Why does a hornbill seal its nest?
In many hornbill species, the female enters a tree cavity and seals the entrance until only a narrow slit remains.
Anatomy, feeding and habitat
A wall made from mud, fruit pulp, droppings and plant material makes predator entry difficult. The male passes fruit and small animals through the slit to the female and chicks. The female may molt while incubating inside. The timing and individual that breaks the seal differ among species. A bird's bill, feet, wings and feathers offer clues to feeding and movement, although one structure can serve several functions. Flight depends on muscles, body proportions and weather as well as wing size. Season, age and molt may change appearance.
Behavior, reproduction and conservation
The system improves security but makes the family highly dependent on reliable food delivery by the male. Cutting old trees with suitable large cavities limits nesting. Hornbills carry large fruit seeds over distance and contribute substantially to tropical forest regeneration. Breeding timing relates to food and climate, and nest success from one year is not generalized. Light pollution, glass collisions, habitat loss and invasive species affect birds differently. Conservation includes feeding, resting and migration sites as well as nests.