National Geographic : 1933 Jul
EAGLES, HAWKS, AND VULTURES MEXICAN GOSHAWK (Asturina plagiata plagiata) Of graceful, rapid flight, this handsome species frequents groves of cottonwoods and other trees along streams in the open valleys, or in the foothills of the moun tains. It is migrant within our limits, appearing rather late in spring and mov ing south early in the fall. The birds are usually tame, as in the wild country they inhabit there is little to molest them. LITTLE ECONOMIC EFFECT CAN BE ATTRIBUTED TO THIS HAWK Lizards, abundant in its haunts, make up much of its food, and it feeds exten sively on large insects, including grass hoppers and large beetles, which are said to be seized expertly on the wing. At need this bird can fly with a dash and speed which approximate those of a falcon. It eats various mice and rats, and also kills rabbits and ground squirrels. It appears that this hawk is one of nega tive economic importance in the United States, and that, as an interesting species, it should not be disturbed or killed. The nests of this goshawk are placed in trees. They are usually frail in construc tion, and made of twigs plucked green, so that they are still covered with leaves; this makes them difficult to see, as they match the dense green foliage in which they are placed. The nests are shallow and con tain two or three eggs, the smaller number being more common. In color the eggs are pale bluish white, more or less stained from the nest lining of leaves; occasionally one is marked with a few spots of brown. This species, although not brilliantly colored, from its contrasted markings is one of the handsomest of the hawks in our limits, its comparative rarity lending interest to the naturalist. It is an active bird, with powerful flight that enables it to dash through trees or other cover with ease, turning at need with the greatest fa cility. The call is a peculiar piping note that has been likened to the sound made by the long-billed curlew. In the United States, the Mexican gos hawk is found in southern Arizona, south ern New Mexico, and the lower Rio Grande Valley, apparently being most com mon in Arizona. To the south it is found through Mexico, being replaced in Central America by a smaller race of paler color. MEXICAN BLACK HAWK (Urubitinga anthracina anthracina) The present form is another that enters the southwestern borders of the United States in a limited section, where it is an inhabitant of dense groves of trees. Though quiet and given to resting for long periods on some partly concealed perch, it is a bird of swift and active flight and rises at times to soar in the open air, being par ticularly sportive in spring. The nest is a large structure of sticks that is frequently occupied year after year. It is often placed in a cottonwood or in a pine from 15 to 60 feet from the ground. Part of the sticks used for nesting material may be gathered on the wing, the bird dropping gracefully, sometimes from high in the air, to seize a dead branch in some tree top, snap it off, and carry it away without pausing appreciably in its course. From one to two eggs are deposited, being grayish white with a slight greenish tinge, spotted with brown and lavender. In the north the birds rear but one fam ily each season, but in the Tropics, if one set of eggs is taken, they often continue their domestic duties with a second or even a third nesting. In British Honduras, where these hawks are common and are little molested, they are said to be very bold, sometimes perch ing only five or six feet away while their young are being examined. The food of these birds, from what little has been recorded, seems somewhat varied. They are said to eat a good many snakes and lizards, and also to consume frogs and fish. Sometimes they pursue birds, and along the coast of Central America they are reported to live to a con siderable extent on crabs, large land crabs being favored food. They are said also to eat rodents of various kinds and large insects. They are too rare within our limits to have any particular economic status, but should not be destroyed wantonly, as they are interesting and peculiar, and represent a group not otherwise found in our fauna. The call of this bird is described as high pitched and quavering. The species is found from southern Ari zona and the lower Rio Grande Valley in Texas south into Central America, being mainly migratory in the United States. Al lied forms are found in tropical America.