Nile rat
| Nile rat | ||||||||||||
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Nile rat ( Arvicanthis niloticus ) in Tanzania |
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| Scientific name | ||||||||||||
| Arvicanthis niloticus | ||||||||||||
| ( E. Geoffroy , 1803) |
The Nile rat or Nile grass rat ( Arvicanthis niloticus ) is a rodent of the genus Kusurats found primarily in much of Africa . The mainly diurnal species eats mainly plant parts of grasses and vegetables. It is therefore considered an agricultural pest in Africa and can also transmit diseases and parasites to humans and crops. In research, the species is used as an experimental animal.
features
With a head-body length of 111 to 238 mm, a tail length of 92 to 170 mm and a weight of 55 to 258 g, the Nile rat is a medium-sized, powerful animal with a rat-like appearance. It has hind feet 23 to 38 mm long and ears 12 to 24 mm long. The hairs on the upper side are dark brown at the root, tawny in the middle and black at the tips. This results in a mottled light brown coat color with lighter and darker spots. There are often reddish tints on the rump. Some specimens have a distinct black dorsal stripe on their backs. The Nile rat has light gray to whitish fur on its underside. The tail is also dark on top and light brown on the bottom. The very small, but not rudimentary, fifth finger is characteristic of the front paws. There are no grooves on the incisors. Females have two teats on the chest and four in the groin area.
distribution
The range extends across the Sahel region from Senegal and southern Mauritania through Mali , Niger , northern Nigeria , Chad , southern Sudan and southern Sudan to Ethiopia . It continues through northeastern Democratic Republic of the Congo , Uganda and western Kenya to northern Tanzania . Populations located further south in central Tanzania and Zambia need to be assessed as belonging to this species. Isolated populations are known from southwest Yemen and Oman , as well as various areas of the Sahara . North of the region described, this rodent is common in a narrow area along the Nile .
The Nile rat reaches 1600 meters in the Ethiopian highlands. It inhabits savannas , steppes , other grassy areas, and visits hedges, scrubland, and arable land. The species is occasionally found in villages, although it avoids buildings.
way of life
The species builds grass nests on the ground or in simple burrows and is mainly diurnal. It creates trails and mainly eats leaves, stems and seeds of grasses and vegetables. When trees, like the desert date ( Balanites aegyptiaca ), bear fruit in the dry season, they are reached by climbing. In the rainy season, up to 20 percent of the diet can consist of insects .
The specimens temporarily form family groups with several females and males, but are hostile to strange individuals of the same sex. Depending on distribution, females can breed at all times of the year or only for a limited number of months. In general, most offspring are born during the rainy season . The average number of pups per litter varies between 4 and 7. They are born at 21 to 23 days of gestation and receive breast milk for about two months. Wild specimens rarely live more than a year.
The predators of the Nile rat include various predators such as mongooses , barn owls , black-shouldered kites , crested eagles , sparrow-hawk buzzards or real cobras , as well as snakes of the genus Psammophis .
threat
There are no threats to the population of the Nile rat. Because the overall population is estimated to be large, the species is listed as Least Concern by the IUCN .
Nile rat and human
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In much of Africa, Nile rats are considered an agricultural pest and programs exist to control the species. In addition, the Nile rat has also been linked to the transmission of several diseases and parasites to humans and crops, including bubonic plague in Egypt, the paired fluke species Schistosoma mansoni and the Rice Yellow Mottle Virus (RYMV). Transmission of the plague bacterium Yersinia pestis to humans is usually via an intermediate host through the bite of a rat flea . RYMV is a viral infection of rice plants first reported in Kenya in 1966 and can be transmitted from plant to plant by animals such as rats and beetles, among others.
Because of its rapid reproductive capacity, small size, and diurnal activity, the Nile rat has value as a laboratory animal. Commonly used brown rats or house mice are nocturnal, so Nile rats are more similar in behavior to humans and many other mammals in this regard. For example, Nile rats have been used to study circadian rhythms , and together with fats, sand rats have been used to study obesity and diabetes .
systematics
The species was first described in 1803 by the French zoologist Étienne Geoffroy Saint-Hilaire . The type locality is Egypt. The Nile rat belongs to the genus of the kusurat, within which it has the largest distribution area.
Synonyms used in the literature include:
- Arvicanthis abyssinicus subsp. centrosus Hollister , 1916
- Arvicanthis abyssinicus subsp. rubescens Wroughton , 1909
- Arvicanthis jebelae Heller , 1911
- Arvicanthis niloticus ( Desmarest , 1822)
- Arvicanthis niloticus subsp. Naso Pocock , 1934
- Arvicanthis testicularis subsp. solatus Thomas , 1925
- Hypudaeus variegatus Lichtenstein , 1823
- Isomys testicularis Sundevall , 1843
- Isomys variegatus subsp. Major Sundevall , 1843
- Isomys variegatus subsp. minor Sundevall , 1843
- Mus discolor Wagner , 1842
The fundamental number FNa is 62 or 64. The 62 chromosome arm form has been found east of Mali and Burkina Faso as far as Ethiopia and Egypt, while the other occurs to the west.
itemizations
- ↑ a b c Don E Wilson , DeeAnn M Reeder (eds): Mammal Species of the World . A taxonomic and geographic reference . 3rd Edition. 2 volumes. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 (English, Arvicanthis niloticus ).
- ^ a b c d e Granjon, Bekele & Ducroz: Arvicanthis niloticus . 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. 387-388; ISBN 978-1-4081-2253-2
- ↑ Chris & Mathilde Stuart, Stuart On Nature, 2016 A new mammal species record for Oman, the Nile grass rat (Arvicanthis niloticus) , accessed 13 December 2021
- ↑ a b c Arvicanthis niloticus in the IUCN Red List of Threatened Species 2016. Submitted by: Granjon, L., 2016. Retrieved December 8, 2021.
- ↑ Bakker W (1974). Characterization and ecological aspects of rice yellow mottle virus in Kenya (PhD thesis). Wageningen University. Abstracts
- ↑ Arvicanthis niloticus - African grass rat In: Animal Diversity Web , accessed 16 January 2022
- ↑ Alexandra Castillo-Ruiz, Matthew J. Paul, William J. Schwartz, Chapter 16 - In search of a temporal niche: Social interactions, Editor(s): Andries Kalsbeek, Martha Merrow, Till Roenneberg, Russell G. Foster, Progress in Brain Research, Elsevier, Vol. 199, 2012, pp. 267–280, ISSN 0079-6123, ISBN 9780444594273 , doi : 10.1016/B978-0-444-59427-3.00016-2 .
- ↑ Azka Khan, Kinza Waqar, Adeena Shafique, Rija Irfan, Alvina Gul, Chapter 18 - In Vitro and In Vivo Animal Models: The Engineering Towards Understanding Human Diseases and Therapeutic Interventions , Editor(s): Debmalya Barh, Vasco Azevedo, Omics Technologies and Bio-Engineering, Academic Press, 2018, pp. 431–448, ISBN 9780128046593 , doi : 10.1016/B978-0-12-804659-3.00018-X .
- ↑ Arvicanthis niloticus (É.Geoffroy, 1803) in GBIF Secretariat (2021). GBIF Backbone Taxonomy. Checklist dataset doi : 10.15468/39omei retrieved via GBIF.org on January 16, 2022.
web links
- Jessica St. John: Arvicanthis niloticus – African grass rat on Animal Diversity Web