BROWN AND WHITE JER-FALCONS. 17 



FALCO CASDICANS. 

 WHITE JER-FALCON. 



Accipiter falco freti hudsonis, Jiriss. Oni. i. p. OoO (1760). 



Accipiter gyrfalco, JBriss. Orn. i. pi. xxx. tig. 2 (1700). 



Falco rusticolus, Faber, Faun. Groenl. p. 55 (1780). 



Falco islaudu.-, Faber, Faun. Grotnl p. 58 (1780) ; Lath, Gen. Syn. Stippl. i. p. 282 



(1787). 



Falco islandus /3. albas, Gmd. Syst. Xaf. i. p. 271 (1788, ex Eriinn.). 

 Falco candicans, Gmel. Si/*t. Xat. i. p. 27-5 (1788) ; et auctonun plurimomm 



ScMeyel, Strickland, Rtinhardt. Xeicton, Gray, Sharpe, &c. 

 Falco islaudicus (Urifs.), apud Lath. Ind. Orn. i. p. 32 (1790). 

 Falco groenlandicus, Tin-ton's Gtu. %->Y. Xat. i. p. 147 (1806). 

 Hierofalco caudicans (Gmel.), Cue. Regne An. \. p. 312 (1817). 

 Falco gyrfalco. Linn, apud Pall. Zo^gr. Hosfo-As. i. p. 324 (1826). 

 Falco islandicus caudicao*, Holb. Zeitechr. Ges. Xat. iii. p. 426 (1854). 

 Falco (Hierofalco) gyrfalco (Linn.), var. candicans (Gmel.), Ridyic. X. Amer. Birds, 



iii. p. Ill (1*74). 



Au anonymous reviewer, iii an able article on this subject (Ibis, 1862, 

 p. 44) recognizes three species of Jer-Falcons, F. gyrfalco, F. candicans, 

 and F. is/audits. Nine years later Newton (Yarr. Brit. B. i. pp. 36-52) 

 does not suggest any alteration in this conclusion. Sharpe (Cat. Birds 

 Brit. Mus. i. p. 410), in 1874, admits the validity of the two first-men- 

 tioned species, but splits the last-mentioned into two, F. islandus and F. 

 hulbceUi. In the same year Baird, Brewer, and Ridgway (Hist. N. Arner. 

 Birds, iii. p. 108) only recognize one species, which they subdivide into 

 five varieties. F. yyrfalco is split into var. sacer, var. gyrfalco, and var. 

 labradora; F. candicans is called var. candicans; and F. islandus and F. 

 holbcelli are united under the name of var. islandicus. In 1876 Dresser 

 (' Birds of Europe/ vi. pp. 15-30) reunites var. sacer and var. gyrfalco 

 under the name of F. yyrfalco, but admits the distinctness of F. labradorus. 

 F. candicans is recognized as a good species, but F. holboelll is reunited 

 with F. islandus under the latter name. 



The characters upon which these alleged species are based are very 

 variable, and the localities of examples in various museums are very inexact. 

 In the literature of the subject still more uncertainty prevails, in conse- 

 quence of wrong determination of immature birds; but after making 

 allowance for these supposed errors, the following appears to me to be the 

 most rational solution of this puzzling problem. 



We may at once dismiss -F. labradorus as a perfectly distinct species, of 

 a nearly uniform brown colour in the adult, with a few buff streaks on 

 the flanks, and a perfectly brown tail. This species breeds in Eastern 

 Labrador ; and there seems to be no evidence of any kind that any inter- 

 mediate fornis/>ccur between it and F. gyrfalco. 



F. candicuns is the arctic form, breeding only north of the arctic circle, 

 in North Greenland, and Eastern America north of Hudson's Bay. No 

 Jer- Falcon has ever been found breeding in North Russia or Siberia. The 



VOL. j. c 



