TREE-CREEPERWREN 23 



except the related subspecies, the Scandinavian rock-pipit 

 (A. spin, littoralis), which is a rare visitor to Great Britain by 

 the almost complete absence of white on the outer tail- 

 feathers. Sexes alike. Upper-parts olive-brown with darker 

 striations. Under-parts dull white mostly striated dull brown. 

 After the autumn moult the upper-parts have a greenish and 

 the under-parts a yellowish hue. 



Nest. Usually in a crevice of a rocky cliff. Material : dry 

 grass, bents, lined with finer grass and hair. 



Eggs. Usually 4-5. Greyish to brownish, speckled thickly 

 with shades of brown. Av. size, -83 x '62 in. Laying begins 

 April-May. Two broods. 



(6) Family : Certhiidce Tree-creepers 



37- Tree-creeper [Certhia familiaris britannica Ridgway ; 

 C. familiaris (Linnaeus)]. More or less stationary 

 in most woodland districts. 



Bird. Length 5*5 in. Usually seen creeping up 

 and round the trunks of trees. Distin- 

 guished by the slender curved beak, long 

 pointed tail-feathers, and silky white 

 under-parts. The upper-parts are 

 mostly brown with paler streaks. 

 Rump rust colour. Wings brown 

 with buffi sh bar. 



Nest. Place : usually behind loose 

 bark on the trunk of a tree, also be- 

 hind ivy stems or in suitable crevices 

 in walls, outbuildings, &c. Material : 

 twigs, moss, roots, grasses, &c., lined 

 with feathers, wool, down, &c. 



Eggs. Usually 5-6. White, marked generally at the large 

 end with reddish spots. Av. size, '61 x *47 in. Laying begins 

 April-May. 



(7) Family: Troglodytidce Wrens 



38. Wren [Troglodyte? troglodytes troglodytes (Linnaeus); 

 Troglodytes parvulus K. L. Koch]. Resident and common. 

 Two other forms, the St. Kilda wren (T. t. hirtensis Dixon) 

 and the Shetland wren (T. t. zetlandicus Hartert) are con- 

 fined to the islands after which they are named. 



Bird. Length 3J in. The species is easily recognised by 

 its small body, short tail, and characteristic shape. (See 

 Fig. 22.) The common form has the upper-parts gener- 



