Southern bent-wing bat

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Southern bent-wing bat
Southern bentwing bat.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Chiroptera
Family: Miniopteridae
Genus: Miniopterus
Species:
M. orianae
Subspecies:
M. o. bassanii
Trinomial name
Miniopterus orianae bassanii
(Cardinal & Christidis, 2000)

The southern bent-wing bat (Miniopterus orianae bassanii) is one of two subspecies of the Australasian bent-wing bat. [1] Its population size has declined rapidly since the 1950s, and it is classified as critically endangered by the Australian government. [2]

Contents

Taxonomy

In 2000, the common bent-wing bat of Australia was revised into three subspecies, including the southern bent-wing bat. [3] However, it is now recognized as a subspecies of the Australasian bent-wing bat (Miniopterus orianae). [1] There is evidence to suggest that it is reproductively isolated from the other Australian subspecies, and warrants elevation to its own species based on genetics. [2]

Etymology

The subspecies name is derived from the border between this subspecies and the eastern bent-wing bat, the Bassian volcanic plains. [3]

Description

The southern bent-wing bat is slightly larger than the other two subspecies of bent-wing bats in Australia. [3] It has an average weight of 15.7g and average forearm length of 47.6mm. [4] It roosts in caves and rock crevices. [2] Its range is restricted to southeastern South Australia and southwestern Victoria. [5] Their lifespans can be at least 20 years, as determined by the recapture of banded bats. [6]

Reproduction

Southern bent-wing bat pups.jpg

Mating occurs in the autumn, but the embryo doesn't begin to grow until the spring due to delayed implantation. [7] Females do not reproduce until their second year. [7] The offspring, called pups, are born at 20% of their adult size, and reach full size by ten weeks of age. [7] Southern bent-wing bats rely heavily on cave structure, choosing caves that allow high heat and humidity, which promotes development of their young, which are born hairless. [8] The pups begin learning to fly at seven weeks old. [7]

Conservation

The southern bent-wing bat is one of only five mammals in Australia to have the designation critically endangered; listing occurred in 2007. [2] During the summer breeding season, most of the species now forms maternity colonies in two caves, Bat Cave in Naracoorte Caves National Park and Starlight Cave in Warrnambool. [2] [9] The Naracoorte site hosted up to 200,000 individuals in the 1950s and 1960s, but in 2009, there were an estimated 20,000 individuals. [2] An immense breeding colony once existed at the Widderin caces near Skipton, as the Chief Protector of Aborigines in Victoria, George Augustus Robinson, discovered in the mid 1840s. That habitat ceased to function as a colony by the late 1860s. [10]

Reasons for decline

One possible cause of the species decline is climate change. In December 2006, over three hundred dead or dying bats were on the floor of Bat Cave, with other emaciated individuals still hanging on the walls. [9] The cause of this mortality was attributed to lack of insects due to drought, in addition to a record number of cold nights that further suppressed insect activity. [9] There has also been a significant decrease in genetic variation in recent years, which could cause further decline of the subspecies. [11] Another possible cause of decline of this subspecies is guano mining in Australia, which frequently involved changing the shapes of caves to make extraction easier. [2] Guano mining changed the cave environments by lowering their humidity, which possibly made them inhospitable to bat colonies. [12] It is unknown if pesticide or heavy metal exposure is contributing to the decline of this subspecies, although DDT and its related compounds DDD and DDE have been found in their guano, livers, pectoral muscles, brains, and fat tissues. [13]

Future threats

A major concern for conservation of this subspecies is the potential arrival of white-nose syndrome, which has killed millions of bats in North America since its introduction in 2007. A risk assessment stated that it was "Almost Certain" that white-nose syndrome would arrive in Australia by 2027. [14] While many caves in Australia would be too warm for the cold-loving fungus that causes white-nose syndrome, the caves in southern Australia are colder and suitable for growth of the fungus. [14] The risk assessment predicted that of all cave-roosting bat species in Australia, the arrival of white-nose syndrome would have the most severe effect on the southern bent-wing bat. [14]

Management actions

Fences have been placed outside of Bat Cave to deter foxes and rabbits from entering. [2] Totally closing off cave entrances with bat-accessible gates, while effective for managing some species, is not effective for this subspecies, as it avoids caves with gates. [2] Human access to Bat Cave is strictly regulated to minimize disturbance to the maternity colony, but Starlight Cave is on private land and therefore less protected. [2] Most critically, researchers are seeking to determine what is responsible for the drastic decline of the subspecies, so more focused conservation actions can be implemented. [2]

Related Research Articles

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The gray bat is a species of microbat endemic to North America. The creature once flourished in caves all over the southeastern United States, but due to human disturbance, gray bat populations declined severely during the early and mid portion of the 20th century. 95% of gray bats now only roost in 11 caves. M. grisescens has been listed as federally endangered by the U.S. Fish and Wildlife Service since 1976, and is protected under the Endangered Species Act. Gray bat populations were estimated at approximately 2 million bats around the time they were placed on the Endangered Species list. By the early 1980s populations of gray bats dropped to 1.6 million. With conservation efforts in place, in 2004, gray bat populations were estimated to have reached 3.4 million.

Big brown bat Species of vesper bat (Eptesicus fuscus)

The big brown bat is a species of vesper bat distributed widely throughout North America, the Caribbean, and the northern portion of South America. It was first described as a species in 1796. Compared to other microbats, the big brown bat is relatively large, weighing 15–26 g (0.53–0.92 oz) and possessing a wingspan of 32.5–35 cm (12.8–13.8 in). Big brown bats are insectivorous, consuming a diverse array of insects, particularly night-flying insects, but especially beetles. Some of the beetles it consumes are serious agricultural pests, including cucumber beetles. They are nocturnal, foraging for prey at night and roosting in sheltered areas during the day such as caves, tunnels, tree cavities, and human structures. Their breeding season is in the fall, shortly before their annual hibernation. After hibernation ends in the spring, females form maternity colonies for giving birth to young. Oftentimes only one offspring is produced per litter, though twins are common in the Eastern US. Lifespans of 6.5 years are considered average.

Ghost bat Species of bat

The ghost bat is a flying mammal found in northern Australia. The species is the only Australian bat that preys on large vertebrates – birds, reptiles and other mammals – which they detect using acute sight and hearing, combined with echolocation, while waiting in ambush at a perch. The wing membrane and bare skin is pale in colour, their fur is light or dark grey over the back and paler at the front. The species has a prominent and simple nose-leaf, their large ears are elongated and joined at lower half, and the eyes are also large and dark in colour. The first description of the species was published in 1880, its recorded range has significantly contracted since that time.

Chocolate wattled bat Species of bat

The chocolate wattled bat, species Chalinolobus morio, is a bat allied to the family Vespertilionidae. It is found only in Australia, including the island Tasmania, and widespread in southern regions. It is known to reside from sea level to at least 1,570 metres (5,150 ft) in Victoria.

Ussuri tube-nosed bat Species of bat

The Ussuri tube-nosed bat is a species of vesper bat in the family Vespertilionidae. It is threatened by habitat loss. It is the only species of bat that hibernates in snowbanks.

Common bent-wing bat Species of mammal

The common bent-wing bat, also known as the Schreibers's long-fingered bat or Schreibers's bat, is a species of insectivorous bat. They appear to have dispersed from a subtropical origin and distributed throughout the southern Palearctic, Ethiopic, Oriental, and Australian regions. In Europe, it is present in the southern half on the continent from Iberia to the Caucasus, with the largest populations found in the warmer Mediterranean area. The common and scientific names honor Carl Franz Anton Ritter von Schreibers.

Eastern small-footed myotis Species of bat

The eastern small-footed bat is a species of vesper bat. It can be found in southern Ontario and Quebec in Canada and in mountainous portions of the eastern United States from New England to northern Georgia, and westward to northern Arkansas. It is among the smallest bats in eastern North America and is known for its small feet and black face-mask. Until recently, all North American small-footed Myotis were considered to be "Myotis leibii". The western population is now considered to be a separate species, Myotis ciliolabrum. The Eastern small-footed bat is rare throughout its range, although the species may be locally abundant where suitable habitat exists. Studies suggest white-nose syndrome has caused declines in their populations. However, most occurrences of this species have only been counted within the past decade or two and are not revisited regularly, making their population status difficult to assess. Additionally, most bat populations in the Eastern U.S. have been monitored using surveys conducted in caves and mines in the winter, but Eastern small-footed bats hibernate in places that make them unlikely to be encountered during these surveys. Perhaps as a result, the numbers of Eastern small-footed bats counted in winter tend to be low and they are relatively variable compared to other species of bats. Many biologists believe the species is stable, having declined little in recent times, but that it is vulnerable due to its relatively restricted geographic range and habitat needs.

Smaller horseshoe bat Species of bat

The smaller horseshoe bat is a species of bat in the family Rhinolophidae. It is found in Australia and Papua New Guinea.

Guano Excrement of seabirds and bats

Guano is the accumulated excrement of seabirds and bats. As a manure, guano is a highly effective fertilizer due to its exceptionally high content of nitrogen, phosphate, and potassium: key nutrients essential for plant growth. Guano was also, to a lesser extent, sought for the production of gunpowder and other explosive materials.

<i>Miniopterus</i> Genus of bats

Miniopterus, known as the bent-winged or long winged bats, is the sole genus of the family Miniopteridae. They are small flying insectivorous mammals, micro-bats of the order Chiroptera, with wings over twice the length of the body. The genus had been placed in its own subfamily among the vespertilionid bats, as Miniopterinae, but is now classified as its own family.

Little brown bat Species of mammal found in North America

The little brown bat or little brown myotis is a species of mouse-eared microbat found in North America. It has a small body size and glossy brown fur. It is similar in appearance to several other mouse-eared bats, including the Indiana bat, northern long-eared bat, and Arizona myotis, to which it is closely related. Despite its name, the little brown bat is not closely related to the big brown bat, which belongs to a different genus.

Virginia big-eared bat Subspecies of bat

The Virginia big-eared bat is one of two endangered subspecies of the Townsend's big-eared bat. It is found in Virginia, West Virginia, North Carolina, and Kentucky. In 1979, the US Fish and Wildlife Service categorized this as an endangered species. There are about 20,000 left and most of them can be found in West Virginia. The Virginia Big-Eared Bat is the state bat of Virginia.

Ozark big-eared bat Subspecies of bat

The Ozark big-eared bat is an endangered species found only in a small number of caves in Arkansas, Oklahoma and Missouri, the southern central United States. Also known as the western big-eared bat, the long-eared bat, and the lump-nosed bat, its appearance is defined by a pair of outsize ears and a lump-adorned nose. The Ozark big-eared bat is the largest and reddest of the five subspecies of Corynorhinus townsendii and is medium-sized and weighs from 0.2 to 0.5 ounces. It has very large, 1-inch-long ears that connect at the base across the forehead. The snout has large, prominent lumps above the nostrils. These particular bats feed on moths and other insects; they forage along forest edges.

<i>Myotis septentrionalis</i> Species of mammal

Myotis septentrionalis, known as the northern long-eared bat or northern myotis, is a species of bat native to North America. There are no recognized subspecies. The northern long-eared bat is about 3–3.7 inches in length, with a wingspan of 9–10 inches. It is distinguishable by its long ears when comparing it to other bats in its genus. This species is commonly found in the northern United States and Southern Canada east of British Columbia. The geographic range includes 37 states.

Eastern bent-wing bat Species of bat

The eastern bent-wing bat, is a species of vesper bat in the family Vespertilionidae. It is found in South Asia, Far-east Asia, the east Caucasus Mountains and also in Southeast Asian regions.

The Australasian bent-wing bat is a species of vesper bat in the family Miniopteridae. It is found in Australia and in Southeast Asia.

Maternity colony Temporary association of reproductive female bats

A maternity colony refers to a temporary association of reproductive female bats for giving birth to, nursing, and weaning their pups. The colonies are initiated by pregnant bats. After giving birth, the colony consists of the lactating females and their offspring. After weaning, juveniles will leave the maternity colony, and the colony itself will break apart. The size of a maternity colony is highly variable by species, with some species forming colonies consisting of ten or fewer individuals, while the largest maternity colony in the world in Bracken Cave is estimated to have over 15 million bats.

Miniopterus maghrebensis, also known as the Maghrebian bent-wing bat, is a species of bat found in North Africa.

Miniopterus pallidus, the pale bent-wing bat, is a species of bat found in Middle-East. Until 2010, it was considered as a sub-species of M. schreibersii.

References

  1. 1 2 Jackson, S.; Groves, C. (2015). Taxonomy of Australian Mammals. Australia: CSIRO Publishing. ISBN   978-1-4863-0014-3.
  2. 1 2 3 4 5 6 7 8 9 10 11 Lumsden, L. F., & Jemison, M. L. (2015). National Recovery Plan for the Southern Bent-wing Bat Miniopterus schreibersii bassanii.
  3. 1 2 3 Cardinal, B. R., & Christidis, L. (2000). Mitochondrial DNA and morphology reveal three geographically distinct lineages of the large bentwing bat (Miniopterus schreibersii) in Australia. Australian Journal of Zoology, 48(1), 1-19.
  4. ↑ Churchill, S. (2009). Australian bats. Allen and Unwin. Crows Nest, NSW.
  5. ↑ Codd, J. R., Sanderson, K. J., & Branford, A. J. (2003). Roosting activity budget of the southern bent-wing bat (Miniopterus schreibersii bassanii). Australian Journal of Zoology, 51(3), 307-316.
  6. ↑ Lumsden, L., & Gray, P. (2001). Longevity record for a Southern Bent-wing Bat Miniopterus schreibersii bassanii. The Australasian Bat Society Newsletter, 16, 43-4.
  7. 1 2 3 4 Dwyer, P. D. (1963). The breeding biology of Miniopterus schreibersi blepotis (Termminck)(Chiroptera) in north-eastern NSW. Australian Journal of Zoology, 11(2), 219-240.
  8. ↑ Dwyer, P. D., & Hamilton-Smith, E. (1965). Breeding Caves and Maternity Colonies of the Bent-winged Bat in South-eastern Australia.
  9. 1 2 3 Bourne, S., & Hamilton-Smith, E. (2007). Miniopterus schreibersii bassanii and climate change. Aust. Bat Soc. Newsl, 28, 67-69.
  10. ↑ Ian D. Clark, 'The abode of malevolent spirits and creatures – caves in Victorian Aboriginal social organization,' Helictite, Vol. 40, No. 1, pp. 3-10, p.3.
  11. ↑ Wood, R., and Appleton, B. (2010). Taxonomy, population genetics and conservation of the Critically Endangered Southern Bent-wing Bat (Miniopterus schreibersii bassanii). Abstract from the 14th Australasian Bat Society Conference, Darwin July 2010. The Australasian Bat Society Newsletter 35,17.
  12. ↑ Baudunette, R. V., Wells, R. T., Sanderson, K. J., & Clark, B. (1994). Microclimatic conditions in maternity caves of the bent-wing bat, Miniopterus schreibersii: an attempted restoration of a former maternity site. Wildlife Research, 21(6), 607-619.
  13. ↑ Mispagel, C., Allinson, M., Allinson, G., Iseki, N., Grant, C., & Morita, M. (2004). DDT and metabolites residues in the southern bent-wing bat (Miniopterus schreibersii bassanii) of south-eastern Australia. Chemosphere, 55(7), 997-1003.
  14. 1 2 3 Holz, P. Hufschmid, J., Boardman, W., Cassey, P., Firestone, S. Lumsden, L., Prowse, T., Reardon, T., Stevenson, M. 2017. Qualitative risk assessment: White-nose syndrome in bats in Australia. Wildlife Health Australia.
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