海南岛尖峰岭热带山地雨林林下鸟类群落研究

从 2 0 0 0年 5月到 2 0 0 2年 3月 ,用网捕法对海南岛尖峰岭热带山地雨林 (包括原始林和次生林 )林下鸟群落进行研究。共张网 3 992 .7网· h,捕到林下鸟 3 12只 40种 ,隶属于 6个目 11个科。林下鸟群落虽然以小于 2 5g重的雀形目鸟类占优势 ,但许多个体较大的非雀形目鸟类也到林下活动 ,最大个体重达 3 70 g,大于 10 0 g重的个体占整个林下鸟生物量的比例较大。尖峰岭热带山地雨林中的林下鸟以食虫鸟为主 ,食虫鸟占整个林下鸟种数的 70 .0 %、鸟数量的 77.56% ;食果鸟虽然占第 2位 ,但其所占比例较小。林下鸟的种类组成和密度存在季节变化。留鸟是林下鸟最重要的成分 ,留鸟占鸟类种类的比例超过 85% ,留鸟的捕获数量占整个捕获鸟类数量的比例超过 90 % ;迁徙鸟的种类和数量均较少 ,对林下鸟群落的季节变化影响不大。原始林与演替 40 a后的次生林林下鸟平均网捕率相近但林下鸟群落种类组成不同 ,其种的相似性仅为 0 .3 5。

A study of understory bird communities in tropical mountain rain forest of Jianfengling, Hainan Island, China

Understory birds were sampled by mist-nets in tropical mountain rain forest (including secondary and primary) of Jianfengling, Hainan Island from May 2000 to March 2002. A total of 312 individuals of 40 species representing 11 families, and 6 orders were captured. The species and captures of Passeriformes less than 25 g in mass constituted the largest component of understory birds, accounting for 30.0% of total species and 50.32% of total captures respectively. However biomass of these species was less than the biomass of species of 25~50g weight or more than 100g weight. Many species of non-passeriformes often visited the understory strata, with the heaviest individual being 370 g. Understory birds belonged to various taxonomical species. Understory insectivorous birds formed the most dominant group with 70.0% of all species and 77.56% of all captures in tropical mountain rain forests of Jianfengling. Though understory frugivorous birds formed the second richness group, it consisted of species of Pycnonotidae and Columbidae and accounted for a small part of the community (10.0% of species and 10.90% of captures). This paucity of frugivorous species contrasts with the rain forests of America and Africa where frugivorous birds are abundant. Grey-Cheeked Fulvetta (Alcippe morrisonia) was the most dominant insectivorous species of understory communities, accounting for 37.88%, and 29.44% of all captures in primary and secondary forests respectively. The White-throated Bulbul (Alophoixus pallidus) was the most dominant frugivorous species in both primary and secondary forests. The density of understory birds fluctuated seasonly. There was greater density in dry seasons than in rainy seasons in primary forest, but almost the same density between dry seasons and rainy seasons in the secondary forest. The composition of understory birds varied seasonly with only a few species being captured across seasons in both primary and secondary forests. Resident birds constituted more than 85% of all species and 90% of all captures in communities. Only 5 species were migratory birds (wintering in Hainan Island):Rufous-tailed Robin (Luscinia sibilans), Red-flanked Bush Robin (Tarsiger cyanurus), Scaly Thrush (Zoothera dauma), Grey Thrush (Turdus cardis) and Fukien Niltava (Niltava davidi). The number of migratory birds accounted for 7.37% of all captures and had an insignificant effect on seasonal changes of bird densities of understory birds. The results showed a similar mean capture rate of birds in between primary and secondary forests, but composition of species were different and Jaccard's similarity index was only 0.35.