The largest and most widespread heron in north america .
这种苍鹭在北美分布最广，而且个头最大。
The heron is one of the uk 's largest native birds and grey herons are also common around garden ponds .
鹭是英国最大本土鸟类之一，苍鹭也经常出现在池塘。
A great blue heron holds a small fish after catching it in a pond in roseburg , us
在美国罗斯堡（roseburg）的一个池塘中，一只大蓝苍鹭叼着一条刚抓到的小鱼。
Hong kong closed its mai po nature preserve as a precaution for 21 days from friday , after a dead grey heron found there also tested positive for bird flu .
