Birds
Kagu
Rhynochetos jubatus · also called kagu, cagou, ghost of the forest
The kagu is a bird found nowhere on Earth but New Caledonia — a slow, pale, ground-walking forest bird with a punk crest, red legs, and skin flaps over its nostrils that no other bird possesses. It cannot really fly, it barks like a dog at dawn, and until people arrived it had essentially nothing to fear.
Overview
The kagu lives only on Grande Terre, the main island of New Caledonia, in humid closed-canopy forest and shrubland, mostly in the mountainous interior. It is ground-dwelling, active by day, and forages by standing motionless, listening for prey moving in the leaf litter, then stabbing down with its orange bill. Pairs hold territories for life and announce them with a loud dawn barking duet.
An island bird that gave up flight
New Caledonia had no native land mammals and no ground predators, so the kagu, like many island birds, stopped investing in powered flight — but unusually it kept full-sized wings and its flight muscles. It uses them to glide downhill, balance while running, and flash bold wing barring in display. It just cannot take off.
Features found in no other bird
- Nasal corns — skin flaps over the nostrils, probably to keep soil out while probing the ground
- A relatively low body temperature and low metabolic rate
Slow to breed
The kagu lays one egg a year. Both parents incubate and raise the chick, and grown offspring often stay to help with later broods.
Status
The kagu is Endangered but increasing — around 1,000–2,000 birds and slowly rising. It was nearly wiped out by dogs (the main killer of adults), cats, pigs, and rats (eggs and chicks), and by mining, logging, and fire. Sustained predator control, captive breeding, and reserves since the 1980s have reversed the decline, though the bird remains wholly dependent on that effort.
Kagu: common questions
Why can't the kagu fly?
The kagu evolved on New Caledonia, an isolated island that until humans arrived had no native land mammals and no ground predators. In that setting, the costs of powered flight — building and fuelling large flight muscles — outweighed the benefits, so the kagu, like many island birds, reduced its investment in flight. Unusually, though, it kept full-sized wings and did not lose the flight muscles entirely. It still uses the wings to glide down slopes, to keep its balance while sprinting after prey, and to flash the bold black-and-white barring on the flight feathers during its courtship and threat displays. It simply cannot take off and stay up.
What are the kagu's "nasal corns"?
They are small flaps of skin, one over each nostril, and no other bird in the world has them. Their function is not certain, but the leading idea is that they act as covers that stop dirt and debris from being forced into the nasal passages when the kagu drives its bill into soil and leaf litter to grab prey. The kagu hunts by standing still, cocking its head to listen for a worm or an insect moving under the surface, and then stabbing down suddenly, so keeping its airways clear during that action would be useful.
Why is the kagu called the "ghost of the forest"?
Partly for its appearance — a pale, ash-grey bird that moves quietly and slowly through dim closed-canopy forest and can seem to appear and vanish. And partly for its voice — pairs perform a loud, resonant, barking duet at dawn, an eerie rolling sound that echoes through the forest before the birds themselves are seen. The Kanak people of New Caledonia have long featured the kagu in stories and dances, and its call was used as an identity signal on Radio New Caledonia.
Why is the kagu endangered, and is it recovering?
The kagu declined severely after Europeans arrived with dogs, cats, pigs, and rats. Dogs are the single biggest killer of adult kagu — a ground bird that freezes or displays rather than fleeing has no defence against a dog — while cats, pigs, and rats take eggs and chicks, and pigs also destroy the forest floor. Nickel mining, logging, and fire have fragmented its habitat. Numbers fell to perhaps a few hundred. Since the 1980s, sustained dog and pig control, captive breeding and release, and protected reserves such as Parc de la Rivière Bleue have turned the trend around, and the population is now slowly increasing, though the bird remains Endangered and dependent on that management.