Scientific Name: Mystacina robusta
Species Authority
Intra-specific Authority: Dwyer, 1962
Common Name/s: English – New Zealand Greater Short-tailed Bat
Assessment Information [top]
Red List Category & Criteria: Critically Endangered D ver 3.1
Year Assessed: 2008
Assessor/s O'Donnell, C.
Evaluator/s: Lamoreux, J. (Global Mammal Assessment Team), Racey, P.A., Medellín, R. & Hutson, A.M. (Chiroptera Red List Authority)
Justification:
Listed as Critically Endangered (Possibly Extinct candidate) because there have been no confirmed reports of this species since it was last seen in 1967 on Big South Cape Island, New Zealand. Recent, unconfirmed reports of bats from this small island and a neighbouring island, however, could be this species and surveys are urgently needed. Should this species be found to persist, its population size would almost certainly be tiny (<50 mature individuals) as would its geographic range.
History: 1996 - Extinct (IUCN Conservation Monitoring Centre 1988)
1990 - Extinct (IUCN Conservation Monitoring Centre 1988)
1994 - Extinct (IUCN Conservation Monitoring Centre 1988)
Geographic Range [top]
Range Description: This species is endemic to New Zealand. There have been no confirmed sightings of the species since 1967 when it was found on Big South Cape Island (near Stewart Island). It might still persist here or on other small privately-owned islands near Stewart Island.
It is known from subfossil remains on both North Island and South Island. By the time of European arrival, c.200 years ago, the species was probably already restricted to small islands off the coast of Stewart Island.
Countries: Presence uncertain:
New Zealand
Population [top]
Population: It has not been recorded since 1967 and is possibly extinct.
Population Trend: Unknown
Habitat and Ecology [top]
Habitat and Ecology: Although the habitat preferences of this species are incompletely known, it is presumed to have similar requirements to Mystacina tuberculata in that it was a forest species that was largely restricted to undisturbed old-growth forest. Remains of this species in limestone caves suggest that it roosted in caves, and it is possible that the species also roosted in tree cavities, although there is no direct evidence for this (Lloyd 2001).
Systems: Terrestrial
Threats [top]
Major Threat(s): Evidence from owl middens indicates a marked decline in this species following the introduction of the Kiore or Pacific Rat (Rattus exulans) to New Zealand, and it seems probable that this introduction largely resulted in the demise of Mystacina robusta (Lloyd 2001).
Conservation Actions [top]
Conservation Actions: Rats have been eradicated from both Big South Cape (where the species was last seen) and neighbouring Putauhina Island. Following these eradications, there have been several reports of bat sightings from Putauhina, and in 1999 Colin O'Donnell recorded Mystacina-like echolocation calls from the island that do not belong to M. tuberculata (O'Donnell 1999). There have also been two unconfirmed reports of bats being seen on Big South Cape. The identity of the bats being seen still must be confirmed, and although M. tuberculata is thought to have once inhabited these islands, the nearest populations of it or the only other New Zealand bat species (Chalinolobus tuberculatus) are more than 50 km away. For this reason, there is a real possibility that M. robusta still survives in low numbers (C. O'Donnell pers. comm.).
Rats continue to be eradicated from all islands in this group, and more surveys for M. robusta are planned (C. O'Donnell pers. comm.).
www.redlist.org/details/14260
