Justification of Red List Category
This charismatic species is classified as Endangered on the basis of its very small, severely fragmented population, with a very small extent of occurrence limited to New Caledonia, which is suffering an overall decline. However, there is cause for hope, as recent research shows it still to be widespread, and populations in some areas are increasing due to a reduction in incidental killing by hunting dogs. Should the species's range be found not be declining this species will warrant downlisting to a lower category of threat.
There are an estimated >250 mature individuals and >1000 total individuals in Parc des Grandes Fougères (Jörn Theuerkauf in litt. 2016), 500 birds in Parc Provincial Rivière Bleue (J.-M. Mériot in litt. 2007, Theuerkauf in litt. 2016) and at least 491 mature individuals elsewhere.
Thanks to new field studies (Chartendrault and Barré 2005, 2006) and oral information, it appears that kagus are still present in most of the areas surveyed by Hunt in 1992. Chartendrault and Barré found that kagus were present on 36 of 82 surveyed massifs (44%) between 2003 and 2006, and populations seem to be stable or even increasing in the southern province, although they may be declining or stable in the North. In the Mont Do and Nakada area (Entre les monts Do et Nakada IBA), Hunt found 135 birds over 14 point counts. Chartendrault found 113 birds in the same area (different points) in 2005 over only 7 points (Chartendrault and Barré 2005, 2006). Rats and cats may affect the population, although there are currently no proven records of this. Hunting dogs are the main threat to the species, which particularly affect populations in unprotected areas outside of Riviere Bleue. However, hunting activity (particularly with dogs) is decreasing in some areas, allowing birds to recolonize (R. Gula and J. Theuerkauf in litt. 2012).
Rhynochetos jubatus is endemic to New Caledonia (to France). The highest recorded numbers and densities are in Parc des Grandes Fougères, with over 250 mature individuals and over 1000 individuals in total, an estimate based on seven families followed by radiotracking (Jörn Theuerkauf in litt. 2016). Before 2010 the highest densities were in Parc Provincial Rivière Bleue (Theuerkauf in litt. 2016), where numbers had increased and was estimated at 300 in 1998, and 500 birds in 2007 (Y. Létocart and C. Lambert in litt. 1999, Ekstrom et al. 2000, Ekstrom et al. 2002, Mériot in litt. 2007). Parc des Grandes Fougères and Parc Provincial Rivière Bleue are the only locations in which long term data are available (Theuerkauf in litt. 2016). Breeding surveys in Parc des Grandes Fougères suggest increasing numbers, whilst surveys between 2002-2012 in Parc Provincial Rivière Bleue show fluctuating numbers, but a stable trend over the long term (Theuerkauf in litt. 2016). At least 15% of the individuals surveyed however died in the Rivière Bleue Park during the 2006 breeding season, perhaps due to disease, highlighting the fragility of this group of animals (J. Theuerkauf in litt. 2007). Elsewhere, a survey of calling birds in 1991-1992 recorded 491 adults, 82% in Province Sud, and another survey conducted between 2003 and 2006 (though not designed specifically for Kagu survey) recorded 357 birds, but these figures may have been underestimates (Hunt 1996, Y. Létocart and C. Lambert in litt. 1999, Mériot in litt. 2007). The population therefore is likely to be in excess of 850 birds. It was previously thought to be declining outside Rivière Bleue, with most subpopulations thought to be small and some subpopulations considered to have become extinct (Hunt 1996, Ekstrom et al. 2000, Ekstrom et al. 2002). It is thought groups outside of the two studied reserves are stable, though data is lacking to support this (Theuerkauf in litt. 2016).
It inhabits a variety of forest-types, usually in humid forest with open understory, at mid-altitudes but ranges from sea-level to 1,400 m and also occupies drier forests at low altitude in the centre of the island (Boulouparis-La Foa area, from 100 m in the upper Ouenghi river) (Chartendrault and Barré 2005, 2006) and sometimes utilises closed-canopy scrub during the wet season (Hunt 1996, Létocart and Salas 1997). It feeds on earthworms, insects, snails and lizards (Létocart 1991). Territories of neighboring families can overlap, sometimes quite substantially (Gula in litt. 2016), though pairs studied in Rivière Bleue occupied exclusive territories of 10-28 ha (Létocart and Salas 1997). Reproductive output in Rivière Bleue was 0.4 fledglings per family per year in 2002-2012 and 1.4 fledglings per year per family in 2011-2016 in Parc des Grandes Fougeres (Theuerkauf et al. submitted]). Birds survive over 30 years in captivity (Y. Létocart and C. Lambert in litt. 1999), and at least 22 years in the wild (results from several radiotracked Kagus in the wild [R. Gula and J. Theuerkauf in litt. 2012]). A recent study showed that Kagus are able to withstand much higher heavy metal concentrations than other birds worldwide (Theuerkauf et al. 2015).
Dogs killed 17 out of 21 birds with radio-transmitters at Pic Ningua in 1993 (Hunt et al. 1996). Most mortality at Rivière Bleue occurs in chicks under three weeks old, possibly by introduced rats and cats (Y. Létocart in litt. 1999), although a long term study showed that rats had no impact on Kagu populations there (Gula et al. 2010). Feral pigs occasionally take eggs (two out of 40 eggs and unlikely to be a significant threat [J. Theuerkauf in litt. 2007, S. Rouys in litt. 2008]) and forest floor rootings may make foraging for worms less easy (Hunt 1997, Létocart and Salas 1997, DDRP 1998, Y. Létocart in litt. 1999, Ekstrom et al. 2000). Introduced Rusa deer Cervus timorensis are damaging forests in the Boulouparis - La Foa - Canala triangle, an important areas for the species outside Rivière Bleue, and so may pose a threat to the species (Chartendrault and Barré 2005, 2006). Forest is being slowly eroded by mining and fires (Y. Létocart and C. Lambert in litt. 1999, Ekstrom et al. 2000, J. Ekstrom in litt. 2003), and logging aids access for hunters and dogs (Y. Létocart in litt. 1999, Ekstrom et al. 2000). Disease in the Rivière Bleue may be a severe threat in the future (Chartendrault and Barré 2005, 2006).
Conservation Actions Underway
CITES Appendix I. Dogs are controlled in Rivière Bleue (Létocart 1991, Hunt et al. 1996). A population is protected in Reserve Speciale de Faune et de Flore de la Nodela, but without wardening or dog control (Ekstrom et al. 2000). Legislation and education aims to reduce capture by hunting dogs, but incidental killings are difficult to control (Hunt et al. 1996). Birds have been successfully bred in captivity since 1978, and reintroduced to protected areas (Bregulla 1987). A Kagu Species Action Plan (PASC) which spans the period 2009-2020 was compiled in 2008. A pilot study on the behavior of wandering dog tribes was initiated in 2013 in Massif des Lèvres - an IBA in danger and the northern most refuge of the Kagu known to date.
55cm. Ghostly-grey bird, belonging to a monospecific family. Flightless. Uniform plumage contrasts with orange-red bill and legs. Long shaggy crest erected in display. Spread wings expose prominent black-and-white barring. Similar spp. Unmistakable; heron species are rarely found in forest and none has uniform grey plumage or red bare parts. Voice Loud barking at dawn and various quiet hissing and rattling calls. Hints Usually seen stationary or walking slowly in shaded forest. Locally common in Rivière Bleue: permits and advice can be obtained at the entrance gate.
Text account compilers
Benstead, P., Derhé, M., Dutson, G., Ekstrom, J., Mahood, S. & Stattersfield, A.
Chartendrault, V., Ekstrom, J., Lambert, C., Létocart, Y., Mériot, J., Rouys, S., Theuerkauf, J. & Gula, R.
BirdLife International (2019) Species factsheet: Rhynochetos jubatus. Downloaded from http://www.birdlife.org on 22/10/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/10/2019.