National Geographic : 1933 Jul
EAGLES, HAWKS, AND VULTURES GOSHAWK (Astur atricapillus) The goshawk, one of the fiercest and most destructive of our birds of prey, ex ceeding the large falcons in this respect, inhabits the forests of the north and of the western mountains. It comes south sporadically from the far north during winters when there is a failure of its food supply, but at other times seldom is seen except along our northern border. Its flight is swift and powerful, and I have seen it easily overtake grouse and other fast-flying birds on the wing. In the north the goshawk eats Arctic hares, lemmings, and ptarmigan. In its southern invasions it is the foremost enemy of the ruffed grouse, so that in the year following a goshawk flight there always is noted a decrease in these game birds. With these propensities, naturally this hawk is highly destructive to poultry, seiz ing chickens and boldly carrying them away. When its hunting instincts are aroused, it seems to lose all sense of fear, so that it will return for chickens even after having been stung with shot. It does not hesitate to attack other predatory birds and will fight with large owls until both combatants are killed. The goshawk builds bulky nests of sticks in either conifers or deciduous trees, but usually in heavy forest. The bird is fierce in defense of its home and will not hesitate to attack a human intruder. The eggs vary from two to five, with three or four as the usual number. They are pale bluish white, often unmarked, but sometimes with a few spots of brown. The call is a shrill note sharply repeated, being heard principally in the breeding season. The young in the first fall have the under surface streaked like the immature Cooper's hawk. Two races are recognized. The eastern goshawk, Astur atricapillus atricapillus, paler in color, breeds from Alaska, Quebec, and Nova Scotia south into British Colum bia and the northern United States, ex tending south as far as western Maryland. In its sporadic southern flights it comes into the Central States and irregularly into the Southwest. The western goshawk, Astur atricapillus striatulus, nests in the Pacific coast region from Alaska south to California and northern Mexico. HARRIS'S HAWK (Parabuteo unicinctus harrisi) This is a handsomely colored hawk, common only in a restricted area in the United States. Although accomplished in flight, so that it delights in turning in huge circles high in air, it is of quiet demeanor and often rests for hours on open perches from which it may survey the land. In southern Texas it is remarked fre quently on telephone poles along the high ways. In this region it is fairly tame and unsuspicious, often allowing automobiles to pass without taking flight, but in other areas it has been reported as wary. The call is a harsh scream, and the birds at times are quite noisy in the vicinity of their nests. Though in South America a closely re lated race has been reported consorting with vultures and caracaras and feeding on carrion, such is far from the case here. In Texas, Harris's hawk has been ob served dashing quickly through mesquite thickets, searching for wood rats and ground squirrels, and in southeastern Cali fornia Dr. Loye Miller found parts of a green-winged teal in the stomach of one, and bird remains, including a gilded flicker, in another. They are said also to eat lizards, and seem, on the whole, to be beneficial in their habits. The nests are composed of sticks, small branches, and weeds, lined with rootlets and grasses. They are placed in trees or sometimes on the tops of the Spanish bayonet or the giant cactus. From two to four eggs are deposited, these being dull white or with a faint greenish tinge, some without markings and some spotted irregularly with brown or lavender. The birds ordinarily offer no objection when their nests are ap proached, beyond uttering their usual calls and circling in the air overhead. The young differ from the adults in hav ing the under surface buffy white and broadly streaked with blackish brown. Harris's hawk is found in southeastern California, southern Arizona and New Mexico and the lowlands of south Texas, extending to Louisiana and Mississippi, and ranging south into Baja California and Central America as far as Panama. It has been observed casually in Kansas and Iowa. A related race is found in South America.