During nest-building, the female alone enlarges the tree hole and cleans it of humus and leaves, while the male, perched nearby, makes clucking noises. He brings earth to seal the tree hole with the female inside. He may make up to 20 trips a day. The nest entrance is plastered over with mud and droppings, leaving only a narrow slit. The incarcerated female and chicks are entirely dependent on the male for food.
Extinct in Singapore by 1855, the species made a surprising comeback in 1994, first on Pulau Ubin and then on mainland Singapore. The bird is re-establishing healthy colonies here, thanks to our collaborative efforts with NParks, Nanyang Technological University and Singapore Avian Conservation Project.