It inhabits broadleaved forest ranging from secondary to mature (Göth and Vogel 1995), but needs areas with little ground cover where it can forage in leaf-litter and top soil; mainly for insects and worms, but also small reptiles, seeds and small fruit (Rinke et al. 1993). It uses hot volcanic ash to incubate its eggs, a habit which confines its nesting sites to areas of loose soil close to vents, either in forest or in open ash, or beaches of crater lakes (Todd 1983).

Megapodius pritchardii is endemic to Tonga where although fossil evidence indicates it was once widespread, there is now only a remnant population on the island of Niuafo'ou and a re-introduced population on Fonualei. On Niuafo'ou it is concentrated around the inner slopes of the caldera (a large sunken water- and forest-filled crater formed after volcanic activity) and on two cat-free islets in the crater lake.

In 1979, the population was estimated at 820 adults (Todd 1983) and, in 1991-1993, at 188-235 pairs occupying 641 ha of 719 ha of suitable habitat (Göth and Vogel 1995). This represents 52-65% of possible carrying capacity, assuming an average of 0.5 pairs per ha (Göth and Vogel 1995). Comparisons between individual sites and interviews with local people had strongly suggested an overall decline (Göth and Vogel 1995). 

From 1991 to 1993, 60 eggs were buried at volcanically heated sites on Late (Göth and Vogel 1995), and an additional 35 eggs and chicks were transferred to Fonualei (Rinke 1994), both uninhabited and rarely visited by humans. A 2003 survey on Fonualei found the species to be common, comprising an estimated 300-500 adult individuals (Watling 2004), but there is no evidence of its continued existence on Late (MEECCDMMIC 2014, R. W. R. J. Dekker in litt. 2003, R. Dekker in litt. 2004). By 2013, the population on Fonualei had risen to an estimated 600-1,000 birds, assuming that all apparently suitable habitat was occupied (Butler 2013).

A survey in September 2010 revealed that the population on Niuafo'ou had undergone a dramatic decline in the number of nests at all known nesting grounds, and is now confined to small areas within the caldera. Historically, 27 nests were known from 13 different sites across Niuafo'ou (Goeth unpublished data, in Tilmouth 2010), but during the September 2010 survey only 10 active nests at 7 sites were found (Lloyd et al. 2011). The 2010 survey also failed to uncover any new nesting grounds since the research of Göth and Vogel (1995, 1997). 

As a result of the population increase on Fonualei, the population may be tentatively assumed to now be increasing overall despite the ongoing decline on Niuafo’ou (G. Dutson in litt. 2016).

Conservation Actions Underway 

It is legally protected, although in practice there is no enforcement. From 1991 to 1993, 60 eggs were buried at volcanically heated sites on Late (Göth and Vogel 1995), and an additional 35 eggs and chicks were transferred to Fonualei (Rinke 1994), both uninhabited and rarely visited by humans. Breeding was successful on Fonualei and the population appears to be established (R. W. R. J. Dekker in litt. 2003, C. Matevalea verbally 1999, Watling 2004), but surveys suggest the translocation failed on Late (R. Dekker in litt. 2004, A. Göth in litt. 2004). A Conservation Strategy for the species was published in 2011 by the World Pheasant Association and the Tonga Community Development Trust (Lloyd et al. 2011), and an Action Plan produced in 2014 (MEECCDDMMIC 2014).

Conservation Actions Proposed 

The Action Plan (MEECCDMMIC) includes proposals to: establish a sustainable egg harvesting regime on Niuafo’ou that enables the preservation of local culture and the future survival of the species; establish and implement a monitoring programme to periodically assess the population on Niuafo’ou; provide the scientific knowledge required to support the population recovery and conservation of the species on Niuafo’ou; establish an appropriate legislative and policy context for megapode conservation; take steps to prevent invasive species that would threaten megapodes from reaching Fonualei; carry out periodic monitoring to check the status of the megapode population on Fonualei; develop a plan for a transfer to Late Island once the planned programme to eradicate Polynesian rats has been successful; investigate the feasibility of establishing a population on Tofua Island; increase community support for the conservation of the megapode on Niuafo’ou; develop educational resources; and establish a national repository for information on the Polynesian Megapode.