20 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



Nestling. — Down, buffish-grey ; distribution, humeral, spinal,, 

 femoral and ulnar ; mouth, inside deep orange, no spots (A. G. 

 Leigh, Brit. B., iii, p. 154.) 



Juvenile. — Crown brownish-black, slightly glossy ; nape and 

 sides of neck greyish-brown ; ear-coverts with silvery tinge ; 

 mantle, back, and rump black-brown ; under-parts paler brown 

 with slight greyish tinge ; tail and wings as in adult but rather 

 less glossy, lesser and median coverts brown-black with scarcely 

 any gloss. 



First winter and summer. — ^Like adult, but tail and wing- 

 feathers, greater wing-coverts, and often some median and lesser 

 coverts browner and less glossy, becoming in summer often quite 

 brown and almost devoid of gloss. The juvenile body-plumage 

 and majority (often all) lesser and median and usually innermost 

 greater coverts are moulted in autumn, but not rest of coverts 

 and wing- and tail-feathers. 



Measurements and structure. — (^ wing 228-246 mm., tail 

 124-140, tarsus 42-47, bill from nostril 23-26 (12 measured). 

 $ wing 225-243. Primaries : 1st equal to or shorter than 10th 

 or between 9th and 10th, 3rd and 4th usually equal and longest,, 

 2nd and 5th 12-20 mm. shorter, 6th 30-40 shorter ; 2nd to 5th 

 emarginated outer webs. Secondaries between 9th and 10th 

 primaries, square tipped, slightly notched. Tail nearly square, 

 very slightly rounded. Numerous rictal and nasal bristles, latter 

 completely covering nostrils. 



Characters and allied forms. — C. m. monedula (Scandinavia) 

 has slightly greyer under-parts and small white or creamy- 

 white patch at base of side of neck, C. m. collaris (eastern 

 Europe, western Asia) is very like typical form, but sides of neck 

 are paler and white patch is rather larger, C. m. cirtensis 

 (Algeria) is as grey on under-parts as C. m. monedula, but has 

 no white patch on sides of neck. The European forms intergrade 

 and series must be compared. Silvery-grey sides of neck and 

 nape unmistakable specific character. 



Field-characters. — Smaller size, dapper appearance, and a 

 certain pert alertness in actions, distinguish Jackdaw at all ages 

 from more sedate Rook and Crows, Silver-grey nape and ear- 

 coverts of old bird afford additional distinction. In flight differs 

 from Rook, with which it frequently consorts, by quicker wing- 

 beats and its notes, " cae " and " jack " ; alarm-note uttered at 

 nest is " caw." 



Breeding-habits. — Usually breeds in hole, whether of tree,, 

 building, rock, or rabbit-burrow, but sometimes builds large open 

 nest of sticks with deep cup, occasionally roofed, in trees. Shows 

 tendency to sociability, several pairs often breeding close together. 

 Nest. — ^Varies according to site, enormous quantities of sticks used 

 in some cases, but absent from small holes, which are merely 



