National Geographic : 1933 Jul
EAGLES, HAWKS, AND VULTURES BROAD-WINGED HAWK (Buteo platypterus) The broad-wing, smaller than the red shoulder and red-tail, lives in woodlands, where it is seen only by those conversant with its habits, as it perches usually under cover of the leaves. In soaring it fre quently rises until it is nearly out of sight. Swampy woodlands and broken country covered with forests are favorite haunts of this species, and as the trees are cleared it decreases in abundance. It is entirely inoffensive in its habits. Except in migration, comparatively few are shot, as most depart for the South be fore the season for fall hunting. The food is mainly mice and other small mammals, frogs, reptiles, and insects. It eats small fish occasionally, but seldom takes birds. Large caterpillars are a reg ular item in its diet. It is partial to grass hoppers, crickets, and large beetles, and has been known to eat centipedes. It must be considered beneficial and worthy of every protection. The nests of the broad-wing are con structed of twigs, placed in a large tree, often at a considerable elevation. Green leaves are often found in the nest, and some birds add fresh leaves to the nest lining nearly every day. The eggs range in number from two to five, with two or three as the usual number. They are dull grayish white, or occasionally greenish, spotted more or less extensively with dif ferent shades of brown and lavender. Occasionally these birds will dash at an intruder. I remember distinctly, as a small boy, the start that one of these hawks gave me by swooping at my head as I sat on a limb beside its nest, high above the ground, admiring the eggs and the nest construction. The ordinary call is a shrill, double-noted whistle high in pitch, which is accompanied by chattering, scolding notes. The birds vary considerably in color and markings and occasional individuals are found that are entirely black. The broad-winged hawk nests from cen tral Alberta, New Brunswick, and Nova Scotia south to the Gulf coast and central Texas. It migrates south to northwestern South America, wintering mainly from southern Florida and southern Mexico southward. Allied races are found in the islands of the Lesser Antilles. SWAINSON'S HAWK (Buteo swainsoni) Swainson's hawk lives in regions where tree growth is scant. Though strong in flight and delighting in soaring, it spends hours resting on some open perch where it may watch the country. Except when it has been unduly persecuted, it is tame and unsuspicious, allowing close approach without taking alarm. The food of this hawk is varied and in cludes more insects than usual in a bird of its size. It feeds extensively on grass hoppers in late summer and fall, and also eats mice, rats, lizards, snakes, frogs, and rabbits. Though on rare occasions it may attack poultry, it is considered one of the most valuable hawks in the West in its relation to agriculture. Swainson's hawk nests in trees or on cliffs, where its bulky home, composed of sticks, is often visible at a distance. The eggs, varying from two to four, are green ish white or yellowish white, spotted with brown and lavender, occasionally being without markings. HAWK AND SONG BIRD NEST IN SAME TREE In the regions of scanty tree growth in habited by these hawks, it is a regular oc currence to find an isolated tree with nests of several species of birds clustered in it. Western kingbirds and Bullock's orioles often nest within a few feet of the large structure made by Swainson's hawk, and all live in harmony. Indeed, the home of a kingbird has been found located among the coarse sticks in the base of the hawk's nest. In migration, both north and south, these hawks often gather in straggling bands, from 500 to 2,000 birds having been noted in such groups. This hawk, like some of its relatives, has distinct light and dark color phases, these being illustrated in the flying birds of the opposite plate. Swainson's hawk has three of the outer primaries with the inner webs cut out or indented near the tip, and the red-tail has four. This difference will always serve to distinguish these birds in the hand. This species breeds from British Co lumbia, Great Slave Lake, and Manitoba south to northern Mexico, and is found in winter in South America. Stragglers have been taken at many points in the Eastern States.