Brown Rat - Naming and Etymology

Naming and Etymology

Originally called the "Hanover rat" by people wishing to link problems in 18th century England with the House of Hanover, it is not known for certain why the brown rat is named Rattus norvegicus (Norwegian rat), as it did not originate from Norway. However, the English naturalist John Berkenhout, author of the 1769 book Outlines of the Natural History of Great Britain, is most likely responsible for popularizing the misnomer. Berkenhout gave the brown rat the binomial name Rattus norvegicus, believing it had migrated to England from Norwegian ships in 1728, although no brown rat had entered Norway at that time.

By the early to middle part of the 19th century, British academics were aware that the brown rat was not native to Norway, hypothesizing (incorrectly) that it may have come from Ireland, Gibraltar or across the English Channel with William the Conqueror. As early as 1850, however, a more correct understanding of the rat's origins was beginning to develop. The British novelist Charles Dickens acknowledged the misnomer in the 2 June 1888 edition of his weekly journal, All the Year Round, writing:

"Now there is a mystery about the native country of the best known species of rat, the common brown rat. It is frequently called, in books and otherwise, the 'Norway rat', and it is said to have been imported into this country in a ship-load of timber from Norway. Against this hypothesis stands the fact that when the brown rat had become common in this country, it was unknown in Norway, although there was a small animal like a rat, but really a lemming, which made its home there."

Academics began to understand the origins and corrected etymology of the brown rat towards the end of the 19th century, as seen in the 1895 text Natural History by American scholar Alfred Henry Miles:

"The brown rat is the species common in England, and best known throughout the world. It is said to have travelled from Persia to England less than two hundred years ago and to have spread from thence to other countries visited by English ships."

Though the assumptions surrounding this species' origins were not yet entirely accurate, by the 20th century, it was established among naturalists that the brown rat did not originate in Norway, rather the species came from central Asia and (likely) China. Despite this, this species' common name of "Norway rat" is still in use today.