Hornbills are cavity nesters with a fascinating reproductive process. A mated pair works together to seal a nest, leaving only a narrow slot just large enough for the female to squeeze into. Once the female is inside the nest, the male forms special pellets of mud and saliva in his gullet to seal the entrance. The female and eggs live inside the nest until the eggs have hatched and the chicks are about half grown. The female then breaks out of the nest where she and her mate return food to the chicks through the slot. The chicks break free when they are able to fly.

This picture was taken of a male gathering up one such pellet. This was a very cool moment to witness.