青藏高原常见雀形目鸟类的筑巢特征

Nesting Ecology of the Passerines in Qinghai-Tibetan Plateau

于1990—2004年的繁殖季节,在青藏高原北部地区收集了12种常见的雀形目鸟类的巢,并且对这些鸟巢的分布格局和结构特征进行了比较研究。所有鸟巢分布表现出草地、灌木丛和沼泽的水平分割和地上、地面及地下的垂直分割的空间分布模式,其中地面杯状巢最普遍。巢结构特征,存在从简单到复杂的系列谱变化,主要表现:巢形状从浅到深,从开放到封闭;巢材性质从单一的植物性到复合的动植物性;巢材重从少到多。不管这些变化有多大,都反映了所有鸟种选择巢址是在安全和隔热两种基本条件之间权衡。在变化谱上的每种鸟巢都有自己的利弊,选择哪种类型的巢是由鸟本身的遗传和环境特征两方面的因素决定的。另外,巢材的运输反映了亲鸟对筑巢活动的投资,是繁殖投入的重要组成部分。因此,巢材重与亲鸟体重之比可以反映出筑巢活动投资的高低。百灵科鸟的开放式地面巢材重大约是亲鸟体重的1/2;而褐背拟地鸦的地下封闭巢的巢材重约为亲鸟体重的5倍以上。其余种类都在两者之间变化。总之,如此不同的投资差异是在捕食压力和种间竞争作用下以及亲鸟为满足鸟卵胚胎和雏鸟迅速生长发育的必要条件下,各种生物学特征协调的结果。

Nesting is an important component of parental effort in birds. During the breeding seasons from 1990 to 2004, we surveyed the nests of twelve passerines and compared the distribution patterns and architecture traits of nests in Tibetan Plateau. The nest sites of twelve passerines have obviously different spatial patterns and can be categorized into overground, ground and underground types, among which most passerines nestings are ground type. The architecture of nests diversifies from simple to complex spectrum, showing from shallow to deep shape, open to close nest, single and little plant materials to multiple material of animal and plant. Despite these differences, we suggest that the nest choice of passerine in alpine meadow based on the trade-off between security and heat insulation. Every nest type in spectrum has own advantages and disadvantages, and genetic and environmental factors confine what kind of nest type passerine adopts. In addition, carrying nest material, as a parental effort, is an important component of reproductive investment. The ratio between mass of nest material and parent reflects the extent of nesting investment. The nest material of larks, which have open and ground nests, accounts for half of parental mass, but nest material of Pseudopodoces humilis, nesting underground, is 5 times of parent mass. Rest ratios of passerine lie in this range. In general, those investment diversities are the results of interactions of many biological traits to meet embryo and nestling development under the predation pressure and interspecies competition.