Rare alternate name for the lesser cuckoo (Cuculus poliocephalus), a bird more commonly known as 時鳥 (ほととぎす). The name 勧農鳥 (literally 'encourage-farming bird') reflects the belief that its call signals the start of the farming season.
See also: ホトトギス
The name 勧農鳥 can be found in old documents as an alternate name for the lesser cuckoo.