The common cuckoo (Cuculus canorus), a bird known for its distinctive call and brood parasitism (laying eggs in other birds' nests).
山道でカッコウの鳴き声を聞いた。
I heard the cuckoo's call on the mountain trail.
カッコウは托卵をすることで有名だ。
The cuckoo is famous for laying its eggs in other birds' nests.
春になるとカッコウが鳴き始める。
When spring arrives, the cuckoo begins to call.