the ecology and behaviour of a breeding population of Dippers (Cinclus mexicanus: Passeriformes) in southern Alberta. M.S. thesis, University of Alberta, Edmonton, AB, Canada. Close ) study on the Sheep River near Calgary, Alberta, reported on ecology and breeding behavior. In a 3-year study on Boulder Creek in north-central Colorado (Boulder County), Price researched population dynamics (8 Price, F. E. (1975). A study of population dynamics in the Dipper, Cinclus mexicanus. Ph.D. dissertation, University of Colorado, Boulder, CO, USA. Close , 9 Price, F. E., and C. E. Bock (1983) Population ecology of the Dipper (Cinclus mexicanus) in the Front Range of Colorado. Studies in Avian Biology 7. Close ). Working with dippers on the Logan River in northeastern Utah (Cache County), Fite (10 Fite, M. K. (1984). Vocal behavior and interactions among parents and offspring in the American Dipper. M.S. thesis, Utah State University, Logan, UT, USA. Close ) analyzed vocal behavior. Additional studies have addressed the species' physical adaptations (internal and external) to aquatic life (11 Goodge, W. R. (1959). Locomotion and other behavior of the Dipper. Condor 61:4-17. Close , 12 Goodge, W. R. (1960). Adaptations for amphibious vision in the Dipper (Cinclus mexicanus). Journal of Morphology 107:79-91. Close , 13 Murrish, D. E. (1970a). Responses to diving in the Dipper, Cinclus mexicanus. Comparative Biochemistry and Physiology 34:853-858. Close , 14 Murrish, D. E. (1970b). Responses to temperature in the Dipper, Cinclus mexicanus. Comparative Biochemistry and Physiology 34:859-869. Close ).

Recent studies in southern British Columbia have focused on altitudinal migration, life history, fledgling behavior, and toxicology (15 Morrissey, C. A. (2004). Effect of altitudinal migration within a watershed on the reproductive success of American Dippers. Canadian Journal of Zoology 82:800-807. Close , 16 Morrissey, C. A., L. I. Bendell-Young, and J. E. Elliott (2004a). Linking contaminant profiles to the diet and breeding location of American Dippers using stable isotopes. Journal of Applied Ecology 41:502-512. Close , 17 Morrissey, C. A., L. I. Bendell-Young, and J. E. Elliott (2004b). Seasonal trends in population density, distribution, and movement of American Dippers within a watershed of southwestern British Columbia, Canada. Condor 106:815-825. Close , 18 Gillis, E. A., D. J. Green, H. A. Middleton, and C. A. Morrissey (2008). Life history correlates of alternative migratory strategies in American Dippers. Ecology 89:1687-1695. Close , 19 Middleton, H. A., C. A. Morrissey, and D. J. Green (2006). Breeding territory fidelity in a partial migrant, the American Dipper Cinclus mexicanus. Journal of Avian Biology 37:169-178. Close , 20 Middleton, H. A., D. J. Green, and E. A. Krebs (2007). Fledgling begging and parental responsiveness in American Dippers (Cinclus mexicanus). Behaviour 144:485-501. Close , 21 Middleton, H. A., and D. J. Green (2008). Correlates of postfledging survival, the timing of dispersal, and local recruitment in American Dippers. Canadian Journal of Zoology 86:875-881. Close , 22 Whitehorne, I. (2010). Wintering behavior; physiology and site fidelity in a partial migrant, the American Dipper (Cinclus mexicanus). Waterbirds 33:461-470. Close , 23 Green, D. J., I. B. J. Whitehorne, H. A. Middleton, and C. A. Morrissey (2015). Do American Dippers obtain a survival benefit from altitudinal migration? PLOS One 10(4):e0125734. Close , 24 Mackas, R. H., D. J. Green, I. B. J. Whitehorne, E. N. Fairhurst, H. A. Middleton, and C. A. Morrissey (2010). Altitudinal migration in American Dippers (Cinclus mexicanus): Do migrants produce higher quality offspring? Canadian Journal of Zoology 88:369-377. Close ). In southeastern Alaska, Willson and Hocker (25 Willson, M. F., and K. M. Hocker (2008). American Dippers wintering near Juneau, Alaska. Northwestern Naturalist 89:24-32. Close , 26 Willson, M. F., and K. M. Hocker (2008). Natural history of nesting American Dippers (Cinclus mexicanus) in southeastern Alaska. Northwestern Naturalist 89:97-106. Close , 27 Willson, M. F., and K. M. Hocker (2009). Nestling provisioning by American Dippers near Juneau, Alaska. Western Birds 40:29-34. Close , 28 Willson, M. F., G. W. Pendleton, and K. M. Hocker (2009). Distribution, abundance, and survival of nesting American Dippers near Juneau, Alaska. Western Birds 40:191-209. Close ) studied breeding and wintering ecology, parental behavior, and factors limiting distribution and abundance. Lovett (29 Lovett, K. (2017). Monitoring Dippers in the Black Hills. The American Dipper (Cinclus mexicanus) in the Black Hills of South Dakota. South Dakota Department of Game, Fish, and Park Wildlife Division, Pierre, SD, USA. Close ) studied their biology in the Black Hills of South Dakota. As North America's only truly aquatic passerine, the American Dipper combines some characteristics of passerines (melodious song and aggressive territoriality) with some of ducks (feeding, molt, and dense feathering). Most of the information in this account pertains to the subspecies C. m. unicolor, which resides in the United States and Canada; little has been published on the 4 subspecies found in Mexico and Central America (see Systematics: Subspecies).