THE BRITISH NUTHATCH. 223 



emarginated outer webs. Secondaries between 9th and 10th 

 primaries, tips ahnost square. Tail-feathers rounded and not stiff, 

 tail almost square. Bill strong, wedge-shaped, sloped off to fairlj'^ 

 sharp point. A few, fine, short rictal and nasal bristles, and nostrils 

 almost covered with short bristle-like feathers. Claws strong and 

 curved, hind claw decidedly shorter than hind toe. 



Soft parts. — Bill dark slate, base of culmen and basal two-thirds 

 of lower mandible grey ; legs and feet yellowisli-broAMi ; iris dark 

 greyish-brown. 



Characters and allied forms. — Sitta e. ccesia (middle Europe) 

 much resembles *S'. e. britannica but buff of imder-parts is usually 

 of a deeper shade, S. e. hispaniensis (Spain) is much like britannica 

 but smaller and with shorter bill, S. e. caiicasica (Caucasus) has 

 dark under-parts and short bill, S. e. levantina (Asia Minor, Palestine) 

 has paler under-jDarts and much finer bill, *S'. e. jiersica (Persia) is 

 similar bvit joaler above and below, 8. e. europcea (Scandinavia, 

 north Russia) has white under-parts, S. e. homeyeri (east Prussia) 

 has more cream-coloured under-parts, «S'. e. uralensis (east Siberia) 

 is much like >S'. e. europcea but smaller, *S'. e. albifrons (Kamtschatka) 

 has i^aler upiJer-parts and white fore-head ; several other forms 

 inhabit China, while others have been named but are doubtful. Blue- 

 grey upper-parts, chestnut flanks, and wedge-shaped bill are 

 unmistakable specific characters. 



Field-characters. — Differs alike in coloration and form from all 

 other British birds. Unlike Tree-Creeper does not use tail in 

 climbing, and moves upw^ards, downw^ards and sideways indifferentlj*. 

 Presence often made laioAm by loud tapping as it hacks nuts, and 

 b}^ shells of hazel nuts, acorns, beech-mast and yew seeds wedged 

 into crevices of bark. In flight, which is slow and undulating, 

 short tail, stout head and strong pointed bill very apparent. Call- 

 note a clear loud '" twi-twit." In spring this note is repeated by 

 male so rapidh^ as to produce a bubbling cry. Another spring call 

 is a loud clear whistle. 



Breeding-habits. — Usually in a hole in the stem or large branch 

 of a tree at varying heights, occasionally in holes of walls, in Sand- 

 Martins' holes or old Magpies' nests, and twice recorded from the 

 side of a haystack. Nesting-boxes also often occupied. Tlie 

 entrance to the hole is nearly always reduced in size with hard mud. 

 Nest. — Hole usually lined with bark of Scotch fir, less frequently 

 birch bark or clriecl leaves of oak and beech. Eggs. — 5-11, usually 

 5-8 ; white, more or less boldly spotted with red-broA\ai and a few 

 violet shell-marks ; occasionally almost unmarked. Average of 

 100 eggs, 19.2x14.3 mm. Breeding-season. — From the end of 

 April to mid-May, also sometimes late in June. Incubation. — Lasts 

 about 13-14 days, probablj^ by hen only. One brood normally, 

 occasionally two. 



