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.
Communication Channels: acoustic ; chemical
Perception Channels: visual ; tactile ; ultrasound ; echolocation ; chemical
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.
Mystacina robusta was listed as extinct by the IUCN Red List in 1990.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: critically endangered
There are no known adverse effects of Mystacina robusta on humans.
It is not known if or how humans benefited from Mystacina robusta.
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.
Ecosystem Impact: disperses seeds; pollinates
Commensal/Parasitic Species:
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.
Animal Foods: birds; insects; terrestrial non-insect arthropods; terrestrial worms
Plant Foods: fruit; nectar; pollen; flowers
Primary Diet: omnivore
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.
Biogeographic Regions: oceanic islands (Native )
Other Geographic Terms: island endemic
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.
Range elevation: 140 (low) m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: forest ; scrub forest
Other Habitat Features: caves
Information on lifespan/longevity for Mystacina robusta is not available.
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).
Range mass: 25 to 35 g.
Range length: 90 (low) mm.
Range wingspan: 290 to 310 mm.
Other Physical Features: endothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
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.
Known Predators:
Anti-predator Adaptations: cryptic
Mystacina robusta is thought to have been monogamous. Other information regarding their mating system is not known. To attract females, males of the related species, M. tuberculata, fly to hollow trees and call with a repetitive, high-intensity noise which can be heard by the human ear from a distance of 50 meters. Other details of the breeding of M. tuberculata are not known.
Mating System: monogamous
Little is known about the reproduction of this species. They were thought to breed once a year. The time of breeding is not known since this species of bat is thought to have gone extinct about 40 years ago. J.A. Mackintosh found a juvenile specimen on Solomon Island and also observed several nursery colonies with adolescents in hollow rata trees and in the burrows of sooty shearwaters from late April to mid May of 1963-65 (Lloyd, 2001). This suggests that M. robusta had one young per year, born around April-May. This is approximately four or five months later than the birth season of Mystacina tuberculata. The time of mating and details of the reproductive cycle are not known, although mating by M. tuberculata occurs sometime between February and April.
Breeding interval: Greater short-tailed bats bred once yearly.
Breeding season: This information is not known for Mystacina robusta, but its closest relative, Mystacina tuberculata breeds between February and April
Range number of offspring: 1 to 1.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
No information is available about the parental investment of Mystacina robusta. However, as in other bat species, females would have nursed and cared for their single offspring until they became independent.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female)
The New Zealand greater short-tailed bat (Mystacina robusta) is one of two species of New Zealand short-tailed bats, a family (Mystacinidae) unique to New Zealand. Larger than the New Zealand lesser short-tailed bat, there have been no confirmed sightings of this species since 1965[3] and it is considered to be critically endangered, if not extinct.[4] In prehistoric times it lived in the North and South Islands but by the time of European arrival was restricted to small islands near Stewart Island/Rakiura. A rat invasion of Taukihepa/Big South Cape Island in 1963 was thought to have led to the species' extinction,[5] however, recent surveys have raised hopes that the species may still exist.[6]
M. robusta was not considered to be separate from the New Zealand lesser short-tailed bat (Mystacina tuberculata) until 1962, when it was suggested as a subspecies.[7] It was not recognized as a completely separate species within Mystacinidae until 1985, long after it was thought to have become extinct.[8] Morphologically, M. robusta is larger than M. tuberculata with specimens of the former having a mean forearm length of 45.3-47.5mm as opposed to the latter, 40-45mm, which also has larger ears that reach beyond the muzzle when pushed forward.[7] It is described as having a wingspan of 300mm[9] and a body length of 90mm.[10]
Very little is known about the biology of the species, since it was not recognized as a separate species until after it is believed to have become extinct.[8] Edgar Stead visited Taukihepa/Big South Cape Island in 1936 and made several observations. He described the species as flying no more than “ten feet above the ground” and always after dusk.[11] At one point he found seven bats roosting in a tree cavity in a state of torpor. After capturing a few and putting them in a cage they crawled around on the floor,[11] much like New Zealand lesser short-tailed bats are known to do. As well as roosting in tree cavities, it is known that they roosted in granite caves on Taukihepa/Big South Cape Island and Rerewhakaupoko/Solomon Island.[5]
The few existing photos show that this species had dark-brown fur and darker wings.[5] Nothing is known about their natural diet; however, it is likely to be similar to the diet of the closely related lesser short-tailed bat, which eats insects, especially beetles, flies, and moths, as well as flowers, fruit, nectar, and pollen.[12] As a highly endangered member of an ancient evolutionary family, the species is accorded a high ranking on the EDGE list of mammals, sitting ninth.[10]
Sub-fossil evidence suggests that M. robusta was widespread throughout New Zealand until the arrival of the Polynesian rat/Kiore.[13][14] There are no records of this species from the North Island and South Island since the arrival of Europeans and it was probably restricted to several islands near Stewart island/Rakiura by this time.[13] The only records from the twentieth century are from caves on Taukihepa/Big South Cape Island and Rerewhakaupoko/Solomon Island.[15] Here it survived in the absence of rats until the 1960s.
The last refuge of this species was Taukihepa/Big South Cape Island until ship rats (Rattus rattus) were accidentally introduced in 1963. This rodent invasion decimated the bird life of the island, leading to the extinction of Stead's bush wren (Xenicus longipes variabilis) and South Island snipe (Coenocorypha iredalei). The South Island saddleback (Philesturnus carunculatus) was only saved by the translocation of 36 individuals to a nearby island.[5] M. robusta, not recognized as a separate species at the time, was not considered a priority for conservation effort and was believed to have subsequently become extinct, last seen in 1965.[3]
In the late 2000s, eyewitness reports of bats from Taukihepa/Big South Cape Island and nearby Putauhina Island spurred new searches for this species.[16] In 1999 an expedition to the islands recorded unusual "mystacinid-like" echolocation calls on Putauhina Island, but no bats were seen or caught on this or a subsequent expedition in 2009.[16] As a result of this evidence the IUCN status of the species, formerly listed as extinct, has been changed to 'critically endangered'[4] and the New Zealand threat classification is currently 'data deficient'.[16] Further searches are required to ascertain if the species still persists on these islands. Due to its imperiled status, it is identified by the Alliance for Zero Extinction as a species in danger of imminent extinction.[17] The bat is among the 25 "most wanted lost" species that are the focus of Global Wildlife Conservation's "Search for Lost Species" initiative.[18]
The New Zealand greater short-tailed bat (Mystacina robusta) is one of two species of New Zealand short-tailed bats, a family (Mystacinidae) unique to New Zealand. Larger than the New Zealand lesser short-tailed bat, there have been no confirmed sightings of this species since 1965 and it is considered to be critically endangered, if not extinct. In prehistoric times it lived in the North and South Islands but by the time of European arrival was restricted to small islands near Stewart Island/Rakiura. A rat invasion of Taukihepa/Big South Cape Island in 1963 was thought to have led to the species' extinction, however, recent surveys have raised hopes that the species may still exist.
