词条 | crossbill |
释义 | crossbill bird genus ![]() North America hosts a variety of crossbills. In fact, evidence suggests that the eight different varieties of the red crossbill (Loxia curvirostra) may actually be different species. Each has a slightly different call note, a variant of the hard “kip-kip” given in flight. There are also differences in diet and bill size, with different forms feeding on specific conifers; for example, the larger-billed varieties choose trees with larger cones. The stubby little red crossbill also eats insects (insect), buds, and berries and is particularly attracted to salt. The spruce-loving white-winged crossbill (L. leucoptera) occurs throughout the colder regions of the Northern Hemisphere. It wanders widely, but when it finds a good crop of cones, it may nest there, even in midwinter. An isolated variety of the species lives in the pine forests of Hispaniola. It utters a dry, rattling, mechanical trill in flight. Eurasian species include the Scottish crossbill (L. scoticus) and the parrot crossbill (L. pytyopsittacus). |
随便看 |
|
百科全书收录100133条中英文百科知识,基本涵盖了大多数领域的百科知识,是一部内容开放、自由的电子版百科全书。