Big-eared giant bulldog bat
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Preparation in the Naturalis Biodiversity Center |
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| Otomops martiensseni | ||||||||||||
| ( Matschie , 1897) |
The big-eared giant bulldog bat ( Otomops martiensseni ) is a species of bat from the family of bulldog bats , which is native to Africa. It is one of the three species of the genus Otomops found in Africa and one of two that are native to mainland Africa. The Madagascar giant bulldog bat ( Otomops madagascariensis ) was considered a subspecies until 1995, but is now considered a separate species.
The species was named after "Mr. Martienssen from the Royal Museum of Natural History", who found the holotype after which Paul Matschie described the species.
description
With a forearm length of 62–73 mm and a weight of 22.2–33.4 g, the big-eared giant bulldog bat is the largest representative of the genus Otomops . The ears are very large, about 40 mm long and connected to one another on an elongated, hump-like protrusion above the muzzle. The first and second premolar teeth are separated from each other by a gap, which distinguishes this type of Otomops species from the Asian region.
Compared to other species of the genus Otomops , the big-eared giant bulldog bat appears slimmer. The tail protrudes from the tail membrane by 33–42 mm. The auricle is furrowed like a bulge. Tragus and antitragus are absent; their function is completely replaced by a skin flap. The upper lip has many small folds and forms fleshy pockets on the sides. Both males and females have a skin pocket on their throat in which there are scent glands. However, the pocket is more developed in males than in females.
The fur is short and silky, mostly dark brown on the back with a light, often whitish collar over the shoulders. The belly is colored similarly to the back, but may appear lighter in some individuals. A light band runs along the back of the body from the shoulder to the knee.
Way of life
The big-eared giant bulldog bat , like most bats, is nocturnal and feeds on insects. In flight, the species produces echolocation calls in the range of 10-17 kHz, which are therefore audible to humans. Otomops martiensseni is found in a wide variety of habitats and can also make long migratory flights in dry areas to find enough food in the dry season. The species has relatively narrow wings and is therefore a fast flyer. In order to quickly lose altitude before entering the sleeping cave, the animals use a flight maneuver that pilots know as "fishtailing". One wing is oriented forwards and downwards, while the other wing is turned upwards and backwards, which leads to a spin.
The animals usually spend the day in caves in which they are in close physical contact with each other in groups of up to several hundred individuals. The species prefers the dark corners of the caves, which have relatively little air exchange. In Kenya , the species is known from two lava caves , where it was found either together with horseshoe bat and the round- leafed nose Triaenops persicus or as the only bat species. The bat guano produced by the animals was (and is partly still) commercially mined and sold to tea and coffee plantations. The associated direct disturbance and influence on the microclimate resulted in the animals completely disappearing in at least one of the two lava caves (on the Suswa shield volcano ). Other colonies are at risk from tourism and blockage of entrances. Only around the South African city of Durban is the species common and also found in buildings.
Although females of the big-eared giant bulldog bat, like other mammals, have two ovaries , the left one appears to be constantly atrophic and therefore not functional. Studies show that fetuses are located in the right horn of the uterus in all pregnant females examined . The gestation period lasts about three months, after which the females usually give birth to a single young in December. In contrast to many other bat species, the young animal does not cling to the mother after birth, but remains in the nursery with the young of other females.
distribution and habitat
The big-eared giant bulldog bat occurs south of the Sahara from the east coast of Africa to the west of the Ivory Coast and in the south to Zimbabwe . It is absent in the Republic of the Congo , Gabon and Equatorial Guinea . In South Africa it is only proven near the city of Durban . There is also an individual record for Yemen . It is classified by the IUCN as potentially endangered ("near threatened").
literature
- JK Long (1995): Otomops martiensseni . In: Mammalian Species , No. 493, pp. 1-5