magpies

Now and than a magpie would call.

不时有叫声。

Herons (Ardeidae), sparrows (Passerinae) and common magpies (Corvidae) are suggested as useful bioindicators of environmental pollution.

建议选择野生鹭类、麻雀和等鸟类作为指示生物监环境中重金属污染。