The American dipper (Cinclus mexicanus), also known as a water ouzel, is a semiaquatic bird species native from North America. On average, it measures in length, has a wingspan of , and weighs .

Taxonomy

The American dipper was described by English zoologist William Swainson in 1827 based on a specimen that had been collected in Mexico by English naturalist William Bullock. Swainson placed the new species with the dippers in the genus Cinclus and coined the current binomial name Cinclus mexicanus. The type locality is Temascaltepec de González in Mexico.

The five subspecies are:

  • C. m. mexicanus Swainson, 1827 – north and central Mexico
  • C. m. anthonyi Griscom, 1930 – southeast Mexico, southwest Guatemala, east Honduras and northwest Nicaragua
  • C. m. ardesiacus Salvin, 1867 – Costa Rica and west Panama
  • C. m. dickermani Phillips, AR, 1966 – south Mexico
  • C. m. unicolor Bonaparte, 1827 – Alaska, west Canada and west USA

Distribution and habitat

The American dipper inhabits the mountainous regions of North America from Alaska to Panama. It is usually a permanent resident, moving slightly south or to lower elevations if necessary to find food or unfrozen water. The presence of this indicator species shows good water quality; it has vanished from some locations due to pollution or increased silt load in streams.

Behaviour and ecology

thumb|leftThe American dipper defends a linear territory along streams. In most of its habits, it closely resembles its European counterpart, the white-throated dipper (Cinclus cinclus), which is also sometimes known as a water ouzel.

Breeding

The American dipper's nest is a globe-shaped structure with a side entrance, close to water, on a rock ledge, river bank, behind a waterfall, or under a bridge. The normal clutch is two to four white eggs, incubated solely by the female, which hatch after about 15–17 days, with another 20–25 days to fledging. The male helps to feed the young. The maximum recorded age from ring-recovery data of an American dipper is 8 years and 1 month for a bird ringed and recovered in South Dakota.

Feeding

It feeds on aquatic insects and their larvae, including dragonfly nymphs, small crayfish, and caddisfly larvae. It may also take tiny fish or tadpoles.

Predators

Dippers may occasionally be preyed on by predatory fish such as by brook, bull or Dolly Varden trout.

History

The American dipper, previously known as the waternouzel, was the favorite bird of famous naturalist John Muir. He dedicated an entire chapter in his book The Mountains of California to the ouzel, stating, "He is the mountain streams' own darling, the hummingbird 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."

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File:Cinclus mexicanus - Nason Creek, Washington, USA -juvenile-8.jpg|Juvenile in Nason Creek, Washington, USA

File:CinclusArdesiacusWolf.jpg|Subspecies C. m. ardesiacus, lithograph by Joseph Wolf, 1867

File:Cinclus mexicanus Zion.webm|Foraging in a stream

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References

Further reading

  • Erlich et al. The Birder's Handbook
  • Stiles and Skutch, A guide to the birds of Costa Rica
  • American Dipper - Cinclus mexicanus - USGS Patuxent Bird Identification InfoCenter
  • American Dipper Species Account - Cornell Lab of Ornithology
  • for United States
  • The Dipper - Plain, yes, but not so ordinary
  • American Dipper photo gallery VIREO
  • Short radio episode The Water-Ouzel, from The Mountains of California, by John Muir 1894. California Legacy Project.
  • The American Dipper and Biodiversity Conservation Alliance