THE BIRDS OF GREENLAND. 57 



96. White Gyrfalcon. (Falco islandus.} 



Breeds in North Greenland; common during winter in 

 South Greenland. 



97. Gray Gyrfalcon. (Falc* rusticolus.) 



Resident ; common in South Greenland, where it breeds. 

 The exact limits of the nesting-grounds of these two forms 

 of Gyrfalcon cannot, however, be definitely settled, as they 

 are considered as one and the same species. The following 

 data applies equally to both : 



Eggs laid from April 16 to May 27. Number of eggs in 

 a set, 3 to 4. 



98. Duck Hawk. (Falco pereyrinus anatmm) 



Not uncommon ; breeds in both North and South Green- 

 land. Eggs found from April 13 to June 15. 



99. Merlin. (Falco regulus.) 



A chance visitor off the coast. 



100. Kestrel. (Falco tinnunculus.) 

 A chance visitor off the coast. 



101. American Osprey. (Pandion haliaetus carolinensis.} 

 A chance visitor to North Greenland. 



102. Short-eared Owl. (Asio accipitrinus.) 

 Somewhat rare ; not observed north of 70. 



103. Snowy Owl. (Nyctea nyctea.) 



Fairly common, especially in North Greenland, where a 

 few pairs breed. 



