The diet of the African grey hornbill is largely made up of invertebrates such as beetles and grasshoppers. Small vertebrate prey, such as lizards and tree frogs are taken too. During the dry season the diet is supplemented with seeds and fruit. These birds have been known to follow larger animals to take advantage of the disturbed insects. They will also wait in groups at forest fires to catch the small animals that flee.

The nesting habits of Hornbills are unique. Τhe female seals herself in a tree cavity and leaves only a narrow slit through which the male will feed her and her chicks until they are nearly ready to fly away. This curious nesting behavior is a defense against predators such as snakes and martens.

There are no major threat to this species.