New Zealand Lesser Short-tailed Bat

Lesser Short-tailed Bat
Conservation status
Vulnerable (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Chiroptera
Family:	Mystacinidae Dobson, 1875
Genus:	Mystacina Gray in Dieffenbach, 1843
Species:	M. tuberculata
Binomial name
Mystacina tuberculata
Subspecies
M. t. tuberculata M. t. aupourica M. t. rhyacobia

The Lesser Short-tailed Bat, Mystacina tuberculata or Pekapeka-tou-poto in Māori, is one of only two species of short-tailed bats in the family Mystacinidae, which is endemic to New Zealand.

Description

The New Zealand lesser short-tailed bat has a 60-70 mm long bat with an additional uropatagium that is around 20 mm long. It has a wingspan of 280-300 mm and a tail that is up to 12 mm.^[1] It weighs 10-22 g before foraging and its body weight can increase by 20-30% when it forages.^[1] The short-tailed bat has a thick and velvety pelage that is grayish to dark brown dorsally and paler vertically.^[2] The ears, wings, nose, legs and tail are not covered in fur and gray-brown skinned.^[1] The wing membranes of the bat have well-defined proximal region that are thick and striated. The curve of its toes have small basal talons inside and the thumbs have claws.^[2] Its nostrils are large and are longer than they are wide. The bat has a conical muzzle that is obliquely truncated and fairly long with whiskers around the mouth and nostrils.^[3] The feet are stout and board with soles covered in loose wrinkled skin.^[2] The New Zealand short-tailed bat is notable for its terrestrial locomotion. It uses its wrists and hind limbs to move on the ground quadrupedally.^[2] The bat moves in a symmetrical lateral-sequence walk with no aerial phase. The robust pelvic girdle, hind limbs and feet; a acteabulum that allows a wide range of movements and the basal talons may help the bat crawl and climb.^[3] The tongue is around 12 mm long and ridged with a tip covered in hairlike papillae, adaptations for foraging for nectar.^[4]

Range and ecology

As its name suggests, the New Zealand short-tailed bat is native only to New Zealand. In the North Island, there is one population in the Omahuta-Puketi Forest of the northern part of the island, seven large populations in the central part and a small population in the Tararusa Ranges of the southern end of the island.^[1] In the South Island, there are isolated populations in the Oparara Basin of northwestern Nelson, Eglinton Valley of Fiordland^[5] and Dart Valley of Aspiring National Park. There have been calls of this species recorded at Puakaiki on the west coast and there may be more populations in unsurveyed South Island forests.^[6] This species lives in elevations from sea level to 1,100 m, which is the highest altitudinal limit for New Zealand forests.^[7] The range of the short-tailed bat correlates with indigenous forests.^[6][7] Bats usually roost and forage in the forest interiors. They will move fly over open grassland to their foraging areas.

The short-tailed bat consumes and variety of food items and this foraging strategy is flexible. The bat eats small invertebrates like insects as well as flower fragments, fruit, nectar, pollen and wood.^[8] This species can adapt its diet to what food is abundant. When there is prolific fruiting, the bats will mostly feed on the fruit of perching lily.^[1] It is also possible that the bats feed on fern and fungal spores as they have been found in the fur.^[1] An individual bat can consume almost 50% of its body weight in a day.^[9] Short-tailed bats eat various fruits including the succulent bracts of kiekie, berries of perching lilies and fleshy exocarp and mesocarp of hinau fruits.^[9] The bat also pollinates perching lilies as well as pohutukawa, rata and rewarewa.^[1] The short-tailed bat is a major pollinatior of New Zealand’s only native, fully parasitic angiosperm Dactylanthus taylorii which is the only known ground flowering bat to be pollinated by a bat.^[10] In general, around 50% or more of its diet is made of insects like beetles, flies, moths and weta. When foraging for arthropods, short-tailed bats employ a number of tactics including aerial pursuit, gleaning off vegetation and the ground and digging though leaf litter.^[2]

Life history

New Zealand lesser short-tailed bays use mostly trees as roosts. They may roost communally or solitarily.^[2] Solitary bats may undergo daily torpor to conserve enery when it is cold.^[1] Mating in the short-tailed bat takes place during summer and autumn. During the mating season, male establish small territories or leks which they use as "singing posts" to attract females. Leks are established in trees near colonial roosts or commuting paths.^[1] Male singing begins spring and early summer. They make their calls during nighttime for periods of 10-40 minutes at a time. These calls can be heard by the human ear. They have an ultrasonic component and are repetitive.^[1] Males call even in rain and heavy winds.^[2] Females will visit groups of calling males, fly 8-10 km to find them.^[11] A male will defend this territory from other males and use it in subsequent years.^[2] Courtship peaks in late summer and autumn. After mating, a male will leave a vaginal plug in the female.^[1] The following winter, there is a delay in fertilization, implantation or development.^[1] Gestation may continue in the flowing spring and the females gives birth to a single young in summer.^[2] Females give birth outside a maternity roost. Young are born hairless and wrinkled, with the eyes closed and weighing around 5 g.^[9][1] However, the hind feet, legs and claws are well-developed. Apparently, the umbilical cord and placenta remain attached for three days. After one day, a young is active and grooming. ^[9] For the first five days, the ears are stuck to the sides of the head. Mothers remain with young in the maternity roost for the two weeks. Soon, the female moves to a communal roost and visits the maternity roost only to feed young.^[1] Milk teeth are replaced by permanent teeth after three weeks which is also when the young begins excising its wings. The young is capable of flight and is fully furred after four weeks.^[1] By six weeks, the young lives the maternity roost and by eight to twelve weeks it is fully grown skeletally.^[1] Its skeletal structure develops faster than its mass.^[2]

Conservation status

The New Zealand lesser short-tailed bat is listed by the IUCN as Vulnerable by the IUCN.^[12]It is potentially threatened by habitat loss, invasive species and animal control poisons. Both forest clearance and selective logging have reduced its habitat^[13] and the bat requires large areas of unmodified forest.^[1] While poisoning by 1080 poison, ingested from prey that contain it, can be a threat it does not appear to be a source of major mortality.^[14] The lesser short-tailed bat is legally protected under the Wildlife Act 1953. In 1995, a recovery plan was approved and the government has established a national bat database.^[12]

References

1. ^ ^{a b c d e f g h i j k l m n o p q} Lloyd, B. D. (2001) "Advances in New Zealand mammalogy 1990– 2000: short-tailed bats". Journal of the Royal Society of New Zealand 31:59–81.
2. ^ ^{a b c d e f g h i j} Gerald G. Carter and Daniel K. Riskin (2006) "Mystacina tuberculata" Mammalian Species 790 :1-8.
3. ^ ^{a b} Dwyer, P. D. (1962) Studies on the two New Zealand bats. Zoology Publications from Victoria University of Wellington 28:1–28.
4. ^ Daniel, M. J. (1976) "Feeding by the short-tailed bat Mystacina tuberculata on fruit and possibly nectar". New Zealand Journal of Zoology 3:391–398.
5. ^ O'Donnell, C. F J., J. Christie, C. Corben, J. A. Sedgeley, and W. Simpson. (1999) "Rediscovery of short-tailed bats (Mystacina sp.) in Fiordland, New Zealand: preliminary observations of taxonomy, echolocation calls, population size, home range, and habitat use". New Zealand Journal of Ecology 23:21–30
6. ^ ^{a b} Greaves, G. J. (2005) "Modelling the distribution of New Zealand bats as a function of habitat selection". M.S. thesis, University of Otago, Dunedin, New Zealand.
7. ^ ^{a b} Daniel, M. J. and G. R. Williams. (1984) "A survey of the distribution, seasonal activity and roost sites of New Zealand bats". New Zealand Journal of Ecology 7:9–25.
8. ^ Arkins, A. M., A. P. Winnington, S. Anderson, and M. N. Clout. (1999) "Diet and nectarivorous foraging behaviour of the short-tailed bat (Mystacina tuberculata)". Journal of Zoology (London) 247:183–187.
9. ^ ^{a b c d} Daniel, M. J. 1979. "The New Zealand short-tailed bat Mystacina tuberculata: a review of present knowledge". New Zealand Journal of Zoology 6:357–370.
10. ^ Ecroyd, C. E. (1995) "Dactylanthus and bats: the link between two unique endangered New Zealand species and the role of the community in their survival". Pp. 78–87 in Nature conservation 4: the role of networks (A. D. Saunders, J. L. Craig, and E. M. Mattiske, eds.). Surrey Beatty and Sons, Chipping Norton, New South Wales, Australia.
11. ^ Daniel, M. J. (1990) "Order Chiroptera". Pp. 114–137 in The handbook of New Zealand mammals (C. M. King, ed.). Oxford University Press, Auckland, New Zealand.
12. ^ ^{a b} Hutson, A. M., S. P. Mickleburgh, and P. A. Racey. (2001) "Microchiropteran bats: global status, survey and conservation action plan". World Conservation Union, Species Survival Commission, Chiroptera Specialist Group, Gland, Switzerland.
13. ^ Molloy, J. (1995) Bat (Peka peka) recovery plan (Mystacina, Chalinolobus). Threatened Species Recovery Plan Series 15. Department of Conservation, Wellington, New Zealand.
14. ^ Lloyd, B. D. and S. M. McQueen. (2002) "Measuring mortality in short-tailed bat (Mystacina tuberculata) as they return from foraging after an aerial 1080 possum control operation". New Zealand Journal of Ecology 26:53–59.

External links

• New Zealand Bats, P. D. Dwyer. Tuatara: Volume 8, Issue 2, May 1960
• Specimens of short tailed bats in the collection of the Museum of New Zealand Te Papa Tongarewa.
• Video clips of little bats feeding.