Polynesian Megapode (Megapodius pritchardii)
Justification This species qualifies as Critical because it has a viable population on just one tiny island (which is an active volcano) and is likely to be declining, despite available habitat, owing to harvesting and predation. It has been translocated to two further islands but further evidence is needed to confirm that these populations are self-sustaining.
Identification 38 cm. Medium-sized, brown-and-grey megapode. Mostly brownish-grey, paler on head and neck, browner on back and wings, with short, rounded crest on nape. Feathers of face and throat sparse, allowing red skin to show through. Yellow bill. Yellow to light red legs and feet.
Similar spp. Buff-banded Rail Gallirallus philippensis has bold bars and much longer bill. Immature Purple Swamphen Porphyrio porphyrio larger with white undertail-coverts. Feral chickens have prominent tails. Spotless Crake Porzana tabuensis smaller and darker with red eyes and legs. Voice Three-part whistle kway-kwee-krrrr, usually a duet with male giving first two notes, female the third note.
Population Estimate: 376 - 470
Population trend: decreasing (continuing)
Range estimate: 70 km²
Country Endemic: Yes
Range & Population Megapodius pritchardii is endemic to Niuafo'ou, Tonga, and has been introduced to Late and Fonualei (where its status is uncertain). On Niuafo'ou, it is concentrated around the inner slopes of the caldera and on two cat-free islets in the crater lake. In 1979, the population was estimated at 820 adults and, in 1991-1993, at 188-235 pairs occupying 641 ha of 719 ha of suitable habitat. This represents 52-65% of possible carrying capacity, assuming an average of 0.5 pairs per ha. A comparison between the two population figures is not appropriate because of differences in techniques, but comparisons between individual sites and interviews with local people strongly suggest an overall decline.
Ecology It inhabits broadleaved forest ranging from secondary to mature, but needs open ground with little vegetation, where it can forage in leaf-litter and top soil mainly for insects and worms, but also small reptiles, seeds and small fruit. 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.
Threats All nesting sites are harvested and at least 50% of all eggs laid are collected or destroyed. Adults are also hunted on a small scale, and adults and chicks are predated by feral cats and dogs, while pigs may compete for food.
Action 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, and an additional 35 eggs and chicks were transferred to Fonualei, both uninhabited and rarely visited by humans. Surveys in 1995, 1996 and 1997 showed that breeding was successful on both islands, although there is no evidence that chicks have survived.
Targets *On Niuafo'ou, continue long-term monitoring of the nesting-grounds. *Protect the three crater-lake islets as nature reserves, minimise disturbance and regularly survey for introduced predators. *Enforce the ban on egg-collecting or restrict egg-collecting, preferably through a council of residents endowed with necessary powers. *On Late, establish a long-term monitoring programme and continue translocation following strict guidelines. *Investigate the possibility of translocation to Tofua. *Continue and intensify the conservation awareness programme.
Reproduced on BirdForum with kind permission from http://www.birdlife.org.uk
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