92 



THE NATIONAL GEOGRAPHIC MAGAZINE 



(Falco peregriniis anatum) 



The duck hawk, finest of the falcons of 

 our continent, hves in regions where cHfifs 

 furnish it aeries. Truly a master of the 

 air, it kills at will, and its food is composed 

 almost entirely of birds. 



Resting on a commanding perch or fly- 

 ing easily, the hawk, when its appetite is 

 aroused by some luckless bird, descends 

 with a rush of wings so swiftly as almost 

 to elude sight, and strikes its unfortunate 

 victim Hke a veritable thunderbolt. Ducks, 

 shore birds, robins, meadowlarks, flickers, 

 pheasants, grouse, pigeons, and many 

 others have been recorded as its victims. 



When it has tiny young, it obtains war- 

 blers, sparrows, and other small birds to 

 feed them. No form of bird is safe from 

 it, as it has been known even to capture 

 the agile chimney swift. A duck hawk 

 comes nearly every winter to the old Post 

 Office Department tower in Washington, 

 and lives on pigeons captured as they fly 

 over the grounds of the Smithsonian Insti- 

 tution or above the near-by buildings. 

 Mammals are seldom taken. 



The duck hawk usually places its nest 

 on a cliff, often in a spot where it is prac- 

 tically inaccessible. Occasionally it resorts 

 to large hollows in trees, or very rarely to 

 old nests of eagles or hawks. The only 

 nesting material consists of whatever rub- 

 bish may have accumulated on the chosen 

 site, this usually including bones and other 

 fragments from birds the duck hawk has 

 eaten. 



Three to five eggs are laid, four being the 

 usual number. These are creamy or yel- 

 lowish white, irregularly blotched, streaked, 

 or otherwise heavily marked with various 

 shades of bright brown. 



The parents are noisy during the breed- 

 ing season, uttering quick, cackling calls. 

 When their nests are approached, they 

 circle rapidly about, harrying unmercifully 

 other birds that chance to pass, and even 

 killing ruthlessly when enraged. 



The duck hawk nests from Alaska and 

 the west coast of central Greenland to 

 Baja California, Kansas, and Maryland. 

 In winter it ranges south to Panama. 

 Peak's falcon, Falco peregrinus pealci, a 

 darker race, nests on the Aleutian and 

 Commander Islands, coming south in win- 

 ter to Oregon. Allied races are found in 

 the other continents of the world. 



GYRFALCON "■ 

 (Falco rusticolus) 



This hunting falcon of the north in early 

 days was the type most prized by the dev- 

 otees of the sport of falconry. Swift in 

 flight and possessed of almost endless en- 

 durance, these birds were desired above 

 all other hunting hawks. 



They range far beyond the limits of tree 

 growth, apparently to the limits of land. 

 They become so accustomed to resting on 

 the ground or on rocks that in captivity 

 they actually seem to prefer such locations 

 to a perch. 



The gyrfalcons of North America ap- 

 pear to like birds better than other food, 

 capturing them ordinarily on the wing. In 

 the far north they often nest in the vicinity 

 of colonies of auks, great piles of whose 

 bones accumulate beneath the gyr falcon 

 homes. 



From Labrador to Alaska these falcons 

 are the scourge of the ptarmigan. They 

 also capture gulls, guillemots, shore birds 

 of various kinds, and snow buntings, as 

 well as lemmings and Arctic hares. On 

 St. George Island, one of the Pribilof 

 group in Bering Sea, Hanna records that 

 one winter gyrfalcons came in abundance 

 and nearly exterminated the little wren 

 and the rosy finches. 



The gyrfalcon nests on ledges on the 

 face of clififs, placing its eggs on accumu- 

 lations of its own pellets, or, where there 

 is woody vegetation, it sometimes occupies 

 nests of sticks. The eggs, usually three 

 or four, are creamy white, very heavily 

 marked with reddish brown, and are 

 among the most handsome eggs of their 

 group. Nesting may come in May in the 

 far north, so that the nests are frequently 

 hung with icicles. 



The races of gyrfalcons found in North 

 America are in some confusion because of 

 the considerable variation in color among 

 these birds. In Greenland there is found 

 the white gyrfalcon, Fa/co rusticolus candi- 

 cans, which alsO' has a dark phase in which 

 the plumage is mainly gray. This race 

 may breed also in eastern Arctic America, 

 and is casual in winter south to British 

 Columbia, Montana, and Maine. A darker 

 form, varying from gray to nearly black, 

 known as the black gyrfalcon, Falco rusti- 

 colus obsoletus, nests from Point Barrow 

 to Labrador, and in winter ranges south 

 into the northern United States. 



