Brants' whistle rat
| Brants' whistle rat | ||||||||||||
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Brants' whistle rat |
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| Parotomys brantsii | ||||||||||||
| ( A. Smith , 1834) |
The Brants' whistling rat ( Parotomys brantsii ), also called Karru rat , is a larger member of the rodent order with a body length of 12.5 to 16.5 centimeters and a tail length of 7.5 to 10.5 centimeters .
features
Brants' whistling rat is a medium to large species of rodent, although the animals in South Africa are larger and heavier than those in Namibia. They also exhibit sexual dimorphism, with males larger than females. Males in South Africa reach an average head-trunk length of 21.5 centimeters with a range of 17.7 to 24.9 centimeters. The tail averages 87 millimeters in length, ranges from 70 to 154 millimeters, and weighs 84 to 206 grams, an average of 138 grams. The females in South Africa reach an average head-trunk length of 20.2 centimeters with a range of 16.1 to 23.6 centimeters. The tail has an average length of 82 millimeters, the span is 58 to 97 millimeters, and the weight is 80 to 214 grams, an average of 121 grams.
The fur of the animals is long and dense with hair lengths of six to seven millimeters. The back fur has a siena- yellow basic color and is speckled black-brown. The individual hairs have a gray base and a yellow tip, plus long black hair, especially near the back line. The sides of the body are a little paler and the abdomen is gray-white in color. The head is gray-white with a blunt snout region, the nose areas and forehead are reddish in color. The ears are large, rounded and darkly pigmented with short brown and pale hair. The legs are short. The front feet have four long and slender fingers with long claws, the first finger is reduced and only indistinctly recognizable. The feet have five well-formed toes with long claws. The tail is short with about 63% of the head-trunk length. It is hairy, dark brown on the top and reddish-brown on the sides and on the underside. The females have two pairs of teats in the groin area.
From the very similar Littledales whistling rat ( Parotomys littledalei ), Brants' whistling rat differs only very little. It is slightly heavier but of the same size and has a slightly more pointed nose and ears, and the teeth, especially the molars and upper incisors , differ in their formation. The alarm calls from Brants' whistle rat are shorter and not as high-pitched as Littledale's whistle rat.
distribution and habitat
The range of this species are the deserts and semi-deserts of the Karoo and the southern Kalahari in the south of Namibia , the southwest of Botswana and the western and northern Cape provinces of South Africa .
Way of life
Brants' whistle rat lives in arid regions with hard soils in the Nama Karoo and southern Kalahari. In large parts, the occurrence is closely linked to the occurrence of the shrubby Rhigozum trichotomum in the area of dunes and dry river valleys. The distribution areas are largely limited to regions with an annual rainfall of less than 300 millimeters. The animals are diurnal and look for food mainly in the morning and late afternoon. They live in large, underground, self-dug cave systems. In the event of danger, the animals warn each other with high-pitched warning sounds.
nutrition
The animals look for food, especially grass and other low vegetation, on the surface of the earth in the area of their burrows. Brants' whistle rat feeds exclusively on herbivores , i.e. on parts of plants. The range of plants is extensive and includes parts of woody shrubbery, annuals, grasses and various succulents . Seeds and other dry food are avoided, and in hot summer they dig for tubers in the ground. Foraging takes place almost exclusively in the immediate vicinity of their burrows and the animals rarely move more than 30 centimeters from the entrances, but in some regions they also search between several burrows and change entrances. This creates frequently used connecting paths between the individual buildings.
The animals usually pull the plant parts down to them and then eat them, rarely climbing into low bushes. Larger parts of the plant transport the animals to the entrance. Fresh material is eaten directly, the animals stow larger parts of the plant in their burrow or, more rarely, above ground in the area of the entrance near the nest chamber. Most of the food reserves are collected in the late afternoon and are believed to serve as a night supply.
Reproduction and development
The reproduction time and intensity of the animals depends on the environmental conditions and is primarily linked to precipitation. In areas with summer rainfall, such as the southern Kalahari, the highest reproduction rate is in summer. In the Namaqualand in South Africa, where the precipitation mainly takes place in winter, there are correspondingly the highest reproduction rates in winter to spring. The female can have at least 4 litters each year with 3 to 4 young animals. The gestation period is about 38 days, there is no information about the birth weight. The animals start foraging outside the burrows after about 7 days and gain about 1.2 grams per day in weight until they have reached about 55% of adult weight after six to seven weeks and are independent of the mother. They reach sexual maturity at around 35 days, at the same time they can store their own supplies, collect nest material and defend the nest against conspecifics. Shortly afterwards they leave the mother's den. The females live for about 1 to 2 years and can produce young animals over the entire period.
Predators and parasites
Like other small rodents, Brants' whistle rat is a common prey of numerous predators, including predators , various reptiles, and birds of prey . Among the main predators include birds of prey of the Great Singhabicht ( Melierax canorus ), the Jackal Buzzard ( Buteo rufofuscus ), the Lanner Falcon ( Falco biarmicus ) and the booted eagle ( Hieraaetus pennatus ), added the Barn Owl ( Tyto alba ) and the spotted eagle owl ( Bubo africanus ) among the owls and the black-necked heron ( Ardea melanocephala ). The fox mongoose ( Cynictis penicillata ), the honey badger ( Mellivora capensis ), the black-backed jackal ( Canis mesomelas ), the black cat ( Felis silvestris lybica ) are the most important predatory mammals that hunt the whistle rat. In parts of the distribution area it is also the main prey of the caracal ( Caracal caracal ), which feeds on the animals especially in the hot summer period and organizes its hunting expeditions based on their colonies. Added puff adders ( Bitis arietans ), African spitting cobras ( Naja nigricollis ) Kapkobras ( Naja nivea ) and mole snakes ( Pseudaspis cana ).
Brants' whistling rat is also parasitized by at least eight species of fleas and three species of ticks . Animals also play a role as natural vectors of the plague .
Systematics
Brants' whistling rat is classified as a separate species within the genus of Karru rats ( Parotomys ), which consists of two species. The first scientific description comes from Andrew Smith from 1834, who described the species as Euryotis brantsii on the basis of individuals from Namakwa ( Little Namaqualand ) in the mouth of the River Orange in the South African province of North Cape .
Status, threat and protection
Brants' whistle rat is classified as Least Concern by the International Union for Conservation of Nature and Natural Resources (IUCN). This is justified with the large distribution area and the occurrence in several protected areas as well as the lack of population risks for the species. Within the distribution area it is very common and it is viewed locally as a pest.
The stocks fluctuate strongly depending on the environmental conditions. In ecologically favorable years, the animals can reach population densities of 50 animals per hectare and even quadruple with a good breeding season.
supporting documents
- ↑ a b c d e f g h i j k l m n Tim P. Jackson: Parotomys brantsii - Brants's Whistling Rat. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume III. Rodents, Hares and Rabbits. Bloomsbury, London 2013, pp. 597-599; ISBN 978-1-4081-2253-2 .
- ↑ HIAS Melville, Jdu P. Bothma: Possible optimal foraging for Brants's whistling rats by caracals in the Kgalagadi Transfrontier Park. African Zoology 41 (1), 2006; Pp. 134-136. doi : 10.3377 / 1562-7020 (2006) 41 [134: POFFBW] 2.0.CO; 2 .
- ↑ Parotomys brantsii ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. . In: Don E. Wilson , DeeAnn M. Reeder (Eds.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
- ↑ a b Parotomys brantsii in the IUCN Red List of Threatened Species 2014.3. Posted by: N. Coetzee, 2008. Retrieved April 6, 2015.
literature
- Tim P. Jackson: Parotomys brantsii - Brants's Whistling Advice. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume III. Rodents, Hares and Rabbits. Bloomsbury, London 2013, pp. 597-599; ISBN 978-1-4081-2253-2 .
Web links
- Parotomys brantsii inthe IUCN Red List of Threatened Species 2014.3. Posted by: N. Coetzee, 2008. Retrieved April 6, 2015.