The species 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). It has a cooperative, polyandrous breeding system; breeding clans consist of related males and unrelated females, with offspring remaining in the clan for up to ten years (Theuerkauf et al. 2009, 2018). It has a sex ratio bias of 42% (+/-12%) female hatchlings and 37% (+/-13%) female breeding individuals (Theuerkauf et al. 2018). Territories of neighbouring families can overlap, sometimes quite substantially (R. Gula in litt. 2016). 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]). The species breeds year-round, with eggs laid in every month except January and February (Barré et al. 2013). A recent study showed that Kagus are able to withstand much higher heavy metal concentrations than other birds worldwide (Theuerkauf et al. 2015).

Rhynochetos jubatus is endemic to New Caledonia (to France), with subpopulations occurring in Parc des Grandes Fougère and Parc Provincial Rivière Bleue; a small number of individuals occur elsewhere on the island (Hunt 1996, Ekstrom et al. 2000, 2002). The largest recorded subpopulation is in Parc des Grandes Fougères, where surveys have shown an increasing population size, estimated at over 1000 individuals in 2016 (J. Theuerkauf in litt. 2016). However, in 2017, two dogs killed half of all radio-tagged individuals over two months, resulting in over 75% of Kagu families in the park being destroyed (J. Theuerkauf in litt. 2018). In Parc Provincial Rivière Bleue, the population was estimated at 500 birds in 2007, with fluctuating numbers, but a stable trend over the long term (J. Theuerkauf in litt. 2016). However, surveys between 2002 and 2012 observed a population reduction at a rate equivalent to 20% every four years as a result of predation by dogs (J. Theuerkauf in litt. 2018). Elsewhere, a survey of calling birds in 1991-1992 recorded 491 adults, 82% in Province Sud, and another survey conducted in 2003-2006 recorded 357 birds, but these figures may have been underestimates (Hunt 1996, Y. Létocart and C. Lambert in litt. 1999, J.-M. Mériot in litt. 2007). Field surveys by Chartendrault and Barré (2005, 2006) confirmed that kagus were still found in most of the areas previously surveyed by Hunt in 1992 (Hunt 1996, R. Gula and J. Theuerkauf in litt. 2012). Trends outside Parc des Grandes Fougère and Parc Provincial Rivière Bleue are not known, but it is suspected that predation by dogs may also be causing declines elsewhere (J. Theuerkauf in litt. 2018).

Conservation Actions Underway

CITES Appendix I. A Kagu Species Action Plan (PASC) which spans the period 2009-2020 was compiled in 2008 (SCO 2008). It occurs in Parc des Grandes Fougère and Parc Provincial Rivière Bleue. 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). Dogs are controlled in Rivière Bleue (Létocart 1991, Hunt et al. 1996). 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). The population in Parc des Grandes Fougères has been monitored since 2011 (J. Theuerkauf in litt. 2016). A pilot study on the behaviour of wandering dog tribes was initiated in 2013 in Massif des Lèvres (L'Oiseau 2014).

Conservation Actions Proposed

Monitor the population size, trends and distribution. Survey poorly-known forest areas. Assess the genetic status of the population. Evaluate fragmentation and gene flow between subpopulations with molecular methods (Stoeckle et al. 2012). Investigate dispersal between isolated populations. Determine effects of rat predation at different sites, particularly in the north. Ascertain effects of deer. Investigate possibilities of deer population control in some important areas. Control dogs and cats in key forest sites. Conserve and manage key sites including Parc des Grandes Fougère and Parc Provincial Rivière Bleue. Maintain and restore connections between sites where the species occurs (SCO 2008). Increase public awareness programmes regarding Kagu conservation and responsible dog ownership. Consider reintroducing the species at Panié mountain (SCO 2008).