5018 x 3343 px | 42,5 x 28,3 cm | 16,7 x 11,1 inches | 300dpi
Data acquisizione:
12 novembre 2010
Ubicazione:
Norfolk England UK
Altre informazioni:
The brown rat, common rat, street rat, sewer rat, Hanover rat, Norway rat, brown Norway rat, Norwegian rat, or wharf rat (Rattus norvegicus) is one of the best known and most common. It is a brown or grey rodent with a body up to 10 in long, and a similar tail length; the male weighs on average 12 oz and the female 9 oz. Thought to have originated in northern China, this rodent has now spread to all continents except Antarctica, and is the dominant rat in Europe and much of North America—making it by at least this particular definition the most "successful" mammal on the planet after humans.Indeed, with rare exceptions, the brown rat lives wherever humans live, particularly in urban areas. The brown rat can breed throughout the year if conditions are suitable, with a female producing up to five litters a year. The gestation period is only 21 days, and litters can number up to 14, although seven is common. They reach sexual maturity in about five weeks. The maximum life span is up to three years, although most barely manage one. A yearly mortality rate of 95% is estimated.
