68 THE YELLOW WAGTAIL 



as the Pied Wagtail. It is slate-grey above, the wing coverts, quill 

 feathers and six central feathers of the tail being black, the throat 

 is black, and the under-surface bright yellow. The nest is built 

 early in spring in a bank, much like that of the Pied Wagtail, and 

 usually contains five eggs, or sometimes seven may be found, of a 

 creamy-white colour, speckled with light brown blotches. Fre- 

 quenting brooks and other watercourses, also ponds and marshes it 

 destroys numbers of fresh-water molluscs, such as Limnaea trun- 

 catula and L. pereger, well-known hosts of the liver-fluke (Distoma 

 hepaticd), subsisting entirely upon insects. The grey wagtails 

 migrate southward in the autumn, and though some may remain 

 in Devon and other southern counties of England, they generally 

 leave the British shores in the autumn. 



The YELLOW WAGTAIL (Motacilla Rayi) arrives in England in 

 March or April and is generally distributed over England and southern 

 districts of Scotland, but in the northern parts of that country and 

 in Ireland the Yellow Wagtail is rarely seen. It is mainly of a yellow 

 colour ; upper parts olive or greenish-yellow, and lower parts of a 

 canary or light yellow. The female is not so bright in colour as 

 the male. The bill and feet are black. It is about 6J in. in 

 length. On arrival in this country the Yellow Wagtails frequent 

 marshes and grass-land, but soon pair and go to cultivated land, 

 hunting for insects, even following the plough, and devouring milli- 

 pedes, wireworms, and other insects as they are disturbed or turned 

 up. Breeding begins early. The nest, usually made on the ground 

 in grass or tufts or on a bank, is composed of dried bents and roots, 

 with dried grass and wool or hair, or even fine roots, for a lining. 

 Four to six eggs are laid, varying in colour from pinkish-brown to 

 a darker brown. Two broods are sometimes produced in a season. 

 After young are hatched, the birds move off to meadows, pastures 

 and marshes, where they follow cattle and sheep for the insects 

 around them. Found near watercourses, ponds, and marshy 

 places they devour fresh-water molluscs, amongst them snail- 

 hosts of the liver-fluke. The Yellow Wagtails leave Britain in 

 September and October. 



The WHITE WAGTAIL (Motacilla alba), regarded as a mere variety 

 of the Pied Wagtail, is only an occasional visitant to this country. 

 The BLUE-HEADED WAGTAIL (Motacilla ftava) is even more rare in 

 Great Britain. 



The TREE PIPIT or TITLARK (Anthus trivialis or arbor eus), Fig. 

 45, belongs to the Dentirostral Perchers and is included in the sub- 

 family of the Motacillinae or Wagtails, which it closely resembles 

 in its habits of running swiftly on the ground. The bill is of moder- 

 ate length and slender, with the tip of the upper mandible notched 

 and curved. The wings are long and pointed, the tertiary feathers 

 being of great length. The tail is also elongated. It has a shorter 

 curved hinder claw than the Meadow Pipit, though even this bears 



