1 92 ALLEN'S NATURALIST'S LIBRARY. 



Falco gyrfalco (nee L.), Macg. Brit. B. iii. p. 284 (1840). 

 Hierofako candicans, Sharpe, Cat. B. Brit. Mus~ p. 411 (1874); 

 B. O. U. List Br. B. p. 101 (1883). 



(Plate L.) 



Adult Male. Snow-white, with scarcely a spot. The head 

 and under-parts snowy-white, entirely unspotted, or perhaps 

 with a few black stripes on the nape ; on the back a few drops 

 of black, some inclined to be longitudinal in shape, others 

 pear-shaped or oval in form; quills white, with remains of 

 spots, or notches, on the outer web, and a few fragments of 

 bars on the inner webs, which are for the greater part white; 

 tail pure white, with white shafts ; cere and orbits yellow; bill 

 pale yellow, with a bluish tip; feet pale yellow; iris dark 

 brown. Total length, 23 inches; oilmen, i'i; wing, 14*5; 

 tail, 7'8; tarsus, 2-3. 



Adult Female. Similar to the male, but seldom so completely 

 white. Total length, 23 inches; culmen, 1*5; wing, 16*2; tail, 

 9-5 ; tarsus, 2-35. 



Young Birds. White, but never with a pure white head or 

 under-parts, being streaked with brown, the pattern some- 

 what irregular on the upper surface, and confined to longi- 

 tudinal streaks on the under surface ; lores and sides of face 

 streaked with brown ; the tail white, the centre feathers with 

 brown cross-bands, more or less broken, and forming only spots 

 or mottlings on the other feathers. 



I am at issue with some of our most distinguished ornitho- 

 logists as to the changes of plumage through which the Green- 

 land Gyr-Falcon passes in arriving at maturity. Many of them 

 believe that the differences exhibited by a series of specimens 

 are caused by there being a light and dark race, while I con- 

 sider that every difference can be accounted for by the age of 

 the bird. 



First of all, therefore, it is necessary to state that a Green- 



nised date from which British ornithologists start. Dr. Stejneger, however, 

 says (Auk, ii. p. 185) that " English authors, starting from the I2th edition 

 of Linnaeus, will have to call it Falco islandus, Fabricius, Faun. Groenl. p. 

 58 (1780, ex Briinn.)." As, however, the name otislandus is misleading, 

 and has been referred to the Iceland Falcon by most European authors, it 

 is far better to keep to the clearly-defined name of candicans, about which 

 there can be no doubt, and hence no confusion. 



