South China Institute of Endangered Animals,Guangzhou 510260,China;2.Institute of Environment Science,Zhongshan University,Guangzhou 510275, China;3.National Jianfengling Nature Reserve,Ledong 572542,China
In order to study spatial movements of understory birds,mist nets and point counts were used in primary tropical mountain rain forest (PTM),secondary tropical mountain rain forest (STM),secondary tropical evergreen monsoon forest (STE) and secondary tropical semi-deciduous monsoon forest (STS) of Jianfengling,Hainan Island from May 2000 to March 2002. Sampled sites have a range of sea level from 190 m to 1 025 m. A total of 137 species were recorded. Red-flanked Bush Robin (Tarsiger cyanurus),Grey Thrush (Turdus cardis),White-crowned Forktail(Enicurus leschenaulti),Rufous-necked Scimitar Babbler (Pomatorhinus ruficollis),Goulds Fulvetta (Alcippe brunnea) and Grey-cheeked Fulvetta (Alcippe morrisonia) often act under 3 m forest. Though White-throated Bulbul (Alophoixus pallidus) mainly acts in range 3.1-10.0 m height,it often feeds under 3 m. Silver-breasted Broadbill (Serilophus lunatus) has never been seen under 3 m in the field,but it often is captured by mist nets because of flying way bellowing 3 m. So,these birds are the target species of movement study in the paper. A total of 428 individuals of 41 species were banded and 32 individuals of 8 species were recaptured during 6 426 net-hours. Total recapture rate was 7.5%. Grey-cheeked Fulvetta was recaptured most often,representing 43.8% of recaptured individuals. Of all species,Grey-cheeked Fulvetta moved the farthest (up to 1 150 m) from its banding location. Understory insectivorous birds form the most dominant group in tropical forest of Jianfengling. Among insectivorous birds,Silver-breasted Broadbill,Grey-cheeked Fulvetta and Goulds Fulvetta moved furthest,their mean distance of movement were 650 m,582 m and 387 m respectively. Frugivorous birds,such as White-throated Bulbul and Green-winged Bulbul (Hypsipetes mcclellandii) often move near banding points. The mean distance moved by insectivorous birds (442.3 m,n=27) was longer than that of frugivorous birds. Vegetation types affect the movement of birds. The mean distances moved by birds in PTM,STM,STE and STS were 686.5 m (n=13),312.8 m (n=12),89.6 m (n=5) and 195 m (n=2),respectively. The mean distance of movement in PTM was highly significantly farther than that in STE (F3,28=5.05,P<0.01). The mean movement distance of birds was significantly related with the length of wings (r=0.84,P<0.05),but not significantly related with body weights (r=0.79,P>0.05). Because insectivorous birds have a large range of movement,continuous forest in Hainan Island must be protected in order to conserve these understory insectivorous birds. Silver-breasted Broadbill is the typical understory insectivorous birds and species of key protection of China. It distributes only in tropical mountain rain forests,not in STE and STS at Jianfengling. Its protection deserves considerably attention.