Читать книгу Life Histories of North American Jays, Crows, and Titmice - Arthur Cleveland Bent - Страница 25
ОглавлениеHABITS
Dr. Oberholser (1921) has shown that the range of this race has been found to extend much farther north, including South Carolina, the type locality of Cyanocitta cristata cristata (Linnaeus), which, of course, necessitates the relegation of the subspecific name florincola and the common name Florida blue jay to synonymy. This would leave the northern blue jay without a name, for which Dr. Oberholser proposed the subspecific name bromia. The 1931 Check-list admits this extension of range as far north as North Carolina but entirely ignores the fact that the name C. c. cristata (Linnaeus) was based on Catesby’s bird, which undoubtedly represents this southern race.
I prefer to use Arthur H. Howell’s (1932) names, Cyanocitta cristata cristata (Linnaeus) and “southern blue jay,” for this race. He says that its range covers approximately the northern half of the State, at least as far south as Volusia and Lake Counties, where it probably begins to intergrade with the extreme southern form, semplei. W. E. Clyde Todd (1928), who described semplei, seems to think that specimens taken north of the Everglades are not typical of either race, thus allowing a large area of intergradation.
This race is smaller than the northern race, with coloration paler and duller and with the white tips of the greater wing coverts, secondaries, and tail feathers smaller.
Nesting.—The nesting habits of the southern blue jay are not very different from those of the northern blue jay, with due allowance made for the difference in environment. Major Bendire (1895) writes:
Two nests found by Dr. Ralph were placed in low, flat pine woods, 25 and 30 feet, respectively, from the ground; these were composed of twigs, Spanish moss, pine needles, and pieces of cloth, and lined with fine roots. In some of the nests the material were cemented with mud. A third nest was placed in an orange tree standing within a few feet of a house, near the banks of the St. John’s River, about 20 feet from the ground; it was composed of twigs, catkins, plant fibers, weeds, grasses, pieces of string, and a little Spanish moss, and these materials were cemented together with mud; the lining consisted entirely of wire grass (Aristida). Another nest was placed among some small branches at the end of a limb of an orange tree, about 11 feet from the ground, and was composed of similar materials outwardly, but no mud was used in its construction, and it was thickly lined with fine rootlets of the orange tree.
The average measurement of two nests is about 8 inches in outside diameter by 4 inches in depth, the inner cup measuring about 4 inches in diameter by 2¼ inches in depth.
Mr. Howell (1932) says that the “nests are placed in trees—commonly oak, orange, or pine—at a height of 8 to 35 feet above the ground”; and he quotes D. J. Nicholson as saying that two or three broods are raised in a season, beginning late in March and ending in August. There is a set of eggs in my collection, taken in Leon County, Fla., from a nest in a magnolia tree; it was made of materials similar to those mentioned above, including the mud.
In Texas, according to George F. Simmons (1925), the nests are placed in various oaks, hackberry, pecan, cedar elm, and cedar trees. Wayne (1910) says that in South Carolina it seems partial to live oaks.
Eggs.—The eggs of the southern blue jay are indistinguishable from those of its northern relative and probably would show in a large series all the wide range of variation in shape, color, and pattern exhibited in eggs of the northern blue jay. According to Mr. Nicholson (Howell, 1932), “the first sets nearly always comprised 4 eggs, the second sets either 3 or 4, the third sets nearly always 3.” The measurements of 40 eggs average 27.1 by 20.4 millimeters; the eggs showing the four extremes measure 29.6 by 20.7, 27.4 by 21.3, and 23.2 by 18.4 millimeters.
Food.—The feeding habits of the southern blue jay are similar to those of the northern bird; it lives on such varieties of nuts, wild and cultivated fruits, grains, insects and their larvae, and other small forms of animal life as it can find within its range. It is said to do some damage to small cultivated fruits and to rob birds’ nests of their eggs and young.
Dr. Walter P. Taylor tells me that in Walker County, Tex., these jays are useful in providing food for bobwhite quail, by dropping pieces of acorns that they have broken up.
Behavior.—Wherever I have been in Florida I have been impressed with the fact that the local blue jays are among the commonest and most familiar birds. They are not at all shy and seem to enjoy living in the towns and villages, in the gardens and trees close to houses, in the shade trees along the streets, and in the citrus groves, as well as in the open country. Mr. Howell (1932) says that they “are found less commonly in pine woods, hammocks of oak or mixed timber, turkey-oak scrub, and the borders of small cypress swamps. The birds are noisy and restless during the greater part of the year, moving about in small companies or loose flocks, calling vigorously as they go. While for the most part indifferent to the presence of man, they nevertheless retain a degree of caution and can scarcely be tamed enough to eat from one’s hand, as can the Florida Jays. They take great delight in worrying owls whose retreats they may discover, and their reputation for robbing the nests of smaller birds is rather bad.”
M. G. Vaiden writes to me from Rosedale, Miss.: “The blue jay is a very destructive bird to other small birds’ nests in this area; many times have I seen the blue jay in the act of destroying cardinal, mourning dove, mockingbird, and Maryland yellowthroat nests. My notes give an instance of the determined and persevering way these birds have when bent upon the destruction of another species’ nest. On May 5, 1928, a blue jay was caught in the act of robbing a cardinal’s nest located in a crape-myrtle bush in my front yard. He was sitting on the nest with one egg in his bill when first noticed. I secured a 22 rifle and shot very close to the jay; he flew away with the egg, yet returned in a short while for another; and three shots were made as close as possible to the bird, with no intention of hitting it, before it would leave the nest locality. After a short interval it returned again and five shots were made, each shot hitting very close to the bird, yet it hopped to the cardinal’s nest and secured another egg. The next shot made it leave, but it carried the second egg along, as with the first. I awaited his return, fired one shot which failed to make him fly away, so I proceeded to kill the bird with the next shot. The cardinals, both, produced only mild scolds toward the jay and failed at any time to put up a fight. The nest was left with the two eggs remaining, but the cardinals quit the nest after the following day.”