90 



DIPPER. 



fine series in the British Museum, it ajjpears to me that C. melafio- 

 gaster is merely a dark form which inhabits the northern countries of 

 Europe, and the higher mountain regions of the south. Even in 

 Derbyshire, Dippers from the Peak district at 1,500 feet are darker 

 than birds from 1,000 feet lower down; and examples from the 

 upper portions of the narrow valleys of the Pyrenees above Luz, 

 and from the lofty Cantabrian Mountains, in North-western Spain, 

 are undistinguishable from Scandinavian specimens. Lower down, 

 and also on the river Genii near Granada, the Dippers have a broad 

 chestnut band, and belong to a race intermediate between our 

 British form and another, paler on the back, called by separatists 

 C. albicoUis ; the latter inhabiting the Alps, the Carpathians, Italy 

 and Greece. From the Caucasus and Asia Minor eastward to 

 Tibet, intergraduating races lead to the browner-backed C. cash- 

 miriensis ; while in the Atlas Mountains is found yet another form, 

 distinguished by Canon Tristram as C. minor. Under these cir- 

 cumstances I have considered it advisable to treat both the forms 

 of Dipper which occur in our islands under one heading, while 

 admitting that the extremes of each race are recognizable. 



The nest is a large oval ball of moss, grass, or leaves, with an 

 entrance low down in the side ; lined with dry grass and dead leaves. 

 It is placed in a recess under a bridge, in the wall of a mill dam, 

 in a bank, or on a ledge of rock, often behind a cascade of water ; 

 sometimes in the boughs of trees overhanging a river. The eggs, 

 4-6, are of a dull white : average measurements i in. by '75 in. 

 Fully fledged young have been found on March 21st ; and not only 

 are two and even three broods reared in the season, but a second 

 clutch of eggs is often deposited in the same nest. The song, 

 begun in autumn, may frequently be heard throughout the winter, 

 and always early in spring. The food consists of soft-shelled 

 molluscs, spiders, aquatic beetles and other insects, with their larvse ; 

 many of which are known to be destructive to the spawn of trout 

 and salmon. In the pursuit of its prey, the bird employs both legs 

 and wings, using the latter like oars ; while the young are able to 

 swim freely as soon as they leave the nest. 



Adult : head and nape umber-brown ; upper parts mottled with 

 dark grey and brown ; tail and wing-feathers dark brown ; chin, 

 throat and upper breast white ; lower breast dark chestnut-brown, 

 passing into black on the flanks and lower belly ; bill brownish- 

 black ; -legs and feet brown. Length 6"5 in. ; wing 375 in. The 

 sexes are alike in plumage. The young are greyish-brown above, 

 and have no chestnut-brown on the under parts. 



