Joint defense against a common enemy was noted on July 21, 1961, when 21 kites were seen swooping at a Swainson's hawk perched near the top of a large cottonwood, where it was partly protected by foliage and branches. When I flushed the hawk, it was pursued and harassed by the kites, some of which followed it for nearly a quarter mile although there were no nests of the kites nearby. On August 4 a group of six kites was seen heckling a fledgling Swainson's hawk, which crouched among thick foliage in the top of a tall cottonwood, as the kites swooped at it, sometimes brushing it with their wings when they swept past. Dr. Hibbard mentioned an instance in which a horned owl was flushed, and was chased and heckled by a red-tailed hawk and by a group of kites. The latter seemed to regard the owl as the greater enemy, but ordinarily any large raptor arouses their hostility. Because of their exceptionally swift and skillful flight, the adult kites have few natural enemies, but the eggs or nestlings are vulnerable to such enemies as crows, jays, the larger hawks and owls, and to certain mammalian predators, notably raccoons. Also, many nests probably are destroyed by the sudden and violent summer storms that are characteristic of the High Plains. Bendire (1892:178) cited observations by Goss that in a hailstorm in Barber County, Kansas, eggs were destroyed in many kites' nests and some of the nests were almost completely demolished. Several nests found by me to have incubating eggs in the first week of June were abandoned or had disappeared completely by July 18, but the cause was not evident. One nest that was under observation on July 22 had nestlings approximately two-thirds grown on that date, but on August 4 only a few sticks remained, and the carcass of a fledgling dangled from a limb ten feet below the nest. Even at the Park where firearms are prohibited, kites are sometimes shot by ignorant or malicious persons. In general, Kansas ranchers recognize the harmless and beneficial habits of kites, appreciate their esthetic appeal and protect them, but many persons use them as convenient targets, with utter disregard for the Federal laws protecting them. Because of the strong popular prejudice against raptorial birds in general, laws protecting them are usually not enforced. Law enforcement officers do not take action even when clear-cut violations come to their attention. Arrest and prosecution for the killing of any kind of raptor is almost out of the question in Kansas. Ratio of Immatures to Adults