一項研究發現，全球多種鳥類都使用幾乎相同的警報聲，來保護巢穴免受巢寄生鳥的侵害。巢寄生鳥是指那些將卵產在其他鳥類巢中，並由寄主代為撫育幼鳥的鳥類。研究指出，來自四大洲的二十多種鳥類都會發出這種警報聲，而且牠們彼此之間從未接觸過。這項研究顯示，鳥類會透過這種訊號合作驅趕巢寄生鳥，而這種警報聲在巢寄生鳥危害最嚴重的地區尤其常見。

A recent study found that diverse bird species around the world use a nearly identical alarm call to defend their nests against brood parasites—birds that lay their eggs in the nests of other species instead of raising their own young. More than 20 bird species across four continents use this alarm call, despite never having come into contact with one another. The research shows that birds cooperate to drive away brood parasites through this shared signal, and that the call is especially common in regions where brood parasitism poses the greatest threat.

https://scitechdaily.com/scientists-find-a-global-language-hidden-in-bird-calls/