LIST OF ILLUSTRATIONS. 



Alpine Swift (Apus m. melba), head 



Swift (A. a. apus), primaries of juvenile . . 



Needle -tailed Swift (Chcetura c. caudacuta), tail 



Nightjar (Caprimulgus e. europceus), head 



Egyptian Nightjar (C. as. cegyptius) , head 



Algerian Red-necked Nightjar (C. r. desertorum), head 



Bee-Eater (Merops apiaster), head 



Roller (Coracias g. garrulus), outer tail-feathers 



Kingfisher (Alcedo a. ispida), head 



Green Woodpecker (Picus v. virescens), head of juvenile 



British Great Spotted Woodpecker (Dryobates m. anglicus) and Northern 

 Great Spotted Woodpecker (D. m. major), bills 



British Great Spotted Woodpecker (D. m. anglicus), dwarf taihfeather 



Great Spotted Woodpecker and Lesser Spotted Woodpecker (D. m. 

 comminutus), showing differences in pattern of upper-parts 



Wryneck (Jynx t. torquilla), head 



Wryneck, primaries of adult and juvenile 



Cuckoo (Cuculus c. canorus), head of juvenile 



Great Spotted Cuckoo (Clamator glandarius), head 



American Yellow-billed Cuckoo (Coccyzus a. americanus) and American 

 Black-billed Cuckoo (C. erythropthalmus), outer tail-feathers 



Tengmalm's Owl (Mgolius f. funereus), Little Owl (Athene n. mira), 

 and Scops-Owl (Otus s. scops), feet 



Plate I.^Heads of 1, European Hawk-Owl (Surnia u. ulula). 2, 

 White-breasted Barn-Owl (Tyto a. alba). 3, Snowy Owl (Nyctea 

 nyctea). 4, Short-eared Owl (Asiof.flammeus). 4a, Flank-feather. 

 5, Long-eared Owl (Asio o. otus). 5a, Flank-feather. 6, Little 

 Owl (Athene n. mira). 7, Eagle-Owl (Bubo b. bubo). 8, Tengmalm's 

 Owl (Mgolius f. funereus). 9a, Juvenile, 9 , Adult Tawny Owl 

 (Strix a. sylvatica). 10, Scops-Owl (Otus s. scops) . . . . facing 



Plate 2.- — 1, Tawny Owl: juvenile feather with filament of nestling 

 down. 2, Barn-Owl : first winter feather with 2nd and 1st nestling 

 down. Portions of outer webs of 1st primaries of : 3, Short - 

 eared Owl, 4, Long-eared Owl. 5, Nestling in down, 6, Juvenile 

 Long-eared Owl . . . . . . . . . . . . facing 



Barn-Owl (Tyto a. alba), middle toe and claw 



Gyr-Falcon (Falco r. rusticolus), head 



Greenland Falcon (F. r. candicans), head 



Peregrine Falcon (F. p. peregrinus), head of juvenile 



Hobby (F. s. sub'buteo), head of juvenile 



Merlin (F. c. cesalon), head of juvenile 



Plate 3. — 1, Feathers of nestling Kestrel showing down (A) at tips. 

 2, Down (C) of same, showing down (B) at tips. 3, Under -down 

 of feathered Kestrel. 4, Merlin a few days old, and 5, about a 

 fortnight old . . . . . . . . . . . . . . facing 



ICestrel (F. t. tinnunculus) and Lesser Kestrel (F. n. namnanni), wing- 

 formulas 



Golden Eagle (Aquila c. chrysaetus) and Sea-Eagle (Haliceetus albiciUa), 

 bills and middle toes 



PAGE 



2 

 5 

 8 

 11 

 15' 

 17 

 20 

 27 

 31 

 53 



38 

 40 



43 

 46 

 47 

 52 

 56 



61 



71 



92 

 97 

 101 

 105 

 107 

 113 

 116 



120 

 124 

 131 



