北京地区黑鹳越冬期的取食行为

2004年12月至2005年3月在北京十渡地区的二渡和涞水县野三坡两地采用目标取样法对越冬期黑鹳(Ciconia nigra)的取食行为进行了观察。每星期观察一次,累计观察246 h。黑鹳觅食处水深5~40 cm左右,以鱼类和螺类为食,其中鱼类占90%以上;平均每小时进食20次左右,黑鹳在两个研究地点取食的食物没有差别(P=0.439>0.05)。黑鹳取食长度小于4 cm的鱼类最多,占取食总次数的65.0%。成体和亚成体对不同大小鱼类的取食比例无差异(小于4 cm的鱼类,P=0.513>0.05;5~8 cm,P=0.979>0.05;≥9 cm,P=0.657>0.05)。在成体与亚成体对不同体型鱼类的搜寻时间中,成体搜寻较小食物的时间短于亚成体(P=0.008<0.05)。对食物的处理时间随着鱼类大小递增而延长,亚成体在处理较小食物上花费的时间相对较长(小于4 cm的鱼P=0.002<0.05;5~8cm的鱼P=0.001<0.05),表明亚成体的取食经验不足。保护越冬期黑鹳的最佳对策是减少对其取食活动和取食地的人为干扰。

Foraging Behavior of Wintering Black Stork in Beijing

Foraging behavior of the Black Stork(Ciconia nigra) during winter was studied from December 2004 to March 2005,at Er-du and Yesanpo in Shi-du area, Beijing.Data on food items and searching and duration on handling food between adults and sub-adults were collected once a week,the observation period was accumulatively 246 hours.The results showed that the Black Stork searched their food at shallow water about 5-40 cm in depth and more than 90% of their food were fish.Only less than 10% of their food was formed by molluscs.The food catching frequency was around 20 times per hour,and the food component was similar between sub-adults and adults(P=0.439>0.05).Fish less than 4 cm in length made up 65.0% of their food in both adults and sub-adult(P=0.513>0.05).No Adults spent less time searching smaller fish(less than 4 cm in length) than sub-adults did(P=0.008<0.05),but no difference was found between adults and subadults in searching larger fish(larger than 4 cm).The handling time increased with the fish size,however,the sub-adults spent a longer time in treating smaller and medium size fish(P=0.002<0.05 and P=0.001<0.05) than adults.The best protection strategy for wintering Black Stork is to reduce the human disturbance on feeding activity and foraging habitat.