252 CASSELLS BOOK OF BIRDS. 



these birds as inhabit mountain ranges do not migrate ; in Spain they live at an altitude of 3,000 feet 

 above the sea, and even when the snow begins to fall they merely come into the valleys below, and 

 never wander to any great distance from their native haunts. 



The TREE WARBLERS (Phylloscopi) constitute a family whose members are met with 

 throughout the world. With the exception of one group, all are small, slender, delicately-shaped 

 birds, with comparatively long wings, in which the third, fourth, and fifth quills usually exceed the 

 rest in length. The tail is of moderate size, either quite straight or slightly incised at the extremity, 

 and these tarsi are of medium height. The beak is awl-shaped, slender, rather flat at its base, and 

 in some instances somewhat broader than it is high. The plumage is soft, and very uniform in 

 colour ; it is usually of a pale green or brown on the back, and yellowish on the under side. All the 

 species with which we are acquainted principally frequent the summits of trees, but come down occa- 

 sionally to seek their insect food upon the rushes, or in the fields of corn ; they seldom consume 

 berries, unless compelled to do so by hunger. All are active and restless, and display great agility, 

 both among the branches and when running over the surface of the ground ; their powers of flight 

 are also good, their voice always agreeable, and their senses well and sometimes highly developed. 

 Such as inhabit Southern Europe, Asia, and Africa do not migrate, whilst those in milder latitudes 

 leave their native lands late in the autumn, and return to them again in the early spring. These 

 latter species generally breed twice during the summer, and lay from four to seven delicate white 

 or pale rose-red eggs, marked with dark spots. The nests of all are constructed with the utmost care. 



THE FIELD TREE WARBLER, OR WILLOW WREN. 



The Field Tree Warbler, or Willow Wren (Phyllopneuste Trochilus), is a slenderly-formed bird 

 with long wings, in which the third and fourth- quill exceeds the rest in length. The tail is of moderate 

 size, and slightly incised at its extremity ; the beak is delicate, broad at its base, and compressed at 

 its tip. The lax plumage is of an olive green upon the upper parts of the body, and white on the 

 under side, the breast being tinged with greyish yellow ; a yellowish-white stripe passes over the eyes, 

 and the cheek stripes are deep grey ; the quills and tail-feathers are grey, edged with green, and the 

 lower wing-covers light yellow ; the eye is brown ; the beak and legs grey. After the moulting season 

 the under side becomes a pale yellow. This species is four inches and eleven lines long, and seven 

 inches four lines broad ; both wing and tail measure about two inches. The sexes are alike in 

 colour ; the young are greyish green above and yellowish-white on the throat ; the rest of the under 

 side is white, tinted with yellow. 



The Field Tree Warblers inhabit the whole continent of Europe, a large portion of Northern 

 Africa, and some parts of North America. During their migrations they also occasionally visit India 

 and Northern Africa. For the most part, however, such as quit Northern and Central Europe for the 

 winter do not wander farther than its more southern countries. These birds alike frequent highlands 

 and lowlands, and usually pass the summer months in disporting themselves about the leafy summits 

 of lofty trees. In autumn, on the contrary, they come down into the brushwood and beds of reeds 

 or rushes, or, in Southern Europe, alight in the fields of maize in quest of food ; dense forests they 

 appear almost entirely to avoid. The song of this species is pleasing and flute-like ; its chief beauty, 

 however, consists in the delicacy of intonation and rapid swelling and sinking of sound in which the 

 male indulges, as he sits with drooping wing, inflated throat, and raised crest, upon a projecting 

 branch, or flutters rapidly from bough to bough, in order to attract the attention of his intended 

 mate ; at such times the female also utters a faint twittering kind of song. Like the Tree Warblers, 

 these birds are particularly active among the foliage ; they do not creep in the quiet mouse-like manner 



