Kagu pigs and dogs. New Caledonia lacked mammals (except for bats) before the arrival of humans, and many of its native species have been negatively affected by introduced mammals. Rats have a big impact on nestlings, accounting for 55% of nestling losses. Kagus also suffer from habitat loss caused by mining and forestry. Concern was first raised about the future of the kagu in 1904. The first concrete evidence of the impact of dogs came when a New Zealand researcher's study population was quickly exterminated by dogs in the 1990s, although suspicions about the importance of dogs and other predators had
Kagu gruiform, the kagu is generally considered related to the extinct adzebills from New Zealand and the sunbittern from Central and South America. Recent studies do indicate that the sunbittern is the closest living relative of the kagu. For example, Fain & Houde found these to be certainly sister taxa. They and the mesites did not group with traditional Gruiformes in their study, but instead with their proposed clade Metaves, which also includes the hoatzin, pigeons, Caprimulgiformes, flamingos, tropicbirds, Apodiformes, sandgrouse and grebes. The internal structure of this group was not well resolvable by their data, although later studies confirmed a