5.
Kagu
(Rhynochetos jubatus)
EN
Overview
The Kagu is a highly unusual, almost flightless bird, which due to its startling ash-white plumage, is known locally as the ‘ghost of the forest’. The only representative of an entire taxonomic family, the Kagu resembles something between a small heron and a rail. It has a large crest, long legs, a peculiar ‘bark’, which can be heard over a mile away. It is endemic to Grand Terre, the largest island of New Caledonia and has been adopted as the national emblem. Sadly, following predation by dogs and habitat loss the Kagu is now listed as Endangered. The Kagu experienced a decline in numbers during the 1900s primarily due to predation by invasive species. Domestic dogs have historically been the main threat to the species along with cats and pigs.
Urgent Conservation Actions
Monitor genetic status of the species and minimize the risk of inbred subpopulations. Protect all known forest sites where Kagu is present.
Distribution
Island of Grand Terre, New Caledonia
Fact
The Kagu produces powder down, a specialised type of feather which disintegrates into particles. This powder helps to keep the bird dry and insulated in New Caledonia’s tropical climate.
Media from ARKive
ARKive video - Kagu - overview
ARKive image - Kagu egg in nest on the ground
ARKive video - Kagu chick
ARKive image - Kagu egg being measured
ARKive video - Kagu physical characteristics
ARKive image - Kagu incubating eggs on nest
ARKive image - Newly hatched kagu chick on nest
ARKive video - Kagu feeding
ARKive video - Kagu calling
ARKive image - Adult kagu with newly hatched chick
ARKive image - Kagu chick between 7 and 8 hours old, getting its first meal of a worm
ARKive video - Kagu territorial defence
ARKive image - Camouflaged kagu fledgling
ARKive video - Kagu courtship display
ARKive image - 6 week old kagu chick
ARKive image - Kagu parents leaving chick part-hidden while they forage
ARKive image - Close-up of an adult kagu
ARKive image - Kagu, front view
ARKive image - Kagu on earth mound
ARKive image - Kagu, side view
Evolutionary Distinctiveness
Order: Gruiformes
Family: Rhynochetidae
The Gruiformes traditionally comprise the cranes, crakes and rails as well as other terrestrial and wading bird families. The positioning of the Kagu in this order is debatable as it has features not shared by any other members of the order. One example of this is the possession of powder-down, which is formed from specialised feathers that disintegrate into particles. Some birds from other orders, like parrots, do possess powder-down, but it is not seen in any other Gruiforme. Indeed this incredibly unusual species has features unlike that of any other bird. It has nasal flaps over its nostrils and a unique blood composition. Unsurprisingly, the Kagu has been assigned to its own family: the Rhynochetidae. Researchers are divided as to the Kagu’s closest relatives. Following genetic studies, some suggest the Kagu is closest to the Gruidae and did not evolve until recently. Others hypothesise it has affinities with the Sun Bittern, the sole member of another Gruiforme family. Another group suggests it is closer to the Mesitornithidae, a family of near flightless birds, which are not in the Gruiforme order.
The tree below shows the evolutionary relationships between this species and all other birds. The colours of the tree indicate EDGE scores with the red shades indicating the higher priority species; the bright red leaves correspond to the top 100 EDGE bird species. Further information on every species can be found by zooming in to its leaf on the tree.
Description
Size: 
55cm
Weight: 700g – 1100g
This ghostly-looking bird has a uniform blue-grey and white plumage, which is highly unusual for a forest-dwelling species. It has a long and shaggy crest that is erected during display and possesses powder downs to help keep it dry and insulated in New Caledonia’s tropical climate. The large wings, when spread, reveal conspicuous black and white barring. In contrast to its pale plumage, the Kagu’s large bill and long legs are bright orange-red, whilst the eyes are a darker red. Unique among birds, the Kagu has ‘nasal corns’ that cover its nostrils. These structures gave rise to its name: Rhynochetos, as ‘rhis’ means nose, and ‘chetos’ means corn. The brown and fawn colouring of chicks gradually changes into the adult plumage within 2-3 years. Its voice varies from quiet hissing and rattling calls, to a ‘bark’ and can be heard a mile away.
Ecology
The Kagu is a practically flightless, ground-dwelling bird. Although this species lacks the muscles needed for flight, its wings are not reduced in size and can be used to glide. This species is exclusively carnivorous, feeding mainly on worms, snails, millipedes, insects and small lizards, which it finds by picking through the leaf litter. Kagus were thought to form monogamous pairs and breed in large, permanent, non-overlapping territories between up to 28 hectares in size, however more recent research has suggested that they utilise group territoriality as a form of cooperative breeding. The species is highly territorial, engaging in sometimes fierce confrontations accompanied by shrill screams. The simple ground-nest is constructed from layers of leaves mainly between June and December but can happen all year round. A single pear-shaped egg is laid, which both parents incubate for between around 35 days. Parental care lasts 3-4 months, and one chick is typically raised per year (dependent on productivity of habitat). The Kagu reaches sexual maturity at three years, but often stays within the parents’ home range for as long as ten years. A typical family group comprises one breeding pair and offspring of various ages, which assist with defending the nest.
Habitat
The Kagu occurs in a range of forest habitats, typically those that are dense and humid, although drier forest at low altitude are occupied within the centre of the island. During the wet season this species occasionally extends its range into closed-canopy scrub.
Distribution
This species is endemic to the French overseas territory of New Caledonia, where it is found on Grand Terre, the largest of the islands and the only mountainous. The highest populations occur within the lower forests of the protected Parc Provincial Rivière Bleue and Parc Provincial des Grandes Fougères, in the central mountain range of the southern part of the island.
Population Estimate
1,500-3,000
Population Trend
Stable
Status
Endangered
Threats
The arrival of Europeans on New Caledonia heralded a dramatic decline in the Kagu, as birds were highly sought after for pets and the lucrative plume trade during the early 1900s. The ground-dwelling bird made easy prey for the non-native mammals that were introduced during this period. Feral and domestic dogs now constitute the single greatest threat to this species. One study attributed 17 out of 21 fatalities to dogs, which roam widely hunting in forests located over 4km away and 1,000m higher in altitude than their home village. Cats also prey on Kagu, with the latter accounting for 55% of small nestling losses in a study from Rivière Bleue Park. Feral pigs are also known to opportunistically eat clutches of eggs. Kagu habitat has been degraded by foraging and rooting behaviour of deer, pigs and cows; which can have serious consequences for general forest structure and regeneration. The loss of leaf litter due to these introduced species means large areas of bare soil exist within the Kagu’s range. Large areas of habitat have been lost to mining, and logging has aided access to Kagu by hunters and dogs. Deforestation and forest fragmentation does not currently appear to be a major threat to this species, as sufficient habitat is believed to remain. Disease could also pose a serious threat in the future, as outbreaks in the Rivière Bleue area are thought to have killed tens of birds during the 2006-2007 breeding season.
Conservation Underway
The Kagu is a national emblem for New Caledonia and the single greatest bird conservation priority for the region. It receives full legal protection through its listing on CITES Appendix 1. The largest subpopulations inhabit the Parc Provincial Rivière Bleue and Parc Provincial des Grandes Fougères; an actively managed protected area, which controls populations of dogs and cats and reintroduced a number of captive-bred Kagus in the 1980s and 90s. The second largest subpopulation inhabits the protected Reserve Speciale de Faune et de Flore de la Nodela, although there is no dog control or provision of wardens there. Legislation and education programmes are in place to reduce predation by hunting dogs. This is hard to control and occasional killings still occur. Captive breeding has been in progress since 1978 and reintroduction has helped boost wild Kagu numbers. In 2008, a group of 10 institutions drafted the Kagu Species Action Plan for the period of 2009-2020.
Conservation Proposed
Unknown areas of forest must be surveyed for the presence of Kagu. Populations in better-known ranges should continue to be monitored. Dispersal of individuals between isolated subpopulations needs to be studied to ensure gene flow and avoid inbreeding. Management of dogs at the Reserve Speciale de Faune et de Flore de la Nodelais must be introduced. A small mobile survey team should be employed to visit ‘Kagu listening points’ in specific forests. Such surveys would improve total population estimates and gauge the effectiveness of dog control measures. The effects of deer must be assessed, and the feasibility of controlling their populations at key sites investigated. The effects of rat predation at different sites must be determined, particularly in the north of the island. Conservation projects should be initiated in other areas where Kagu subpopulations are known to exist. Educational and public awareness of Kagu conservation and responsible dog ownership need to be intensified.
Links
References
BirdLife International (2013) Species factsheet: Rhynochetos jubatus. Downloaded from www.birdlife.org on 30/04/2013.

BirdLife International (2008). Rhynochetos jubatus. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.1. www.iucnredlist.org. Downloaded on 30/04/2013.

Ekstrom, J. M. M., Jones, J. P. G., Willis, J. and Isherwood I. (2000). The Humid Forests of New Caledonia: Biological Research and Conservation Recommendations for the Vertebrate Fauna of Grande Terre. Cambridge, U.K.: CSB Conservation Publications.

Ekstrom, J. M. M., Jones, J. P. G., Willis, J., Tobias, J., Dutson, G. and Barré, N. (2002). New Information on the Distribution, Status and Conservation of Terrestrial Bird Species in Grande Terre, New Caledonia. Emu. 102:197-207.

Gula, R., J. Theuerkauf, S. Rouys & A. Legault. 2010. An audio/video surveillance system for wildlife. European Journal of Wildlife Research 56: 803-807.

Hunt, G. R. (1992). Census of kagus (Rhynochetos jubatus) on the Main Island of New Caledonia During 1991 / 1992. Unpublished Report for Association pour la Sauvegarde de la Nature Neo-Caledonienne, Noumea.

Hunt, G. R. (1996). Environmental Variables Associated with Population Patterns of the Kagu Rhynochetos jubatus of New Caledonia. Ibis 138: 778-785.

Hunt, G. R. (1996). Family Rhynochetidae (Kagu). In del Hoyo, J., Elliott, A. and Sargatal, J. (editors): Handbook of the Birds of the World, Volume 3 (Hoatzin to Auks). Barcelona: Lynx Edicions. 218-225.

Hunt, G. R., Hay, R. and Veltman, C. J. (1996). Multiple Kagu Rhynochetos jubatus Deaths Caused by Dog Attacks at a High-Altitude Study Site on Pic Ningua, New Caledonia. Bird Conservation International 6: 295-306.

Letocart, Y. (1989). Etude sur la Biologie du Cagou Huppe dans Le Parc Territorial de la Rivière Bleue. Unpublished report to the Service de l’Environnement et de la Gestion des Parcs et Reserves de la Province Sud.

Letocart, Y. and Salas, M. (1997). Spatial Organisation and Breeding of Kagu Rhynochetos jubatus in Rivière Bleue Park, New Caledonia. Emu. 97. 97-107.

Sibley, C. G. and Ahlquist, J. (1990). Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale University Press, New Haven.

Stoeckle, B.C., J. Theuerkauf, S. Rouys, R. Gula, A. Lorenzo, C. Lambert, T. Kaeser & R. Kuehn. 2012. Identification of polymorphic microsatellite loci for the endangered Kagu (Rhynochetos jubatus) by high-throughput sequencing. Journal of Ornithology 153: 249-253.

Theuerkauf, J., S. Rouys, J.M. Mériot & R. Gula. 2009. Group territoriality as a form of cooperative breeding in the flightless Kagu of New Caledonia. Auk 126: 371-375.

Thiollay, J. M. (1989). Etude et Conservation du Cagu (Rhynochetos jubatus). Unpublished report to CNRS / SRETIE, Paris.
Acknowledgements
Text compiled by Michelle Harrison. Factchecked by Jorn Theuerkauf.

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