Mystacina robusta
New Zealand greater short-tailed bat

Until 1965, Mystacina robusta was only known to have existed on Big South Cape and Solomon Islands in New Zealand. Subfossils in swamps and caves in the North and South Islands suggest its range was much larger several hundred years ago (King, 1990). Several hundred bats of this species occupied a cave at Puwai on Big South Cape Island until 1964-65. A couple of larger caves on Solomon Island were occupied until the 1950's. (Dowding and Murphy, 1994)

Big South Cape Island, adjacent to Solomon Island, rises to 240 m. The shorelines of both islands are rugged and contain numerous caves. The largest of these caves is at Puwai on the south coast of Big South Cape. This cave was occupied by both species of Mystacina until 1965 (Daniel and Baker, 1986). Individuals were also known to roost in seabird burrows. Mystacina robusta individuals probably foraged in moist forest and muttonbird scrub (Olearia) habitats, as do their smaller relatives, M. tuberculata. (Daniel and Baker, 1986)

Mystacina robusta was a medium-sized and extremely robust bat species. Average size is about one-third larger than their congener, lesser short-tailed bats Mystacina tuberculata. Individuals had stocky bodies with prominent, pointed ears and nostrils and a set of short whiskers. The short tail penetrated the tail membrane on its dorsal surface. The hind legs and feet were very robust, positioned under the body for quadrupedal locomotion on the ground. The fur was dark brown. Mystacina robusta was about 90 mm in total length, with a wingspan of about 290-310 mm. The tail measured approximately 15 mm and the species was estimated to weigh 25-35 g (King, 1990). (King, 1990)

Information on lifespan/longevity for Mystacina robusta is not available.

Greater short-tailed bats emerged from their roosts about 1-2 hours after sunset. They did not fly very fast, and did not manuever as rapidly as little pied bats, and generally they flew within 2-3 m of the ground. It has been suggested that this species of bat did not fly higher because of the thousands of petrels and shearwaters that were flying to their burrows during the breeding season. A close relative, Mystacina tuberculata also flies close to the ground; slow flight therefore appears to be characteristic of the genus Mystacina (Daniel and Baker, 1986). (Daniel and Baker, 1986)

Home Range

Not much is known about the home range of Mystacina robusta, but its close relative, Mystacina tuberculata, does not venture much further than 500 m from its roosting site (Daniel and Baker, 1986). (Daniel and Baker, 1986)

Mystacina robusta is thought to have gone extinct around 40 years ago. Therefore, no information is known about how it communicated with other bats, or which senses were especially developed. Vision is well developed in the close relative Mystacina tuberculata in order to see the flowers they sometimes feed on. This species also emits a repetitive, high-frequency call that can be heard by the human ear from a distance of up to 50 meters. The hearing of M. tuberculata is also well developed for echolocation in order to locate prey. It is not known how either species of Mystacina communicates with potential mates. (Dowding and Murphy, 1994)

It is not known what exactly the greater short-tailed bat ate. It is believed to have eaten the same wide range of food as its close relative Mystacina tuberculata. These foods include ground and tree-trunk arthropods, fruit, nectar, and pollen. An analysis done on the stomach contents of two greater short-tailed bats revealed the presence of both rata pollen and fern spores (King, 1990). Both species of short-tailed bats were partly carnivorous and ate fat and meat plucked off muttonbirds from time to time. It is also possible that M. robusta ate nestling birds. (Daniel and Baker, 1986; Lloyd, 2001)

In previous times, some Mystacina robusta may have been killed by laughing owls in the North and South Islands. Rattus exulans is believed to have either caused or assisted the extinction of the greater short-tailed bat in the North and South Islands, as well as Stewart Island. The final extinction of M. robusta is believed to have been caused by ship rats in 1962 and 1963 when they were introduced accidentally on Big South Cape and Solomon Islands (Dowding and Murphy, 19990. (Dowding and Murphy, 1994; Lloyd, 2001)

Mystacina robusta does not play any role in the ecosystem of New Zealand because this species is thought to have been extinct for over 40 years. At one time, M. robusta probably played a role as an insectivore, a pollinator of flowers, and a disperser of seeds.

There are no known adverse effects of Mystacina robusta on humans.

It is not known if or how humans benefited from Mystacina robusta.

It is not known if the effects of ship rats on these bats was the result of predation, competition for food, or continual disturbance of roosting sites. Ship rats readily prey on bats in other areas. Several hundred Mystacina were reported in Puai Cave on Big South Cape, and regular sightings of flying bats were made on both islands as well. In August 1964, the last confirmed M. robusta was collected from Big South Cape. By 1965, there were very few bats at all. J.A. Mackintosh mist-netted the last confirmed M. robusta in 1965 on Solomon Island (Dowding and Murphy, 1999). By 1966, there were no bats on either island. (Dowding and Murphy, 1994)

Mystacina robusta was listed as extinct by the IUCN Red List in 1990. (Dowding and Murphy, 1994)