A rare, poetic name for the lesser cuckoo (Cuculus poliocephalus), also known as 時鳥 (ほととぎす). Used mainly in classical or literary contexts.
See also: ホトトギス
The name 恋し鳥 sometimes appears in old waka poems as an alternate name for the lesser cuckoo.
The exact derivation is uncertain; the spelling 恋し鳥 literally means 'longing bird', likely a poetic association with the cuckoo's call.