1<)2 
atj.en's naturalist’s library. 
Falco gyrfalco {nec L.), Mac« Brit. B. iii. p. 284 (I84o^ 
Hierofako candicans, Sharpe, Cat. B. Brit. Mus, p. 4ii'(i874> • 
B. O. U. List Br. B. p. loi (1S83). 
(Plate L.) 
Adult Male. — Snow-white, with scarcely a spot. 2 "he head 
and under-parts snmvy-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; culmen, I'l; wine, la'c ■ 
tail, 7-8; tarsus, 2-3. w 4 5 , 
Adult Female.— Similar to the male, hut 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 lon>^i- 
tudinal streaks on the under surface; lores and sides efface 
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- 
ogists^as to the changes of plumage through which the Green- 
land (jyr- 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 aee of 
the bird. ^ ° 
First of all, therefore, it is necessary to state that a Green- 
niscd date fioiu wliich Uritish oriiithofo^ists Sturt. 
Dr. Stejneger, however, 
suys (.^uk, if. p. 185) that Euglmh uurh;V;,“;Ta;tinrfrom';h\^72r^^^^ 
call It Pako tslandus, Fabriciu.s, Faun. Groenl. p. 
of Linnreus, will have to 
58 (1780, ex Bruun.) ” As, however, the name of islandus is iiiSeadin^’ 
and has been referred to the Iceland Falcon by most European authors,!! 
lb far better to keep to the clearly-defined name of candicans, about which 
there can be no doubt, and hence no confusion. 
