Given its rapid breeding capabilities, diurnal activity patterns, and small size, A. niloticus has value in laboratory research in medicine, physiology, behavior, and other related fields. Most rodent-based research in these disciplines utilizes either Norway rats, or house mice. However, both of these species are nocturnal, and captive A. niloticus colonies have been validated as diurnal and are thus more similar in certain respects to humans and other diurnal mammals than typical lab rats or mice.
Positive Impacts: research and education
Arvicanthis niloticus is considered an agricultural pest throughout much of Africa, and active pest management programs are currently in effect. Also, this species has been implicated in the transmission of multiple human and crop diseases, including bubonic plague in Egypt, intestinal schistosomiasis, and Rice yellow mottle virus.
Negative Impacts: injures humans (causes disease in humans , carries human disease); crop pest
This species does not appear to be in any danger. The IUCN red list does not have a data entry for A. niloticus; however, it does list its congener, Arvicanthis blicki as near-threatened. The US Federal list and CITES have no information on A. niloticus.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Arvicanthis niloticus is capable of perceiving touch and scent at birth, and hearing and sight both develop around 6 to 7 days of age. Communication in A. niloticus has not been adequately studied. However, squeaks and distress calls have been observed to begin between 4 and 6 days of age, and vocalization may be involved in its communicative repertoire. Olfaction is a common form of communication in many mammals, including rodents, and may also be utilized by this species. Because these animals are social and diurnal, both visual and tactile communiation likely take place, although details of these forms of communication are not available in current literature.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
As noted above, there has been considerable argument over the taxonomy of the genus Arvicanthis. Much of the research conducted prior to the late 1990s on A. niloticus assumed it was the only species of Arvicanthis in existence. This may explain discrepencies in behavioral, circadian, and physical descriptions. Further genetic and morphometric research into the diversity of the genus Arvicanthis may alter the validity of this account.
Aside from serving as prey to some African carnivores, A. niloticus also serves other important, though perhaps less desirable, roles in its ecosystem. It is an agricultural pest and competes with other African rodents, primarily natal multimammate mice, and savanna gerbils, for both natural and cultivated resources. Arvicanthis niloticus thus has a strong impact on plant diversity. Senzota (1983) also proposed resource partitioning of grasses by A. niloticus and some African ungulates, including blue wildebeest and Thomson’s gazelles, to reduce competition between the rodents and ungulates.
Arvicanthis niloticus also serves as a host and/or vector for a variety of organisms, including fleas, parasitic worms, and viruses. It has been implicated in many plant and human disease outbreaks as a carrier of a multitude of diseases, such as bubonic plague in ancient Egypt, Rice yellow mottle virus in parts of Africa, and Schistosoma mansoni, which causes intestinal schistosomiasis, a disease that sometimes occurs in severe outbreaks in parts of Africa.
Commensal/Parasitic Species:
A. niloticus is primarily herbivorous, feeding on grasses, leaves and stems of flowering plants, seeds, the bark of some woody plants, and cultivated crops. Arthropods are also eaten by this species. As different food types vary in their availability seasonally, A. niloticus will alter the intake ratio of food types. This flexible, generalist approach may improve its competitive ability. Caching does not appear to be a predominant behavior in this species, but has been observed when larger food items were offered to wild individuals.
Animal Foods: insects
Plant Foods: leaves; wood, bark, or stems; seeds, grains, and nuts
Foraging Behavior: stores or caches food
Primary Diet: herbivore (Folivore )
The range of African grass rats, Arvicanthis niloticus, is traditionally held to extend along the Nile river valley and across most of sub-Saharan Africa, with the exception of the southern and southwestern regions of the continent. However, much debate over the number and range of species within the genus Arvicanthis has yet to be resolved, and the range of A. niloticus may be much more restricted. From genetic analysis, Ducroz, Volobouev, and Granjon (1998) claim this species occurs only in Egypt and northern West Africa, but Musser and Carleton (1993) argue that A. niloticus also inhabits regions including and surrounding Ethiopia.
Biogeographic Regions: ethiopian (Native )
As A. niloticus lives in colonial burrows, it requires some degree of ground cover, such as short bushes, trees, rocks, or termite mounds, under which it may nest. A variety of African habitats, including dry savanna, sub-desert, coastal scrub, open woodlands, grasslands, and cultivated areas, provide such protection. Exact altitudinal data are not reported, but A. niloticus is not believed to occur at high altitudes.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: desert or dune ; savanna or grassland ; scrub forest
Other Habitat Features: agricultural
Refinetti (2004) reports an average longevity of 2 years in captivity, with a standard deviation of 1 year for A. niloticus. Nowak (1999) claims that the longest lived individual of this species in captivity died at the age of 6 years and 8 months. Little is known about longevity in the wild; however, Packer (1983) estimates that females in one colony lived for an average of 10.2 months, with a maximum of 20 months.
Range lifespan
Status: wild: 20 (high) months.
Average lifespan
Status: wild: 10.2 months.
Range lifespan
Status: captivity: 6.6 (high) years.
Average lifespan
Status: captivity: 2 years.
Average lifespan
Status: wild: 10.2 months.
Average lifespan
Status: captivity: 2 years.
Average lifespan
Status: captivity: 6.7 years.
Rosevear (1969) described African grass rats as “medium-sized rats with stoutish bodies.” Adults of this species range in head and body length from 106 mm to 204 mm with an average of about 130 mm. Tail lengths range from 85% to 90% of the head and body length and average around 100 mm. Average mass of A. niloticus is 118 g, with a range of 50 g to 183 g. Males are slightly larger than females with reported average masses of 120 g to 123 g for males and 92 to 114 g for females.
Arvicanthis niloticus has a roundish head with large, round ears that are covered with short, fine fur. Incisors are not grooved; the snout is rather short, and the tail is covered in small, barely visible hairs. The hindfoot is well-developed, and the inner three hind toes are longer than the outer two. In contrast, the forefoot is smaller with a relatively short, though usable, thumb.
Variation in the coat color of this species has been reported; however, ambiguity in the boundaries of this species may have resulted in the misidentification of another species of the genus Arvicanthis as a color variant of A. niloticus. According to Rosevear (1969), the dorsal fur of these rats consists mostly of ringed hairs, which are dark black or brown at the base, lighter yellow, reddish-brown, or buff in the middle, and black at the tip. Short underfur, gutter hairs, and all-black guard hairs are also present and, combined with the ringed hairs, produce a "salt and pepper" effect. The ventral coat is shorter and lighter in appearance.
Range mass: 50 to 183 g.
Average mass: 118 g.
Range length: 106 to 204 mm.
Average length: 130 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Some anti-predatory behaviors have been documented for A. niloticus. Individuals typically retreat immediately down runways back to the communal burrow, possibly stopping to hide under other ground cover from avian predators. Senzota (1990) noted that when no conspecifics were present outside the burrow, individuals of this species spent a substantial amount of time in vigilant behavior at the entrances of the burrow prior to emerging. Movement by predators resulted in retreat into the burrow by A. niloticus, although mere stationary presence would not. If conspecifics were present (foraging, “playing”, or maintaining runways), individuals would readily leave the burrow.
Given the widespread range of this species and the prevalence of predation upon small mammals, particularly rodents, A. niloticus may be preyed upon by a number of carnivorous African animals. It was the primary prey of barn owls, in the Nigerian savanna and accounted for 26.5% of the biomass of these barn owls' diet in one study. Direct predation on A. niloticus by dwarf mongooses, black-backed jackals, spitting cobras, long-crested hawk-eagles, black-shouldered kites, and black-headed herons has been observed in the field.
Known Predators:
Relatively little is known about the mating structure of this species. Packer (1983) studied one colony in Tanzania and reported that the colony averaged 2.6 females and 3.1 males. Only males immigrated into the colony; new females were born in the colony and presumed not to disperse. All females successfully reproduced, and all males had descended testes, indicating the capability of breeding. Therefore, it is most likely that multiple members of an A. niloticus colony are breeding simultaneously.
Senzota (1990) studied two study sites with multiple A. niloticus colonies and indicated that colonies were mainly equally composed of males and females, with females more often outnumbering males than vice-versa. All-female and all-male colonies were also observed, but Senzota found that males were more likely to disperse than females, confirming Packer's findings.
Arvicanthis niloticus is capable of breeding year-round under highly favorable conditions. However, it usually experiences a sexual rest period beginning in March. This is during the hot dry season prior to the rainy season, and the rest period is induced at this time by long days, dry air, and high temperatures, which have an inhibitory effect on the gonads.
During the breeding season, gestation may take 18 to 25 days, averaging 23 days. Females have two equipotential ovaries and a duplex uterus. Birth weights of pups range from 3 g to 6 g, and litter sizes range from a few to 12 pups, averaging around 5 pups. Females experience a post-partum estrus and thus may be consistently pregnant and lactating, giving birth every 23 to 25 days, during the breeding season (October to March).
Young are weaned at the age of about three weeks and are considered sexually mature at 3 to 4 months. Males were observed to disperse from their natal colonies around 9 to 11 months of age.
Breeding interval: African grass rats breed every 23 to 25 days during the cold dry season in restricted habitats.
Breeding season: Mating occurs throughout the cold dry season (October to March) in restricted habitats and may occur year-round in highly suitable environments.
Range number of offspring: 4 to 12.
Average number of offspring: 5.
Range gestation period: 18 to 25 days.
Average gestation period: 23 days.
Average weaning age: 21 days.
Range time to independence: 1 to 4 months.
Average age at sexual or reproductive maturity (female): 4 months.
Average age at sexual or reproductive maturity (male): 4 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous ; post-partum estrous
Average birth mass: 4.15 g.
Average number of offspring: 5.
Average age at sexual or reproductive maturity (male)
Sex: male: 45 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 45 days.
Comprehensive examination of parental care in this species is lacking. However, mothers have been observed to defend their young prior to weaning. Lactation lasts about 21 days, and it is most likely, given preliminary data, that females rarely disperse from their natal nest, whereas males often disperse. Thus, parental care beyond lactation may occur. However, Senzota (1990) noted that wild A. niloticus did not defend their sub-adult offspring in the presence of predators but instead retreated immediately to their burrows.
Male parental care is not well-documented. Males may be kept in captivity with their mates and offspring throughout lactation but have occasionally been observed to commit infanticide, which is not uncommon in captive rodents. However, given the communal social structure of A. niloticus, it is likely that males are at the least indifferent to and at most actively parenting their offspring.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); post-independence association with parents
La aguarón africanu de la yerba (Arvicanthis niloticus) ye una especie de royedor miomorfu de la familia Muridae.
Alcuéntrase en Benín, Burkina Fasu, Burundi, República Centroafricana, Chad, República Democrática d'El Congu, Costa de Marfil, Exiptu, Eritrea, Etiopía, Gambia, Ghana, Kenia, Malaui, Mauritania, Níxer, Nixeria, Senegal, Sierra Lleona, Sudán, Sudán del Sur,Tanzania, Togu, Uganda, Yeme y Zambia.
El so hábitat natural son sabanes grebes de clima tropical o subtropical, carba húmeda, tierres de cultivu, camperes, xardinos rurales, zones urbanes, tierres de regadío y tierres agrícoles anubiertes estacionalmente.
A pesar de tratase d'una especie común, llargamente distribuyida, conócense pocos datos de la so bioloxía. Reproduzse principalmente ente los meses de xunu y payares, les femes paren ente 5 y 6 críes, 3 o 4 vegaes al añu. La mira de vida nel so mediu natural bazcuya ente 2 años y mediu y 3 años.
.La aguarón africanu de la yerba (Arvicanthis niloticus) ye una especie de royedor miomorfu de la familia Muridae.
Arvicanthis niloticus és una espècie de rosegador de la família dels múrids. Viu a Burkina Faso, Burundi, Egipte, Eritrea, Etiòpia, Gàmbia, Ghana, el Iemen, Kenya, Mauritània, el Níger, Nigèria, Oman, la República Centreafricana, la República Democràtica del Congo, Ruanda, el Senegal, el Sudan, el Sudan del Sud el Txad i Uganda. Els seus hàbitats naturals són els herbassars, els matollars i les sabanes. Es creu que no hi ha cap amenaça significativa per a la supervivència d'aquesta espècie.[1] El seu nom específic, niloticus, significa 'nilòtic' en llatí.
Arvicanthis niloticus és una espècie de rosegador de la família dels múrids. Viu a Burkina Faso, Burundi, Egipte, Eritrea, Etiòpia, Gàmbia, Ghana, el Iemen, Kenya, Mauritània, el Níger, Nigèria, Oman, la República Centreafricana, la República Democràtica del Congo, Ruanda, el Senegal, el Sudan, el Sudan del Sud el Txad i Uganda. Els seus hàbitats naturals són els herbassars, els matollars i les sabanes. Es creu que no hi ha cap amenaça significativa per a la supervivència d'aquesta espècie. El seu nom específic, niloticus, significa 'nilòtic' en llatí.
Die Nilratte oder Nil-Grasratte (Arvicanthis niloticus) ist ein Nagetier der Gattung Kusuratten, das vor allem in weiten Teilen Afrikas vorkommt.[1] Die hauptsächlich tagaktive Art frisst vorwiegend Pflanzenteile von Gräsern und Gemüse. Sie gilt in Afrika daher als landwirtschaftlicher Schädling und kann auch Krankheiten und Parasiten auf Menschen und Nutzpflanzen übertragen. In der Forschung findet die Art Verwendung als Versuchstier.
Mit einer Kopf-Rumpf-Länge von 111 bis 238 mm, einer Schwanzlänge von 92 bis 170 mm und einem Gewicht von 55 bis 258 g ist die Nilratte ein mittelgroßes kräftiges Tier von rattenähnlichem Aussehen. Sie hat 23 bis 38 mm lange Hinterfüße und 12 bis 24 mm lange Ohren. Die Haare der Oberseite sind an der Wurzel dunkelbraun, im mittleren Bereich gelbbraun und an den Spitzen schwarz. So ergibt sich eine gesprenkelte hellbraune Fellfarbe mit helleren und dunkleren Flecken. Am Hinterteil kommen oft rötliche Tönungen vor. Manche Exemplare haben einen deutlichen schwarzen Aalstrich auf dem Rücken. Die Nilratte hat hellgraues bis weißliches Fell auf der Unterseite. Ebenso ist der Schwanz oberseits dunkel gefärbt und unterseits hellbraun. An den Vorderpfoten ist der sehr kleine, jedoch nicht rudimentäre, fünfte Finger kennzeichnend. Es sind keine Rillen auf den Schneidezähnen vorhanden. Weibchen haben zwei Zitzen auf der Brust und vier im Leistenbereich.[2]
Das Verbreitungsgebiet streckt sich über die Sahelzone von Senegal und das südliche Mauretanien über Mali, Niger, das nördliche Nigeria, Tschad, den südlichen Sudan und Südsudan bis nach Äthiopien. Es setzt sich über die nordöstliche Demokratische Republik Kongo, Uganda und das westliche Kenia bis in den Norden Tansanias fort. Für weiter südlich gelegene Populationen im zentralen Tansania und in Sambia muss geprüft werden, ob diese zu dieser Art zählen. Vereinzelte Populationen sind aus dem Südwesten Jemens und aus Oman[3] sowie verschiedenen Gebieten der Sahara bekannt. Nördlich der beschriebenen Region ist dieses Nagetier in einem schmalen Bereich entlang des Nils verbreitet.[4]
Die Nilratte erreicht im äthiopischen Hochland 1600 Meter Höhe.[4] Sie bewohnt Savannen, Steppen, andere Grasflächen und besucht Hecken, Gebüschflächen sowie Ackerland. Die Art wird gelegentlich in Dörfern angetroffen, obwohl sie Gebäude meidet.[2]
Die Art baut Grasnester auf dem Boden oder in einfachen Erdhöhlen und ist vorwiegend tagaktiv. Sie legt Trampelpfade an und frisst hauptsächlich Blätter, Stängel und Samen von Gräsern sowie Gemüse. Wenn Bäume, wie die Wüstendattel (Balanites aegyptiaca), in der Trockenzeit Früchte tragen, werden diese kletternd erreicht. In der Regenzeit können bis zu 20 Prozent der Nahrung aus Insekten bestehen.[2]
Die Exemplare bilden zeitweilig Familiengruppen mit mehreren Weibchen und Männchen, sind jedoch gegenüber fremden Individuen desselben Geschlechts feindlich. Abhängig von der Verbreitung können sich Weibchen zu allen Jahreszeiten oder nur über eine begrenzte Anzahl Monate fortpflanzen. Allgemein werden in der Regenzeit die meisten Nachkommen geboren. Die durchschnittliche Anzahl der Jungtiere pro Wurf variiert zwischen 4 und 7. Sie werden nach 21 bis 23 Tagen Trächtigkeit geboren und erhalten etwa zwei Monate Muttermilch. Wild lebende Exemplare werden selten älter als ein Jahr.[2]
Zu den Fressfeinden der Nilratte zählen verschiedene Beutegreifer wie Mangusten, Schleiereulen, Gleitaare, Schopfadler, Sperberbussarde oder Echte Kobras sowie Schlangen der Gattung Psammophis.[2]
Für den Bestand der Nilratte liegen keine Gefährdungen vor. Da die Gesamtpopulation als groß eingeschätzt wird, wird die Art von der IUCN als „nicht gefährdet“ (least concern) gelistet.[4]
In weiten Teilen Afrikas gelten Nilratten als landwirtschaftlicher Schädling und es existieren Programme zur Bekämpfung der Art. Zudem wurde die Nilratte auch mit der Übertragung mehrerer Krankheiten und Parasiten auf Menschen und Nutzpflanzen in Verbindung gebracht, darunter die Beulenpest in Ägypten, die Pärchenegelart Schistosoma mansoni und das Rice Yellow Mottle Virus (RYMV). Die Übertragung des Pestbakteriums Yersinia pestis auf den Menschen erfolgt gewöhnlich über einen Zwischenwirt durch den Biss eines Rattenflohs. RYMV ist eine Virusinfektion bei Reispflanzen, von der erstmals 1966 in Kenia berichtet wurde, und kann unter anderem von Tieren wie Ratten und Käfern von Pflanze zu Pflanze übertragen werden.[5]
Aufgrund ihrer schnellen Fortpflanzungsfähigkeit, geringen Größe und Tagaktivität hat die Nilratte einen Wert als Versuchstier. Häufig verwendete Wanderratten oder Hausmäuse sind nachtaktiv, daher sind Nilratten in dieser Hinsicht in ihrem Verhalten Menschen und vielen anderen Säugetieren ähnlicher.[6] So wurden Nilratten beispielsweise zur Untersuchung des Tagesrhythmus[7] und zusammen mit Fetten Sandratten zur Untersuchung von Fettleibigkeit und Diabetes verwendet.[8]
Die Art wurde 1803 von dem französischen Zoologen Étienne Geoffroy Saint-Hilaire erstbeschrieben. Die Typuslokalität ist Ägypten. Die Nilratte zählt zur Gattung der Kusuratten, innerhalb welcher sie das größte Verbreitungsgebiet aufweist.[1]
Zu den in der Literatur verwendeten Synonymen zählen:[9]
Die Anzahl der Chromosomenarme (fundamental number) FNa liegt bei 62 oder 64. Die Form mit 62 Chromosomenarmen wurde östlich von Mali und Burkina Faso bis nach Äthiopien und Ägypten gefunden, während die andere westlich davon auftritt.[1]
Die Nilratte oder Nil-Grasratte (Arvicanthis niloticus) ist ein Nagetier der Gattung Kusuratten, das vor allem in weiten Teilen Afrikas vorkommt. Die hauptsächlich tagaktive Art frisst vorwiegend Pflanzenteile von Gräsern und Gemüse. Sie gilt in Afrika daher als landwirtschaftlicher Schädling und kann auch Krankheiten und Parasiten auf Menschen und Nutzpflanzen übertragen. In der Forschung findet die Art Verwendung als Versuchstier.
The Nile rat (Arvicanthis niloticus) is a species of rodent in the family Murinae.[2]
The species is divided into the following six subspecies.
Arvicanthis niloticus is a rodent of medium size, with the length of the head and of the body between 159 and 202 mm, the length of the tail between 125 and 173 mm, the length of the foot between 33 and 42 mm, the length of the ears between 19 and 23 mm and a weight up to 201 g.[4]
The fur is rough. The upper parts of individual hairs are yellowish with blackish tips. Long yellow or orange hairs are present on the bottom. A dorsal dark stripe more or less distinct extends from the head to the base of the tail. The ventral parts are whitish, with the base of the hairs blackish.
Areas where there are the whiskers, the eyes and a small patch behind each ear are orange. The legs are pink. The tail is shorter than the head and body, densely covered with hair, blackish above and white-yellowish below. The karyotype is 2n = 62, FN = 62-64.
It is mainly distributed in the Sahel and the sudano-zambesian Savanna belt, namely Benin, Burkina Faso, Burundi, Central African Republic, Chad, Democratic Republic of the Congo, Ivory Coast, Eritrea, Ethiopia,[5] Gambia, Ghana, Kenya, Malawi, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, Somalia, Sudan, Tanzania, Togo, Uganda, and Zambia. Populations also occur in Algeria, Egypt, and Yemen.
Despite its wide distribution and commonness, little is known about the biology and actual occurrence of the species. It reproduces mainly between June and November. The females give birth to 5-6 small cubs at least 3-4 times a year. Life expectancy in the wild is 2.5–3 years.
Its natural habitats are dry savanna, moist savanna, subtropical or tropical moist shrubland, arable land,[6] pastureland, rural gardens, urban areas, irrigated land, and seasonally flooded agricultural land.
The Nile rat has gained traction as a useful nutritional model to study Type 2 Diabetes (T2DM). The Nile Rat gets Metabolic Syndrome that develops into diet-induced Type 2 Diabetes that is similar to human T2DM: insulin resistance, hyperinsulinemia, increased body fat, hypertension, elevated Triglycerides with decreased High-Density Lipoproteins, and eventually hyperglycemia and beta cell failure resulting in depressed insulin and end-stage diabetes that includes severe ketosis. The beta cell failure follows the same course as the five-stage decline documented in humans with T2DM.[7]
La rata africana de la hierba (Arvicanthis niloticus) es una especie de roedor miomorfo de la familia Muridae.
Se encuentra en Benín, Burkina Faso, Burundi, República Centroafricana, Chad, República Democrática del Congo, Costa de Marfil, Egipto, Eritrea, Etiopía, Gambia, Ghana, Kenia, Malaui, Mauritania, Níger, Nigeria, Senegal, Sierra Leona, Sudán, Sudán del Sur, Tanzania, Togo, Uganda, Yemen y Zambia.
Su hábitat natural son sabanas áridas de clima tropical o subtropical, matorral húmedo, tierras de cultivo, pastos, jardines rurales, zonas urbanas, tierras de regadío y tierras agrícolas inundadas estacionalmente.
A pesar de tratarse de una especie común, ampliamente distribuida, se conocen pocos datos de su biología. Se reproduce principalmente entre los meses de junio y noviembre, las hembras paren entre 5 y 6 crías, 3 o 4 veces al año. La expectativa de vida en su medio natural oscila entre 2 años y medio y 3 años.
La rata africana de la hierba (Arvicanthis niloticus) es una especie de roedor miomorfo de la familia Muridae.
Arvicanthis niloticus Arvicanthis generoko animalia da. Karraskarien barruko Murinae azpifamilia eta Muridae familian sailkatuta dago.
Arvicanthis niloticus Arvicanthis generoko animalia da. Karraskarien barruko Murinae azpifamilia eta Muridae familian sailkatuta dago.
Arvicanthis niloticus (rat du Nil ou rat roussard) est une espèce de mammifères de la famille des Muridae, d'origine africaine.
Cette espèce de rat est commune en Afrique, notamment dans la vallée du Nil et dans les pays du Sahel.
Il topo del Nilo[2] (Arvicanthis niloticus E.Geoffroy, 1803) è un roditore della famiglia dei Muridi diffuso nell'Africa subsahariana.[1][3]
Roditore di medie dimensioni, con la lunghezza della testa e del corpo tra 159 e 202 mm, la lunghezza della coda tra 125 e 173 mm, la lunghezza del piede tra 33 e 42 mm, la lunghezza delle orecchie tra 19 e 23 mm e un peso fino a 201,2 g.[4]
La pelliccia è ruvida. Le parti superiori sono giallastre; le punte dei singoli peli nerastre danno un aspetto generale brizzolato. Lunghi peli interamente giallastri o arancioni sono presenti sul fondoschiena. Una striscia dorsale scura più o meno distinta si estende dal capo alla base della coda. Le parti ventrali sono biancastre, con la base dei peli nerastra. Le zone dove sorgono le vibrisse, intorno agli occhi e una piccola macchia dietro ogni orecchio sono color arancione. Le zampe sono rosa. La coda è più corta della testa e del corpo, densamente ricoperta di peli, i quali nascondono quasi completamente le scaglie, nerastra sopra e bianco-giallastra sotto. Il cariotipo è 2n=62 FN=62-64.
È una specie terricola e attiva sia di giorno che di notte. Costruisce tane superficiali, lunghe e fornite di numerose entrate, le quali non vengono mai chiuse. All'interno solitamente sono presenti un maschio ed una femmina, tranne che nei periodi invernali, quando per riscaldarsi si associano più individui. Vengono utilizzate principalmente come rifugi temporanei o come luoghi dove nutrirsi. Solitamente si trova lungo percorsi sulle sponde dei canali od altri ambienti favorevoli.
Si nutre di granaglie, vegetali e frutta. Viene considerata una piaga per gli agricoltori, in particolare per le piantagioni di canna da zucchero, la quale base viene spesso rossicchiata.
Si riproduce principalmente tra giugno e novembre. Le femmine danno alla luce 5-6 piccoli per almeno 3-4 volte l'anno. L'aspettativa di vita allo stato selvatico è di 2,5-3 anni.
Questa specie è diffusa lungo il Nilo e nella fascia subsahariana dal Senegal fino all'Etiopia a est e lo Zambia a sud. È presente anche in tre aree montane isolate del Sahara.
La popolazione dello Yemen sud-occidentale è stata probabilmente introdotta.
Vive nelle Savane, distese erbose e di arbusti. È molto comune vicino agli insediamenti umani. In Etiopia è stato osservato fino a 1.600 metri di altitudine.
Sono state riconosciute 6 sottospecie[5]:
La IUCN Red List, considerato il vasto areale, la tolleranza al degrado del proprio habitat e la popolazione numerosa, classifica A.niloticus come specie a rischio minimo (LC).[1]
Il topo del Nilo (Arvicanthis niloticus E.Geoffroy, 1803) è un roditore della famiglia dei Muridi diffuso nell'Africa subsahariana.
De koesoegrasrat (Arvicanthis niloticus) is een knaagdier uit het geslacht Arvicanthis dat voorkomt in grote delen van Afrika. Deze soort komt in West-Afrika voor in de droge steppen van de noordelijke Sahel, ten noorden van de verspreiding van A. ansorgei, van Senegal ten noorden van de Gambia in het westen tot Soedan en Ethiopië onder 610 m hoogte, met een uitbreiding naar het noorden in het Nijldal van Egypte. Verder naar het zuiden komt de soort voor van Oost-Congo-Kinshasa en Oeganda tot West-Tanzania, Oost-Zambia en Noord-Malawi. Er is een geïsoleerde populatie in Zuidwest-Jemen en West-Oman op het Arabisch schiereiland. De soort komt mogelijk in grote delen van de Sahara voor in iets nattere gebieden dan de echte woestijn, hoewel hij daar alleen in Hoggar (Zuidoost-Algerije) is gevonden. Verschillende vormen worden soms als aparte soorten gezien: naso uit Arabië, dembeensis uit Ethiopië en omliggende gebieden, en testicularis uit de zuidelijke delen van de verspreiding. Het karyotype bedraagt 2n=62, FNa=62-66. FNa=62 (bekend als "ANI-1a) komt voor in het grootste deel van het verspreidingsgebied, FNa=64 ten westen van Mali, en FNa=66 in Ethiopië. Alle andere Arvicanthis-soorten zijn in vroegere classificaties tot A. niloticus gerekend, maar zelfs nu zes soorten van deze soort zijn afgesplitst zijn de grenzen tussen de soorten soms nog onduidelijk. Zo behoren de meest zuidelijke populaties mogelijk niet tot deze soort.[2]
Bronnen, noten en/of referenties
Multimedia w Wikimedia Commons Kusu nilowy (Arvicanthis niloticus) – gatunek ssaka z rodziny myszowatych. Tradycyjnie uważa się, że występuje w Dolinie Nilu i większości saharyjskiej części Afryki, ale brak jest dokładniejszych badań, więc obszar występowania może być dużo mniejszy.
Długość ciała wynosi 10–20 cm, masa ciała 50-180 g, samce nieco większe od samic. Pokryty krótkimi włosami ogon ma długość ok. 10 cm. Głowa jest okrągła, z dużymi oczami i krótkim pyskiem. Sierść przybiera kolor od brązowego po żółty.
Żyje w grupach na terenach porośniętych krzewami i drzewami. Samce przemieszczają się pomiędzy grupami, samice całe życie spędzają w jednym stadzie. Żyją w norach, na głębokości ok. 20 cm pod ziemią. Charakterystyczne dla nich jest tworzenie „dróg” w trawie – specjalnych ścieżek, które zwierzęta utrzymują w czystości, sprzątając z nich resztki roślin. Żywią się głównie roślinnością, choć czasami zjadają bezkręgowce.
Zwierzęta rozmnażają się przez cały rok. Samica po ok. 25 dniach ciąży rodzi 4-12 młodych (zwykle 5). Samice mogą podczas karmienia zajść w ciążę, co oznacza, że są zdolne wychować jeden miot co miesiąc. Młode są karmione mlekiem przez ok. 3 tygodnie, osiągają dojrzałość płciową w wieku 4-5 miesięcy. Zwierzęta te w niewoli żyją średnio 2 lata, nie wiadomo, ile wynosi średnia długość życia na wolności, ale prawdopodobnie nie dożywają roku.
Kusu nilowy (Arvicanthis niloticus) – gatunek ssaka z rodziny myszowatych. Tradycyjnie uważa się, że występuje w Dolinie Nilu i większości saharyjskiej części Afryki, ale brak jest dokładniejszych badań, więc obszar występowania może być dużo mniejszy.
O Arvicanthis niloticus é uma espécie de roedor da família Muridae.
Pode ser encontrada nos seguintes países: Benin, Burkina Faso, Burundi, República Centro-Africana, Chade, República Democrática do Congo, Costa do Marfim, Egito, Eritréia, Etiópia, Gâmbia, Gana, Quênia, Malawi, Mauritânia, Níger, Nigéria, Arábia Saudita, Senegal, Serra Leoa, Sudão, Tanzânia, Togo, Uganda e Zâmbia.
O Arvicanthis niloticus é uma espécie de roedor da família Muridae.
Pode ser encontrada nos seguintes países: Benin, Burkina Faso, Burundi, República Centro-Africana, Chade, República Democrática do Congo, Costa do Marfim, Egito, Eritréia, Etiópia, Gâmbia, Gana, Quênia, Malawi, Mauritânia, Níger, Nigéria, Arábia Saudita, Senegal, Serra Leoa, Sudão, Tanzânia, Togo, Uganda e Zâmbia.
Arvicanthis niloticus[2] är en däggdjursart som först beskrevs av Anselme Gaëtan Desmarest 1822.[3] Enligt Wilson & Reeder (2005) och IUCN beskrevs arten av É. Geoffroy 1803.[4][1] Arvicanthis niloticus ingår i släktet gräsråttor, och familjen råttdjur.[5][3] IUCN kategoriserar arten globalt som livskraftig.[1] Inga underarter finns listade i Catalogue of Life.[5]
Arten når en kroppslängd (huvud och bål) av 106 till 204 mm, en svanslängd av cirka 100 m och en vikt mellan 50 och 183 g. Honor är allmänt lite lättare än hanar. Pälsfärgen varierar mellan olika populationer och ofta förväxlas Arvicanthis niloticus med andra arter av samma släkte. Håren på ovansidan är nära huden mörkbrun till svart, i mitten rödbrun till gulbrun och vid spetsen åter svart. Pälsen har därför ett prickigt utseende. Undersidan är allmänt ljusare. Huvudet kännetecknas av stora runda öron som är glest täcka med hår. De fina håren på svansen är nästan osynliga. På artens framtänder finns inga rännor.[6]
Detta råttdjur förekommer i flera från varandra skilda områden i Afrika. Den största populationen finns i Sahelzonen. Arten når antagligen så långt söderut som Zambia. I bergstrakter når Arvicanthis niloticus upp till 1600 meter över havet. Habitatet utgörs av savanner och andra gräsmarker samt buskskogar. Djuret uppsöker även jordbruksmark och platser nära byar.[1]
Det är inte utrett vilka dagstider arten föredrar. Olika studier hade olika resultat. Arvicanthis niloticus skapar komplexa underjordiska bon som ligger upp till 20 cm under markytan. Individerna gör dessutom stigar genom att trampa ner växtligheten eller genom att bita av stjälkar och gräs. Denna gnagare äter olika växtdelar som blad, örter, frön, bark och grönsaker. Födan kompletteras med några ryggradslösa djur.[6]
Enligt en studie från Tanzania bildas flockar med cirka tre hanar och tre honor samt deras ungar. Ibland förekommer grupper med endast honor eller endast hanar. Vanligen lämnar hanarna sin ursprungliga flock när de blir könsmogna.[6]
Honor kan ha flera kullar per år. Bara under den torra årstiden sker ingen parning. Efter 18 till 25 dagar dräktighet föds upp till 12 ungar per kull (oftast 5). Ungarna väger vid födelsen 3 till 6 g och de diar sin mor ungefär tre veckor. Tre till fyra månader efter födelsen blir ungarna könsmogna.[6]
Arten har flera naturliga fiender som ugglor, falkfåglar, större ormar och rovdjur. Uppskattningsvis lever de flesta vilda individer 10 månader. I fångenskap kan Arvicanthis niloticus leva ett eller två år. Den äldsta kända individen levde 6 år och 8 månader.[6]
Wikimedia Commons har media som rör Arvicanthis niloticus.
Wikispecies har information om Arvicanthis niloticus.
Arvicanthis niloticus är en däggdjursart som först beskrevs av Anselme Gaëtan Desmarest 1822. Enligt Wilson & Reeder (2005) och IUCN beskrevs arten av É. Geoffroy 1803. Arvicanthis niloticus ingår i släktet gräsråttor, och familjen råttdjur. IUCN kategoriserar arten globalt som livskraftig. Inga underarter finns listade i Catalogue of Life.
Довжина тіла 10-20 см, маса 50-180 гр, самці трохи більші самиць. Покритий коротким волоссям хвіст має довжину близько 10 см. Голова кругла з великими очима і короткою мордою. Волосся займає спектр кольорів від коричневого по жовтий.
Країни проживання: Буркіна-Фасо, Бурунді, Центральноафриканська Республіка, Чад, Демократична Республіка Конго, Кот-д'Івуар, Єгипет, Еритрея, Ефіопія, Гамбія, Гана, Кенія, Малаві, Мавританія, Нігер, Нігерія, Сенегал, Сьєрра-Леоне, Судан, Уганда, Ємен. В Ефіопії знайдений до 1600 м над рівнем моря. Полюбляє луки, савани і чагарники. Дуже часто знаходиться близько до сіл та інших модифікованих областей.
Живе в групами в заростях чагарника і рідколіссі. Самці переміщаються між групами, самиці проводять все своє життя в одній групі. Живуть у норах, на глибині близько 20 см під землею. Характеристикою є створення "доріг" в траві - спеціальні доріжки, що тварини утримуватися в чистоті, прибираючи них рослинні залишки. Вони їдять в основному рослини, хоча іноді безхребетних.
Тварини розмножуються протягом усього року. Самиці приблизно через 25 день вагітності, народжують 4-12 мишенят (зазвичай 5). Молодь харчується молоком близько трьох тижнів й досягає статевої зрілості у віці 4-5 місяців. Ці тварини в неволі живуть в середньому два роки, середня тривалість життя в дикій природі, ймовірно, менше року.
Arvicanthis niloticus là một loài động vật có vú trong họ Chuột, bộ Gặm nhấm. Loài này được É. Geoffroy mô tả năm 1803.[1]
Arvicanthis niloticus là một loài động vật có vú trong họ Chuột, bộ Gặm nhấm. Loài này được É. Geoffroy mô tả năm 1803.
Arvicanthis niloticus (E. Geoffroy, 1803)
Синонимы
Травяная мышь[1][2] , или нилотская травяная мышь[3] (лат. Arvicanthis niloticus) — вид рода травяные мыши подсемейства мышиные. Травоядная мышь ведёт дневной образ жизни. Широкораспространённый африканский вид, единственный вид рода, который содержится в неволе в качестве домашнего питомца. В Египте этот вид относят к сельскохозяйственным вредителям.
Обитает к югу от Сахары, встречается также на Аравийском полуострове, куда, видимо, была привнесена человеком. Широко распространена в африканской саванне от Сенегала до Судана и Эфиопии, откуда ареал простирается на юг, включая Уганду и Кению. Кроме этого, обитает в долине Нила, где в основном ареал ограничен узкой полосой заливаемой равнины. Обнаружена также в трёх изолированных горных цепях Сахары.
Естественное местообитание травяной мыши — сухая и влажная саванны, субтропические и тропические влажные кустарниковые заросли, орошаемые земли, пастбища, а также сады, города, осушенные земли и сельскохозяйственные земли, подвергающиеся сезонным наводнениям.
Будучи в отличие от большинства грызунов дневным животным, травяная мышь служит объектом исследования циркадных ритмов[4]. При питании обычной лабораторной диетой, используемой для лабораторных мышей, травяные мыши развивают системную патологию схожую с метаболическим синдромом человека. У них спонтанно развивается ожирение, гипергликемия и гипертензия[5].
Куактье, который поспешно приблизился к книге, не утерпел и воскликнул:
— Помилуйте! Да что же тут такого страшного? Glossa in epistolas D. Pauli. Norimbergae, Antonius Koburger, 1474. Это вещь не новая. Это сочинение Пьера Ломбара, прозванного «Мастером сентенций». Может быть, эта книга страшит вас тем, что она печатная?
— Вот именно, — ответил Клод. Погрузившись в глубокое раздумье, он стоял у стола, держа согнутый указательный палец на фолианте, оттиснутом на знаменитых нюрнбергских печатных станках. Затем он произнёс следующие загадочные слова:
— Увы! Увы! Малое берёт верх над великим; один-единственный зуб осиливает целую толщу. Нильская крыса убивает крокодила, меч-рыба убивает кита, книга убьёт здание!
Монастырский колокол дал сигнал о тушении огня в ту минуту, когда Жак Куактье повторял на ухо своему спутнику свой неизменный припев: «Это сумасшедший». На этот раз и спутник ответил: «Похоже на то!»
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|month= (справка) |month= (справка) Травяная мышь , или нилотская травяная мышь (лат. Arvicanthis niloticus) — вид рода травяные мыши подсемейства мышиные. Травоядная мышь ведёт дневной образ жизни. Широкораспространённый африканский вид, единственный вид рода, который содержится в неволе в качестве домашнего питомца. В Египте этот вид относят к сельскохозяйственным вредителям.
아프리카풀밭쥐(Arvicanthis niloticus)는 쥐과에 속하는 설치류의 일종이다.[2][3]
아프리카풀밭쥐는 중형 크기의 설치류로 머리부터 몸까지 길이는 159~202mm, 꼬리 길이는 125~173mm, 발 길이는 33~42mm이다. 귀 길이는 19~23mm이고, 몸무게는 최대 201g이다.[4]
털은 거칠다. 상체의 털은 끝이 검고 누르스름하다. 아랫쪽은 노랗거나 오렌지색의 긴 털이 나 있다. 등 쪽에는 진한 줄무늬가 머리부터 꼬리가 있는 엉덩이 부분까지 이어져 있다. 복부 쪽은 희끄무레한 색을 띠며, 피부 쪽은 검다.
수염이 있는 곳, 눈과 각 귀 뒷쪽에는 오렌지색의 작은 반점이 나 있다. 다리는 분홍색이다. 꼬리 길이가 머리부터 몸까지 길이보다 짧고, 윗면은 검고 아랫면은 희고 노란 털이 무성하게 덮여 있다. 핵형은 2n = 62, FN = 62-64이다.
6종의 아종이 알려져 있다.
사헬과 수단 사바나 지대에 주로 분포하며, 베넹과 부르키나 파소, 부룬디, 중앙아프리카공화국, 차드, 콩고민주공화국, 코트디부아르, 에리트레아, 에티오피아, 감비아, 가나, 케냐, 말라위, 모리타니, 니제르, 나이지리아, 세네갈, 시에라리온, 수단, 탄자니아, 토고, 우간다, 잠비아에서 발견된다. 알제리와 이집트, 예멘에서 발견되기도 한다.
넓은 분포 지역에서 흔하게 발견되지만, 생태와 습성을 잘 알려져 있지 않다. 6월과 11월 사이에 주로 번식을 한다. 암컷은 일년에 3~4번, 5~6마리의 새끼를 낳는다. 야생에서 수명은 2.5~3년 정도이다.
자연 서식지는 건조 사바나 지역과 습윤 사바나 지역, 아열대 또는 열대 기후 지역의 습윤 관목 지대와 경작지, 목초지, 시골과 도시 지역, 관개 토지, 계절성 홍수림 농경지 등이다.
