Nile or African Grass Rat
Arvicanthis (spp) ranges throughout most of Africa, with the greatest concentration in East Africa as well as along the Nile river. Arvicanthis prefers to live in savanna grasslands; however, it can also survive in a desert climate, provided that the area receives some form of regular irrigation (natural or manmade).
Nile or African grass rat
Arvicanthis niloticus is a vole-like rat with a stout body, coarse fur and short legs. Its fifth toe is reduced but usable. It ranges in color from buff to olive brown to dark gray-brown, sometimes with a dorsal stripe. The fur on the belly is usually lighter in color than that on the rest of the body. The fur appears grizzled due the dark tips of the ends of the hairs.
Reproduction
Studies have demonstrated that the polyestrous Arvicanthis breeds throughout the year. It is a spontaneous ovulator and has an 18 day gestation period (approximately). Females usually bear 5-6 young, each weighing from 3-6 grams; these are weaned at about 3 weeks. The young reach maturity at around 3 or 4 months of age and can live up to 6 years (reported in a captive animal).
Behavior
A. niloticus is a gregarious species, residing in burrows under grass patches with varying numbers of conspecifics, depending on the overall population density (which can range from scattered, small colonies of a handful of animals to situations in which animals are almost literally underfoot). The animals use “runways” to travel from grazing patch to grazing patch and back to the colony. These runways take advantage of natural formations of the ground and are smooth, dirt trails that resemble miniature hiking paths. The rodents will clear the paths of small obstructions and keep the surrounding grass clipped out of the way.
Arvicanthis is agile and quick despite its slightly pudgy appearance and seems to be able to return to its home range when released within a quarter-mile of where it is captured. Home range size is variable, ranging from 37 to 86m for males, and 38 to 47m for females, depending on whether the animals were studied during high density periods or low density periods, respectively. Arvicanthis is a diurnal creature and is most active in the morning, before the sun is overhead, but also has periods of evening activity and some activity during the night hours.
Food Habits
The Nile rat’s food preferences are almost exclusively vegetarian. It consumes mostly grains, seeds and grass shoots. It can, however, subsist on other fare, such as insects and fruits. In captivity they should be offered a complete diet of rodent lab blocks, and rat or mouse mix, with bits of fruit or veggies regularly. Cheerios or wheat bread are great treats, in small quantities. Do NOT feed chocolate, fried foods, salted foods, candy or junk food! They may enjoy crickets and mealworms if they are captive bred, never feed wild insects as they may carry parasites.
Vitamins, like Nutri-Cal are a good addition to their diet, and added calcium during nursing and growth due to demands on their systems at those times, but take care not to overdo it. Water bottles should be used to proved constant, clean water. Ceramic or stoneware food dishes work well for keeping seeds or fresh foods off the floor, and a wire mesh hopper that allows them to eat the lab blocks through without extra waste.
