Mouse-tailed bats
| Mouse-tailed bats | ||||||||||||
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Rhinopoma microphyllum |
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| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Rhinopomatidae | ||||||||||||
| Bonaparte , 1838 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Rhinopoma | ||||||||||||
| E. Geoffroy , 1818 |
The mouse- tailed bats ( Rhinopoma ) are a genus of relatively primitive bats . They are not closely related to any other bats and are therefore classified as a separate family, Rhinopomatidae. This group includes four species that live in Africa and southern Asia .
features
General physique
Like all bats, they have a flight membrane between the forelimbs and the torso, which enables them to fly actively. The name-giving feature of these animals is the tail, which is the longest of all bats compared to their body size. Since the uropatagium (the skin between the legs) is very small, the tail protrudes “like a mouse” far back and gives a whip-like impression. The fur of these animals is dark brown or gray-brown in color, with the underside being a little lighter. They are hairless on the face and back of the abdomen. The calcar , a thorn on the ankle that serves to tighten the tail membrane, is missing from them. Other special features that distinguish them from most other bats are the still spherical shoulder joint , the non-reduced fibula and the fact that the second finger still has two phalanges.
These bats reach a head body length of 5 to 9 centimeters, the tail becomes 4 to 8 centimeters long. Their wingspan is 28 to 35 centimeters and their weight 6 to 14 grams.
Head and teeth
| Tooth formula | I. | C. | P | M. | |
|---|---|---|---|---|---|
| 28 | = | 1 | 1 | 1 | 3 |
| 2 | 1 | 2 | 3 | ||
The large ears are grooved and have a well-developed tragus . They can be folded forward and protrude beyond the tip of the nose. This is provided with a small, round nose blade . The nostrils can be closed - presumably an adaptation to the dry habitat. The muzzle gives a blunt, rounded impression, which is mainly due to the widened nasal bone . The intermaxillary bone (premaxillary) is separated from the upper jaw .
The teeth are arranged similarly to those of other insectivorous bats. In the upper jaw they have one incisor , one canine , one premolar and three molars per jaw , in the lower jaw two incisors, one canine, two premolars and three molars. This results in the tooth formula opposite.
distribution and habitat
Mouse-tailed bats are native to northern Africa and southern Asia . In Africa their distribution area extends from Morocco and Egypt to Nigeria and Kenya , in Asia they can be found without doubt on the Arabian Peninsula , Iran , Afghanistan , Pakistan and India . It is unclear to what extent they occur in Southeast Asia . There are dubious finds from Myanmar , Thailand and Malaysia . Their habitats are mostly dry or semi-arid, treeless regions.
Way of life
General
Mouse-tailed bats, like most bats, are nocturnal. They sleep in caves, crevices and structures such as houses or pyramids , whereby, unlike other bats, they cling to their thumbs and feet. One species, Rhinopoma hardwickei, sleeps alone or in small groups of four to ten animals, often members of the same sex. Several groups can join together to form loose associations of up to 100 individuals. It is known that the other species are often in their day quarters in their thousands.
In autumn, they store fat reserves, especially in the hairless areas on the stomach. In doing so, their weight can double its normal value. In addition, they can fall into a torpor (cold rigidity) during the cooler months . Thanks to these adaptations, they can survive immobile for several weeks without ingesting food or water.
food
These bats feed exclusively on insects , which they - like all bats - find by means of echolocation during flight. Compared to other bats, their flight is fluttery and wavy, while they stay around six to nine meters above the ground.
Reproduction
The mouse-tailed bats reproduce once a year and are seasonal. The mating takes place in spring, the gestation period is around 100 to 120 days, so that the birth usually takes place in July or August. As with most bats, a single hatchling is usually born. Presumably the females form maternity roosts as with other bats, which means that they form their own groups of females at birth and during the first few weeks of rearing their young.
Young animals are suckled for around two months, females reach sexual maturity at nine months and males at 16 to 17 months.
Mouse-tailed bats and humans
Due to their dry, sparsely populated habitat, these animals are less threatened than other bat species. Only one of the four species, Rhinopoma macinnesi , is considered endangered ( vulnerable ) by the IUCN . Like many bats, they are partly cultural followers and often sleep in houses, wall niches or ruins. They have been documented in the Egyptian pyramids for over 3000 years.
Systematics
External system
Because of the long, free tail and other anatomical features, mouse-tailed bats were considered to be one of the most primitive groups of bats. However, according to molecular genetic data, they belong to the horseshoe bat-like (Rhinolophoidea) and are closely related to the pig- nosed bat ( Craseonycteridae) and the large-leaf noses (Megadermatidae).
Internal system
The mouse-tailed bats are divided into four types:
- Rhinopoma hardwickii is native to northwestern Africa ( Morocco and Senegal ) via Egypt and the Arabian Peninsula to southern Asia ( Afghanistan , India and Myanmar ).
- Rhinopoma macinnesi lives in Ethiopia , Kenya and Somalia . The IUCN lists the species as endangered.
- Rhinopoma microphyllum is the largest species and occurs in northern Africa (Morocco and Egypt to Nigeria and Sudan ) and in southwest and southern Asia (to southern India ), probably also in Southeast Asia .
- Rhinopoma muscatellum isnative to Oman , Iran and Afghanistan . It is the smallest member of its genus.
There are some lost specimens believed to have been found in Southeast Asia ( Myanmar , Thailand, and Malaysia ). It is unclear which species it was, probably R. hardwickei or R. microphyllum .
Fossil ancestors of the mouse-tailed bats have not yet been discovered.
literature
- Ronald M. Nowak: Walker's Mammals of the World. 2 volumes. 6th edition. Johns Hopkins University Press, Baltimore MD et al. 1999, ISBN 0-8018-5789-9 .
- Erwin Kulzer: Chiroptera, bats. In: Wilfried Westheide, Reinhard Rieger (Ed.): Special Zoology. Part 2: vertebrates or skulls . Spectrum Akademischer Verlag, Heidelberg - Berlin 2004, 712 pages, ISBN 3-8274-0307-3 .
Individual evidence
- ^ Teeling, EC; Springer, M .; Madsen, O .; Bates, P .; O'Brien, S .; Murphy, W. (2005). A Molecular Phylogeny for Bats Illuminates Biogeography and the Fossil Record . Science. 307 (5709): 580-584. doi: 10.1126 / science.1105113
Web links
- Mouse-tailed bats on Animal Diversity Web
- Endangerment level of the individual species in the IUCN Red List of Threatened Species .
- Illustration of a mouse-tailed bat
