180 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



feathered are very thickly covered with down which appears to 

 be same as down (c) in Peregrine (see p. 108) ; very little down (a) 

 is to be seen and this seems short and cream-coloured. In these 

 older nestlings upper-parts are dark smoke-brown with a line of 

 white down back from nape to tail and bases of rest of down 

 white, under -parts whitish, but tips of down smoke-brown, giving 

 a slightly speckled appearance. 



Juvenile. — Like adults but crown and nape usually more 

 streaked, all feathers of upper-parts and wing-coverts as well as 

 primaries, secondaries and tail with broad white or huffish-white 

 tips, brown pectoral band narrower than in adults and more mixed 

 with white, tail-feathers with much longer white tips than in adult, 

 central pair often with more or less obsolete pale brown bars and 

 rest with much more well-defined bars on outer webs, these being 

 on outer feathers often whitish-brown, bars on inner webs well defined. 



First winter and summer. — -White tips of feathers of juvenile 

 plumage soon become much worn down and not obvious. Juvenile 

 body-plumage sometimes commences to moult in October but 

 usually later, moult seems very gradual as in adults, and wings and 

 tail do not moult until spring and moult is usually not complete 

 until autumn (i.e. when bird is about one and a half years old). 

 When this moult is complete bird so far as I can see is like adult. 



Measurements and structure. — $ wing 450-495 (one 510) mm., 

 tail 185-220, tarsus 58-69, bill from cere 30-35 (12 measured). 

 $ wing 470-510. Primaries : 1st equal to or 5-10 mm. longer or 

 shorter than 5th, 3rd longest, 2nd 5-10 mm. shorter or sometimes 

 as long, 4th 10-15 shorter, 5th 55-70 shorter ; 2nd to 5th emar- 

 ginated outer webs (emarginated portions very slightly serrated), 

 lst-4th abruptly emarginated and attenuated on inner webs. 

 Outer secondaries shorter than 10th primary, inner ones becoming 

 longer and longest about equal 7th primary, tips rather sharply 

 rounded. Tail square, 12 feathers, tips rounded. Tarsus feathered 

 in front a little below tarsal joint. Scales on back of tarsus and 

 on sides of and under toes very rough and forming short spines. 

 Claws long, curved, rather slender and very sharp, that of middle 

 toe flattened on inner side. Bill rather broad at base, upper 

 mandible curved and tapering to sharp point projecting much 

 beyond lower mandible which is short, shallow and with rounded 

 tip. Nostrils oblong and bare. Short bristles round eyelids. 



Soft parts. — Bill black, base bluish ; cere pale greyish-blue ; 

 legs and feet greenish-white ; iris yellow. 



Characters and allied forms. — P. h. cristatus (Australia, etc.) 

 has whiter head ; P. h. carolinensis (N. and S. America) has very 

 little brown on breast and is smaller. White on head and under- 

 pays and general structure easily distinguish Osprey. 

 Field-characters. — Unmistakable, looking in distance deep 

 brown with white under side and head, and has very long wings. 

 Often seen flying over lakes (also rivers and sea), sometimes circling, 



