Hornbills

These birds have the most amazing lifecycle.
Together the male and female select a nest hole high up in a tree and begin preparing the nest by plastering up the hole with mud and droppings.
The male plasters the hole from outside and the female works from inside
until only a small slit remains, creating a predator-proof nest. The female lays two to three white eggs and remains enclosed in the nest for three months incubating the eggs and caring for the chicks while the male
delivers food to her and to the chicks. The chicks hatch after 39-45 days. Once the chicks have their first feathers, the female breaks out of the nest chamber and joins the male in providing food for the young. The chicks remain in the nest for about 80 days and then break through the opening.
If anything happens to the male, then the female will starve.
This photograph shows part of the courtship ritual.