【摘要】 <正> 本文是昌黎果区几种主要吃虫鸟繁殖习性研究的第二部分,包括灰顶红尾伯劳、黑枕黄鹂及斑啄木鸟。对这三种鸟我们观察的巢数虽并不多,但这类工作在国内来说还是很少,所以我们把观察的资料整理出来,提供有关同志们的参考。更多还原

【Abstract】 This paper presents results of our studies on the breeding habits of three of the more common insect-eating birds in the fruit-producing district of Changle, Hopei province.Ⅰ. Lanius cnstOtus ludonfnsis. Its nest is cup-shaped, made of dried grass, flexible twigs and roots, interspersed with cotton, mosses and feathers, and lined inside with finer grass. The nest is often placed in trees at a height of 6-9 meters from the ground. Nest-building requires about 4-5 days. The eggs average 22.4 × 16.3 mm in size and 2.9 gms in weight. A normal clutch contains 4-7 eggs. Incubation is carried out by the female alone. During this period, the female is often fed by the male, who brings insect foods to the nest. After hatching, the young are fed in the nest for about 13-14 days. Both the male and female share in feeding young. They make a total of 114-153 visits to the nest every day. The male makes almost double as many visits as those made by the female.Ⅱ. Orolus chinensis diffusus. Its nest is cup-shaped, composed of grass-stems, papers, cotton, ect, placed between the twigs of a horizontal branch of a tree at a height of 4.45 meters from the ground. It measures 160 mm in diameter, 90 mm in depth. Nest-building requires about 4 days. The eggs average 29.5 X 22 mm in size. The full clutch consists of 2-4 eggs. Incubation is carried out by the female alone. After hatching, the young are fed for about 16-18 days. Both the male and female birds share in feeding the young. They make a total of 60-80 visits to the nest every day.Ⅲ. Dendrocopos major cabanisi. Its nest is built in a hole of a cherry tree, about 4 meters from the ground. The full clutch contains 5 eggs, which measure 18.5 × 26.8 mm in size. Incubation of eggs lasts for about 9 days. Both of the parents participate in incubation. After being hatched, the young are fed by the parents for about 25-26 days. During the feeding period, the parent birds pay 54-114 visits to the nest every day.The foods consumed by both the adult and the nestlings of the three species under investigation are all insects, among which are certain serious pests. They are, therefore, beneficial to agriculture and deserve our protection.更多还原