The kagu forages by pressing its long, slightly downcurved bill into soil and leaf litter to locate earthworms, snails, and insects. Above each nostril sits a nasal corn: a raised, unfeathered flap of skin that can be moved to cover the nostril opening. Researchers who describe the structure link it to keeping soil, moisture, and debris out of the airway during repeated digging, a plausible but not fully tested explanation.
The kagu is the sole living member of its family, Rhynochetidae, and one of only two species historically placed in that lineage worldwide. Its wild population is small and fragmented across New Caledonia's forests, and the species is listed as Endangered, with introduced predators such as dogs, cats, and rats identified as major threats to eggs and flightless chicks.
What remains uncertain is how much protective benefit the nasal corns actually provide compared with other possible functions, such as sensory or structural roles, since the anatomy has been described more often than experimentally tested. The kagu is also frequently mislabelled simply as 'flightless'; it retains wings and can flutter or glide short distances despite rarely flying.