Justification of Red List Category
This species was known from the Chatham Islands, New Zealand, but became Extinct between 1893 and 1895. It is thought that invasive species are responsible, both through direct predation and habitat modification.
Cabalus modestus was endemic to Chatham, Mangere and Pitt Islands, New Zealand. It was first discovered on Mangere in 1871, and 26 specimens collected there are known from museum collections. It became extinct on the island between 1893 and 1895 (Tennyson and Martinson 2006). The species is also known from 19th century bones from Chatham and Pitt Islands.
It is likely to have occurred in scrubland and tussock grass.
Its extinction was presumably caused by predation by rats and cats (which were introduced in the 1890s), habitat destruction to provide sheep pasture (which destroyed all of the island's bush and tussock grass by 1900), and from grazing by goats and rabbits (Marchant and Higgins 1993). On Chatham and Pitt Islands Olson (1975c) has suggested that its extinction resulted from competition with the larger Dieffenbach's Rail Gallirallus dieffenbachii (also extinct), but the two species have been shown to have been sympatric on Mangere (Tennyson and Millener 1994).
Text account compilers
Brooks, T., Khwaja, N., Mahood, S., Martin, R
BirdLife International (2019) Species factsheet: Cabalus modestus. Downloaded from http://www.birdlife.org on 20/05/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/05/2019.