When will the three treasures breed

The three treasure birds have been breeding from May and continued until August.This bird is widely distributed, some are migratory birds, and some are left birds.Migratory birds usually enter the breeding place in spring, and will leave until September-October.During the breeding period, it is usually found in the cave of trees to make nests. It only breeds once a year. There are 3-4 eggs in one nest.