magpies

Now and than a magpie would call.

有喜鹊的叫声。

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

建议选择野鹭类、麻雀和喜鹊等鸟类作为指示物监环境中的重金属污染。