鳴く
なく · naku · JLPT N5 · verb-godan
to make sound (animal)
🐦🐱 鳴 = mouth 口 + bird 鳥: a bird opening its mouth to call
The kanji 鳴 joins 口 (mouth) and 鳥 (bird), so the meaning is built in: an animal voicing its call. Naku sounds the same as 泣く (to cry), so one sound covers both: people 泣く, animals 鳴く.