The Black Rat

Rattus rattus

The black rat (Rattus rattus), also called ship rat or house rat is a common long-tailed rodent of the genus Rattus of the Murinae subfamily.

Despite its name, the color of the black rat may vary. Indeed, its fur fluctuates from black to hazelnut while the underside of its body is lighter in color. Its length generally ranges from 15 to 20 cm, to which is added an elongated tail of 20 cm, always longer than the body. Compared to the brown rat, it is a mediocre swimmer. However, it is a much better climber who willingly tries to escape from the top.

It is a nocturnal and omnivorous animal, which prefers seeds for consumption or possibly fruits. It is very suspicious (more than the brown rat) and can take a long time to start feeding on a new food. If an individual fells sick after ingesting a new food, the Alpha (dominant male) may urinate on the food so that no other rat of the group consumes it (code for the group). The nests of black rats are generally located in high spaces, in dry areas and in dark corners.

On La Réunion, they breed throughout the year. The female rats can have 3 to 6 litters per year counting up to 10 rats each. They have the ability to regulate their fertility and produce only one litter per year when food is scarce. The avearge life span of Rattus rattus in social groups that cn reach up to 60 individuals is 2 to 3 years.

The black rat can rarely be tamed. Actually, the contact of a wild species with man remains delicate. Being a vector of diseases such as leptospirosis, the black rat is often subject to collective control campaigns in agricultural and urban areas. Eradication operations are also carried out in natural environments with the aim of protecting native species or for ecological restoration. Usually these operations involve chemical techniques (poisoning) or methods combining the successive use of trapping and chemical control.

The black rat represents a real and critical threat to the Gecko Vert de Bourbon and its eggs. In addition, it does not hesitate to attack fruits of endemic and native species on ground and on trees.

Photo Credit : LIFE+ COREXERUN