American Dipper

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American Dipper

Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Cinclidae
Genus:	Cinclus
Species:	C. mexicanus

Binomial name

Cinclus mexicanus
Swainson, 1827

The American Dipper (Cinclus mexicanus), also known as a Water Ouzel, is a stocky dark grey bird with a head sometimes tinged with brown, and white feathers on the eyelids cause the eyes to flash white as the bird blinks. It is 16.5 cm long and weighs on average 46 g. It has long legs, and bobs its whole body up and down during pauses as it feeds on the bottom of fast-moving, rocky streams. It inhabits the mountainous regions of Central America and western North America from Panama to Alaska.

This species, like other dippers, is equipped with an extra eyelid called a "nictitating membrane" that allows it to see underwater, and scales that close its nostrils when submerged. Dippers also produce more oil than most birds, which may help keep them warmer when seeking food underwater.

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

The song consists of high whistles or trills peee peee pijur pijur repeated a few times. Both sexes of this bird sing year round. It defends a linear territory along streams.

Its habit of diving and walking along the bottom of streams in search of food sometimes makes it the occasional prey of large salmon or other anadromous fish.

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.

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.

[edit] References

BirdLife International (2004). Cinclus mexicanus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 12 May 2006. Database entry includes justification for why this species is of least concern
Erlich et al The Birder's Handbook
Stiles and Skutch, A guide to the birds of Costa Rica ISBN 0-8014-9600-4