鳴いている

is chirping

→ 鳴く
phrase Rare #42,158
is chirping Used for animals, birds, and insects that are currently making sounds. Depending on the animal, it can also mean “is singing,” “is calling,” or “is crying.”
JA: 庭で猫が鳴いている。
EN: A cat is meowing in the garden.

たくさんの虫が野原で鳴いている

Many insects are chirping in the field.

に違いないというのは鳥が鳴いているから

It must be morning, because the birds are singing.

の上で鳥が楽しそうに鳴いている

A bird is chirping happily in the tree.