442 CERTHIID^. 



black tipped with asliy, which gradually changes to white and 

 increases in extent towards the outer tail-feathers ; chin and 

 throat pni-e white ; remainder of lower plumage ashy slate, the 

 under tail-coverts fringed with white ; axillaries crimson. 



Colours of soft parts. Iris dark brown ; bill, legs and feet black- 

 Measurements. Total length about 170 to 180 mm. ; wing 94 

 to 102 mm.; tail about 50 to 54 mm.; tarsus 25 to 27 mm.; 

 culmen 27 to 32 mm. 



In summer the crown of the head becomes grey and the chin 

 and throat black. The female has generally rather less black on 

 the throat than the male. 



The young resemble the adult in winter plumage but there is 

 less crimson on the wing and all the quills have each two rufous 

 spots on the inner web. These spots gradually disappear, except 

 on the first four large primaries, where they eventually turn white. 



Distribution. The mountains of Europe and Asia, breeding 

 throughout the Himalayas at suitable elevations and descending 

 lower in winter, occasionally venturing actually into the plains in 

 exceptionally cold weather. 



Nidification. Tlie Wall-Creeper breeds throughout the Hima- 

 layas between 14,000 and 16,000 feet, in some cases as low as 

 12,000 feet. Whitehead found it breeding in Cliitral and the 

 Kurram Valley and Whymper actually found its nest with young in 

 June in the Lidar Valley in Garhwal. The young were old enough 

 to leave the nest on the 27th of that mouth. In Tibet it breeds in 

 some numbers just above the Gyantse Plains at little over 12,000 feet, 

 laying in the early part of May onwards. Owing to the inacces- 

 sible places in which it builds and to its habit of placing its nest 

 deep down in crevices of unbreakable rock, few nests have been 

 taken in India, though the Tibetans know well many places in 

 which it breeds. The nest is just a pad of moss and grass, more 

 or less mixed and lined with wool, fur or hair, wedged 

 into the bottom of some deep but narrow crevice of the rock-face 

 of a precipitous cliff. The eggs number four to six and are 

 pure, but rather dull, white with a few specks and spots of black 

 or deep red-brown at the larger end. In shape they are broad 

 ovals, decidedly compressed and pointed at the smaller end. The 

 n)easurements of 20 eggs, including 15 mentioned by Hartert, 

 are: — average 21-3 x 14-9 mm.; maxima 22-7 X 157 and 20-8 x 

 160 mm., Diinima 20*0xl4'0 mm. 



Habits. This beautiful little bird haunts the face of precipitous 

 cliffs aud great rocks, scuttling about over their surface just as the 

 Tree-Creepers do over the trunks of great trees. Unlike the 

 Tree-Creepers, however, they have a habit of constantly fluttering 

 about the holes and crevices as they search for their insect food 

 and, when so employed, they are singularly like large and beautiful 

 butterflies. This curious habit has earned them the name of 



