崇明东滩自然保护区越冬白头鹤警戒行为的观察

Vigilance Behavior of Grus monacha in Dongtan Nature Reserve of Chongming,Shanghai

2007年1月至2月和2007年11月至2008年2月,利用焦点动物取样法和瞬时扫描法对上海崇明东滩自然保护区越冬期白头鹤(Grus monacha)的警戒性进行了观察。通过集群大小与警戒个体比例,说明鸟类越冬集群的生物学意义,同时研究了鹤类对人类不同干扰类型的耐受性。结果表明:白头鹤集群大小对群中个体警戒时间和警戒个体比例均产生显著影响(P<0.05)。集群中个体警戒时间和警戒个体比例均随集群增大而减小。当鹤群数量超过90只时,警戒个体的比例降到最低(x-=17.8%),此后保持恒定。白头鹤在农田生境中的警戒观望距离为(408.8±43.3)m,在滩涂生境中为(378.6±32.5)m。白头鹤对人类和机动车(船)的观望距离间存在显著差异(P<0.05),对人类活动敏感,而对机动车(或船)的警惕性次之。在人类二次干扰条件下,白头鹤的观望距离(F=11.797,P=0.003)、躁动距离(F=44.058,P<0.001)和逃逸距离(F=130.035,P<0.001)均显著增加,其中逃逸距离增加最多。

An experiment was conducted to study the biological significance of avian flocking in winter and the endurance capability of crane to human disturbances in terms of flock size and vigilant individual percentage. Observations on the vigilance behavior of Hooded Crane （ Grus mortacha ） in Dongtan Nature Reserve of Chongming Island, Shanghai were conducted from January to February 2007 and from November 2007 to February 2008 by the methods of focus sampling and instantaneous scanning sampling. Results showed that the flock size of Hooded Crane affected both the scanning duration and vigilant individual percentage significantly （ P 〈 0. 05 ）. The scanning duration and vigilant individual percentage decreased with the increase of flock size. When the flock size was more than 90, the vigilant individual percentage dropped to its lowest value and kept stable with the flock size growing. The watching distance of Hooded Crane in farmland habitat was （408.8 ± 43.3） m, and that in tideland was （ 378.6 ± 32.5 ） m. There was a significant difference between the watching distances of Hooded Crane to human and motor transporters （ P 〈 0.05 ）. Hooded Crane hold a more sensitive vigilance distance to human than to motor transporters. When redisturbed by human, the watching distance, dreading distance, and fleeing distance of Hooded Crane increased significantly.