Short-tailed Bat Mystacina Tuberculata Research Articles

The conservation status of New Zealand bats, 2009

The New Zealand Threat Classification System (NZTCS) is a national system used to assess the risk of extinction faced by New Zealand plants, animals and fungi. The system is specifically designed to be relevant to New Zealand's unusual ecological and geographic conditions. We undertook a re-evaluation of the status of seven bat taxa based on our knowledge of New Zealand bats using revised NZTCS criteria. Five taxa were listed as Threatened or At Risk: one as Nationally Critical (long-tailed bat Chalinolobus tuberculatus ‘South Island’), one as Nationally Endangered (southern lesser short-tailed bat Mystacina tuberculata tuberculata), two as Nationally Vulnerable (long-tailed bat ‘North Island’ and northern lesser short-tailed bat M. t. aupourica) and one as Declining (central lesser short-tailed bat M. t. rhyacobia). One taxon was assessed as Data Deficient (greater short-tailed bat M. robusta) and one (little red flying fox Pteropus scapulatus) as Vagrant. We suspect declines result primarily from predation and competition from introduced mammals, habitat degradation, and disturbance.

Bats that walk: a new evolutionary hypothesis for the terrestrial behaviour of New Zealand's endemic mystacinids

BackgroundNew Zealand's lesser short-tailed bat Mystacina tuberculata is one of only two of c.1100 extant bat species to use a true walking gait when manoeuvring on the ground (the other being the American common vampire bat Desmodus rotundus). Mystacina tuberculata is also the last surviving member of Mystacinidae, the only mammalian family endemic to New Zealand (NZ) and a member of the Gondwanan bat superfamily Noctilionoidea. The capacity for true quadrupedal terrestrial locomotion in Mystacina is a secondarily derived condition, reflected in numerous skeletal and muscular specializations absent in other extant bats. The lack of ground-based predatory native NZ mammals has been assumed to have facilitated the evolution of terrestrial locomotion and the unique burrowing behaviour of Mystacina, just as flightlessness has arisen independently many times in island birds. New postcranial remains of an early Miocene mystacinid from continental Australia, Icarops aenae, offer an opportunity to test this hypothesis.ResultsSeveral distinctive derived features of the distal humerus are shared by the extant Mystacina tuberculata and the early Miocene Australian mystacinid Icarops aenae. Study of the myology of M. tuberculata indicates that these features are functionally correlated with terrestrial locomotion in this bat. Their presence in I. aenae suggests that this extinct mystacinid was also adapted for terrestrial locomotion, despite the existence of numerous ground-based mammalian predators in Australia during the early Miocene. Thus, it appears that mystacinids were already terrestrially-adapted prior to their isolation in NZ. In combination with recent molecular divergence dates, the new postcranial material of I. aenae constrains the timing of the evolution of terrestrial locomotion in mystacinids to between 51 and 26 million years ago (Ma).ConclusionContrary to existing hypotheses, our data suggest that bats are not overwhelmingly absent from the ground because of competition from, or predation by, other mammals. Rather, selective advantage appears to be the primary evolutionary driving force behind habitual terrestriality in the rare bats that walk. Unlike for birds, there is currently no evidence that any bat has evolved a reduced capacity for flight as a result of isolation on islands.

Nuclear gene sequences confirm an ancient link between New Zealand’s short-tailed bat and South American noctilionoid bats

Molecular and morphological hypotheses disagree on the phylogenetic position of New Zealand’s short-tailed bat Mystacina tuberculata. Most morphological analyses place Mystacina in the superfamily Vespertilionoidea, whereas molecular studies unite Mystacina with the Neotropical noctilionoids and imply a shared Gondwanan history. To date, competing hypotheses for the placement of Mystacina have not been addressed with a large concatenation of nuclear protein sequences. We investigated this problem using 7.1 kb of nuclear sequence data that included segments from five nuclear protein-coding genes for representatives of 14 bat families and six laurasiatherian outgroups. We employed the Thorne/Kishino method of molecular dating, allowing for simultaneous constraints from the fossil record and varying rates of molecular evolution on different branches on the phylogenetic tree, to estimate basal divergence times within key chiropteran clades. Maximum likelihood, minimum evolution, maximum parsimony, and Bayesian posterior probabilities all provide robust support for the association of Mystacina with the South American noctilionoids. The basal divergence within Chiroptera was estimated at 67 mya and the mystacinid/noctilionoid split was calculated at 47 mya. Although the mystacinid lineage is too young to have originated in New Zealand before it split from the other Gondwanan landmasses (80 mya), the exact geographic origin of these lineages is still uncertain and will not be answered until more fossils are found. It is most probable that Mystacina dispersed from Australia to New Zealand while other noctilionoid bats either remained in or dispersed to South America.

Diet and nectarivorous foraging behaviour of the short-tailed bat (Mystacina tuberculata)

There are two microchiropteran bat species in New Zealand: the long-tailed bat Chalinolobus tuberculatus and the short-tailed bat Mystacina tuberculata. Both species coexist on Little Barrier Island in the Hauraki Gulf, New Zealand. In this study we examined the diet of M. tuberculata, and the activity levels of both bat species associated with Metrosideros excelsa, a native flowering plant and potential nectar source, on Little Barrier Island. Between November 1994 and February 1996, M. tuberculata were caught in mist-nets, and their faecal pellets were collected for later dietary analysis. In addition, pollen samples were collected from the fur of bats caught during December 1995 and January 1996. Faecal analysis showed that M. tuberculata on Little Barrier Island exhibits a high degree of omnivory, with its diet comprising flying and non-flying arthropods, and also pollen and other plant material. During December 1995 and January 1996, the activity levels of both bat species associated with flowering and non-flowering M. excelsa trees were investigated by recording bat echolocation calls with automatic detecting and recording units. Significantly higher numbers of M. tuberculata echolocation calls were recorded near flowering M. excelsa trees than near non-flowering ones, whereas the numbers of C. tuberculatus calls did not differ significantly between flowering and non-flowering trees. These results contribute further to the existing evidence for nectarivory in M. tuberculata.

A new laelapine genus and species (Acari: Laelapidae) from the short-tailed batMystacina tuberculata, in New Zealand

Abstract Chirolaelaps mystacinae n. gen., n.sp. is described from the short-tailed bat, Mystacina tuberculata Gray, 1843 (Chiroptera: Mystacinidae) of New Zealand.