The American dipper ( Cinclus mexicanus), also known as a water ouzel, is a semiaquatic bird species native to western North America and parts of Central America.
Description
The American dipper is a stocky grey
bird with a head sometimes tinged with brown, and white
on the eyelids that cause the eyes to flash white as the bird blinks.
On average, it measures in length, has a wingspan of , and weighs .
Taxonomy
The American dipper was described by the English zoologist
William Swainson in 1827 based on a specimen that had been collected in Mexico by the 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.
There are five subspecies:
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C. m. mexicanus William Swainson, 1827 – north and central Mexico
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C. m. anthonyi Ludlow Griscom, 1930 – southeast Mexico, southwest Guatemala, east Honduras and northwest Nicaragua
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C. m. ardesiacus Osbert Salvin, 1867 – Costa Rica and west Panama
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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
Central America and western North America from Panama to Alaska. It is usually a
bird migration resident bird, 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
American dipper defends a linear territory along streams. In most of its habits, it closely resembles its
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 2–4 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
Bird ringing 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
and their larvae, including
dragonfly nymphs, small crayfish, and
caddisfly larvae. It may also take tiny fish or
.
Predators
Dippers may occasionally be preyed on by predatory fish such as by
brook trout,
bull trout or Dolly Varden trout.
History
The American dipper, previously known as the water-ouzel, 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 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."
==Gallery==
-
Erlich et al. The Birder's Handbook
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Stiles and Skutch, A guide to the birds of Costa Rica
External links
