156 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



•with grey tinge ; wing-feathers as in C. pygargus but basal part of 

 inner webs of primaries and under side of all wing-feathers whiter ; 

 wing-coverts as in C. pygargus but pale edgings and spots on median 

 and lesser varying but usually larger and more prominent and 

 often extending to outer feathers. 



Nestling.— At first down (a) short but covering bird fairly 

 thickly but scanty on belly, white with bufnsh tinge on sides of 

 head, neck, centre of back and wings, round eye a narrow dark 

 brown ring. In this stage indistinguishable from C. pygargus. 

 Later thickly covered with long down (c) which replaces very 

 short white down (b). Down (c) bumsh-brown on upper-parts 

 but paler on sides of back, under -parts pale buff, whitish on 

 belly. 



Juvenile. — Like adult female and usually not possible to 

 distinguish with certainty, pale edgings of feathers especially 

 on crown and wing-coverts usually more rufous than in adult 

 female and under-parts often more rufous-buff ; pale barring of 

 tail-feathers often paler and whiter especially in males but no 

 reliable difference. Distinguished at once from juvenile C. pygargus 

 by its streaked under-parts. 



First winter. Male and female. — Like juvenile. 



First summer. Male. — Moult occasionally begins March but 

 apparently usually takes place summer (June) and is sometimes 

 not quite complete as late as Nov. and Dec. (i.e. when bird is eighteen 

 months old) but insufficient moulting birds are available. Upper- 

 parts as adult but not so pure grey (more tinged brown) often with 

 some brown-edged feathers on fore-part of crown and on rump ; 

 under-parts as adult but almost always with a few spots or streaks 

 of rufous-brown and sometimes these are well marked and fairly 

 numerous on lower-breast and under tail-coverts. 



Second summer. Male. — After second moult seems indis- 

 tinguishable from adult. 



Measurements and structure. — <J wing 330-355 mm., tail 200-220, 

 tarsus 65-75, bill from cere 15-17 (12 measured). $ wing 360-390. 

 Primaries : 1st between 6th and 7th and sometimes shorter than 

 7th, 3rd and 4th longest, 2nd 20-30 mm. shorter, 5th 15-25 shorter 

 (equal to or longer than 2nd), 6th 65-75 shorter ; 2nd to 5th emar- 

 ginated on outer and 1st to 4th on inner webs. Rest of structure 

 as Marsh-Harrier. 



Soft parts. — Bill black, base bluish ; cere, legs and feet, iris, 

 and eyelid yellow. 



Characters and allied forms. — In C. c. hudsonius (N. America) 

 adult male is spotted on under-parts and female and young usually 

 more rufous on under-parts and edges of feathers of crown and 

 nape. Distinguished from C. pygargus in all plumages by much 

 longer and emarginated 5th primary, and rather longer 4th primary 

 besides other differences. 



