长江八里江江段江豚种群数量、行为及其活动规律与保护

POPULATION SIZE,BEHAVIOR,MOVEMENT PATTERN AND PROTECTION OF YANGTZE FINLESS PORPOISE AT BALIJIANG SECTION OF THE YANGTZE RIVER

198 9～ 1999年 ,在长江八里江江段对江豚进行了 2 8次往返观察和 8次定点观察。结果表明 ,近 10年八里江江段江豚种群数量逐年呈明显递减趋势 ,平均每年以 7.3%速率递减 ;1996年后 ,枯水季节江豚不再进行江—湖迁移 ,其活动范围仅限于 2 0km的长江八里江江段 ,较 1993年以前缩短了约 40km。江豚在八里江江段的行为多种多样 ,通过对江豚种群在八里江江段的集群、摄食、逃避、发情与交配、抚幼、歇息和玩耍行为的描述、比较和分析 ,认为长江八里江江段是江豚典型的摄食和抚幼场所 ,同时也是江豚大规模集群的适宜栖居地。提出加强八里江江段江豚种群常年监测的必要性 。

The authors conducted 28 round-trip surveys and 8 on-site surveys for observing Yangtze finless porpoise, Neophocaena phocaenoides asiaeorientalis at the Balijiang section of the Yangtze River from 1989 to 1999. Based on the surveys, the population of the porpoise declined by 7.3% annually on average at the Balijiang section during recent 10 years; After 1996, the porpoise no longer migrated between the Yangtze mainstream and Poyang Lake during the dry season, migration range was cut down 40 km.The paper also describes the porpoises' behavior in this section, including schooling, feeding, escaping, oestrus and mating, care-giving, resting and playing. The results suggest that Balijiang section be a typical feeding and care-giving site for Yangtze porpoises. The authors also provide suggestions for on-site conservation of the porpoises in this section.