Brown Rat

Common Name: Brown Rat / Sewer Rat / Norway Rat

Family Name: Muridae

Scientific Name: Rattus norvegicus

Status: Introduced, Not Protected

Average Size: 18cm, not including an 18cm tail

Average Lifespan: 2 years

Litter: 5

Gestation: 21 to 23 days

Weaned: 21 days

Background: Originating northern China , arriving with European settlers in the late 18th century

Breeding: Polygynous mating system, can produce 3 to 6 litters per year.

Impacts: Brown rat’s urine can spread diseases like Hantavirus (Rat-bite fever) and other potential disease transmission, predation on small birds, lizards, small native mammals, rodents and amphibians, competition for resources, potentially leading to extinctions and declines in biodiversity

Feeding: Omnivorous, preferring fruit, grains, and other plant materials, can also eat insects or other invertebrates

Brown rats are larger than black rats and have a shorter tail relative to their body length. Black rats are slender and have a longer tail