Black rat

Facts

IUCN LEAST CONCERN (LC)

Facts about this animal

The black rat is one of the larger Muridae species with a head-body length of 14-23 cm, a tail of 17-28 cm and a body-weight pf 75-230 g. It is smaller and more slender, and has a more pointed muzzle, than the brown rat. The ears are relatively long. The naked tail is usually longer than head and body, and has 200-260 rings. The female has 10 teats.

The glossy fur is not very dense. Its colour is variable, either greyish-black, greyish-brown with a grey belly, or greyish-brown with a white belly.

Black rats are predominantly nocturnal. They are good climbers and have their nests either on trees or underground in caves. They are social animals, living in groups consisting of a dominant male and several adult females with their offspring, and territorial, defending their group territory against other groups.

After a gestation period of 21 days, the female gives birth to usually 5-7 young. Ander favourable conditions reproduction is not seasonal, and a female may have 3-5 litters per year. In the wild longevity is hardly more than one year.

Black rats are omnivorous, although plant material accounts for the greater part of their diet. In addition to fruit, grains, shoots etc. they also feed on invertebrates and occasionally small vertebrates or carrion.

Did you know?
That the Black Rat has directly caused or contributed to the extinction of many species of wildlife including birds, small mammals, reptiles, invertebrates, and plants, especially on islands?

Factsheet
Class	MAMMALIA
Order	RODENTIA
Suborder	MYOMORPHA
Family	MURIDAE
Name (Scientific)	Rattus rattus
Name (English)	Black rat
Name (French)	Rat noir
Name (German)	Hausratte, Dachratte
Name (Spanish)	Rata negra, Rata de barco, Rata del tejado
Local names	Czech: Krysa Dutch: Zwarte rat Estonian: Kodurott Hungarian: Házi patkány Italian: Ratto nero Polish: Szczur sniady Portuguese: Rato-preto Romansh: Ratun nair Swedish: Svartråtta
CITES Status	Not listed
CMS Status	Not listed

Photo Copyright by
Vladimír Motyčka

Distribution

Distribution
Range	Widely distributed around the globe.
Habitat	Widespread in forest and woodlands as well as being able to live in and around buildings
Wild population	Unknown, but widely distributed (Red List 2011).
Zoo population	486 reported to ISIS (2008) but this species is often kept as a pet animal and used in medical researches.

In the Zoo

How this animal should be transported

For air transport, Container Note 81 of the IATA Live Animals Regulations should be followed.

Find this animal on ZooLex

Photo Copyright by
Vladimír Motyčka

Why do zoos keep this animal

If kept in a nocturnal house, black rats make an interesting exhibit. Keeping them is of educational value as it allows to tell stories about the extermination of islnd species due to introduced rats, and about the role the black rat has played, and still plays, in disease transmission.

How this animal should be kept

Black rats are social animals and must be kept in pairs or, preferably, groups containing one adult male and several adult females with their offspring.

The biggest concern in any grouping of black rats is overcrowding. If there are too many rats in too small an enclosure, dominance fights can quickly become fatal. If fights, or bite marks or pulled out hair on the smaller members of the group are observed, the entire group should be moved to a larger enclosure, or some of the animals should be removed.

Black rats are usually kept indoors in terrarium-type enclosures. Behind the scene, black rats may be kept in smaller terrariums, exhibits, however, should have a minimum surface of about 2 m². Materials used for the construction of the exhibit should be resistant to the gnawing teeth of the rats in order to avoid escapes. The enclosure should be well structured - it could simulate a kitchen, store or warehouse - and must contain sleeping dens and hiding opportunities. Hay and straw should be provided as nesting material. The floor should be covered with a suitable substrate or should consist of a solid grate. There should be several feeding bowls. Water should be provided in a drinking bottle positioned in a way that it cannot be chewed by the mice. A minimum temperature of 15ºC should be maintained, in places higher (radiators). The day phase should be around 12 hours.

The diet consists of cereals and other seeds supplemented with fruit and vegetables (tomatoes should not be offered because they contain oxalic acid which may damage the rat’s kidneys). In addition, black rats need animal protein, e.g. shrimp pellets, live meal worms, snails etc.