The large forest hornbills live a caring sharing life.
The birds pictured are actually two males (probably young adults as the casque is developed but lacks the complete two-tone pattern of mature males).
These birds are long-lived and form life-long partnerships. Females need to know that they can fully rely on their guy as during breeding the female is "bricked -up" into a tree-hole using dried mud/fruit puree/droppings. Here she lays & incubates whilst her partner brings her and her youngster all of their food. When the single youngster is large enough the female is broken out of jail and both adults continue to feed junior.