Underwater behavioral patterns of one Yangtze finless porpoise （Neophocaena phocaenoides asiaeorientalis） calf in captivity and those performed on the water surface by two calves in semi-natural environment were foc...Underwater behavioral patterns of one Yangtze finless porpoise （Neophocaena phocaenoides asiaeorientalis） calf in captivity and those performed on the water surface by two calves in semi-natural environment were focally followed and continuously recorded until one year postpartum to construct the ethogram. The results indicate that 1） the three calves could display diverse and active behavioral patterns; 2） soon after birth, patterns critical for survival appeared first; 3） playful and social patterns predominated the ethogram; 4） most of the patterns were alike across age classes; 5） most of the patterns appeared at the calves’ early life stage. It is possible that the above characteristics are adaptively shaped by the aquatic and social life of this subspecies.展开更多
Lipotes usually occurs in pairs or in small loose groups. The calves are born in March-April.The Finless porpoises are usually seen in groups of five or six individuals.The blowof Lipotes lasts 0.2--0.6 sec and that o...Lipotes usually occurs in pairs or in small loose groups. The calves are born in March-April.The Finless porpoises are usually seen in groups of five or six individuals.The blowof Lipotes lasts 0.2--0.6 sec and that of Neophocaena 0.2--0.5 sec. In Lipotes,a short divewould take 10--20 sec and a long dive up to 1--2 min (average value being 31 sec). InNeophocaena a long dive would reach a maximum of 65 sec with an average of 17.5 sec.Lipotes has a pair of functional eyes. The selective secondary atrophy of a number of eyemuscles and nerves and the position of the eyes in the head correspond with the physical con-ditions of the environments so that the field of vision is directed forwards and upwards. When pursued by motor boat, both species react with a long dive and a change of direc-tion under water. With the Baiji this would occasionally cause fatal injuries by thepropeller of the ship. Such a case seems much less often with Neophocaena. The populationof Lipotes is at present very small.In the stretch of the river (between Nanjing andTaiyangzhou) under exploration, we found scarcely more than one dolphin per 4 km. Thecause for its scarcity is mostly due to accidents or wounds caused by propellers.展开更多
基金National Basic Research Program of China(2007CB411600)National Natural Science Foundation of China(30730018)President Fund of Chinese Academy of Sciences(220103)~~
文摘Underwater behavioral patterns of one Yangtze finless porpoise （Neophocaena phocaenoides asiaeorientalis） calf in captivity and those performed on the water surface by two calves in semi-natural environment were focally followed and continuously recorded until one year postpartum to construct the ethogram. The results indicate that 1） the three calves could display diverse and active behavioral patterns; 2） soon after birth, patterns critical for survival appeared first; 3） playful and social patterns predominated the ethogram; 4） most of the patterns were alike across age classes; 5） most of the patterns appeared at the calves’ early life stage. It is possible that the above characteristics are adaptively shaped by the aquatic and social life of this subspecies.
文摘Lipotes usually occurs in pairs or in small loose groups. The calves are born in March-April.The Finless porpoises are usually seen in groups of five or six individuals.The blowof Lipotes lasts 0.2--0.6 sec and that of Neophocaena 0.2--0.5 sec. In Lipotes,a short divewould take 10--20 sec and a long dive up to 1--2 min (average value being 31 sec). InNeophocaena a long dive would reach a maximum of 65 sec with an average of 17.5 sec.Lipotes has a pair of functional eyes. The selective secondary atrophy of a number of eyemuscles and nerves and the position of the eyes in the head correspond with the physical con-ditions of the environments so that the field of vision is directed forwards and upwards. When pursued by motor boat, both species react with a long dive and a change of direc-tion under water. With the Baiji this would occasionally cause fatal injuries by thepropeller of the ship. Such a case seems much less often with Neophocaena. The populationof Lipotes is at present very small.In the stretch of the river (between Nanjing andTaiyangzhou) under exploration, we found scarcely more than one dolphin per 4 km. Thecause for its scarcity is mostly due to accidents or wounds caused by propellers.
文摘为弄清长江河口区江豚（ Neophocaena asiaeorientalis ）种群数量和分布情况，于2012年6月8-11日和2012年9月12-19日对这一水域作了2次较大覆盖面的目视考察和9次遗骸搜寻。6月的考察目击到江豚5群8头，9月的考察未目击江豚个体。依据样带法估算，长江河口水域6月份的江豚种群数量约为61头。全年共获得7头江豚遗骸，并搜集到其他5例死亡信息。对其中5头外表完整、特征保留良好的遗骸所作的鉴定结果显示，2头为长江亚种（ N. asiaeorientalis asiaeorientalis），3头为东亚亚种（ N. asiaeorientalis sunameri）。调查表明，崇明岛西端和青草沙附近水域是长江亚种活动的热点水域，可作为重点监护区域。
