WHITE GYRFALCON 3 



Dr. Frank M. Chapman's (1899) study of a collection of 33 gyr- 

 falcons from Greenland shows much the same range of variation 

 from the lightest to the darkest forms. He says: "Four examples 

 are dark enough to be referred to F. r. obsoletus, one of them being 

 fully as dark as the darkest of three specimens from Ungava, Labrador 

 kindly loaned me by Mr. Ridgway, and warrant the addition of Falco 

 rusticolus obsoletus to the Greenland fauna. These birds are con- 

 nected with the lighter specimens in the series by finely graded stages." 



Nesting. — First-hand, reliable information on the nesting habits of 

 the white gyrfalcon is very scanty. A. L. V. Manniche (1910) found 

 five nests in northeastern Greenland, where candicans proved to be 

 the breeding form. He writes: 



I only succeeded in making relatively few observations regarding the breeding 

 of the Gyrfalcon. Only one of the nests found was accessible viz. that on Nordre 

 Orienterings. 



May 19th 1907 I shot an old female at this nest; judging from her exterior 

 she must have been sick, certainly from an inflammation of her oviduct. In her 

 ovary were found 5 rather developed eggs. She had very pale plumage and 

 orange-yellow feet. In the nest was lying a fresh egg, which on one side had a 

 crack caused by frost. Like the other eyries observed, this one was conspicuously 

 marked by heaps of excrements and remnants from the meals of the birds such 

 as pellets, bones and other remains of animals. It was placed only 10 meters 

 above the level of the sea on the northern side of the rock, which rises precipitously 

 and steeply from the Stormbugt. 



Judging from the enormous heaps of excrements the nest had certainly been 

 inhabited for many years. The bottom of the nest was formed only by the 

 excrements of the birds. 



A falcon flying out from this nest was observed July 14th in the same year, 

 so the male must within a short time have found another mate. 



The next spring the female falcon was observed at the nest already April 20th. 

 The breeding did, however, not commence before May 26th. 



I often passed the nest and thus had good opportunity to observe the breeding 

 falcon. 



She kept very close to the nest, and did not leave it, even if I approached 

 to the very side of the rock, only stretching out her neck to eye me anxiously. 

 The male used to sit on the projections not far from the nest. 



June 22nd I arrived together with two of my companions in a dogsledge at the 

 eyrie of the falcon, intending to secure the young ones now supposed to be 

 hatched. 



The 4 eggs were, however, not yet hatched, but I could plainly hear the hoarse 

 cries of the young ones within. The shells were still unbroken with exception of 

 one, that had an insignificant crack. I kept the eggs warm by putting them 

 under my sbirt against my body. 



Having sledged for some hours we arrived at my station at Stormkap, and here 

 I continued my brooding of the eggs in my sleeping-bag. 



The first of the young ones emerged on June 23rd the next three 24 hours later. 

 The time of incubation for this clutch of eggs was thus nearly 29 days. 



The female Falcon behaved very anxiously when I ascended the rock and she 

 very unwillingly left her nest. Several times she rushed swiftly and vigorously 

 towards the disturber. The male, which proved very cautious, left the rock, 

 when the female was shot. 



