The Black Rat is one of the most notorious animals in history, it is also known as the Asian Black Rat, Ship Rat and Old English Rat and has a long association with the spread of Bubonic plague which was actually spread by flees carried by the rats, although they are prone to many other diseases including typhus, and toxoplasmosis.
The Black rat is a long tailed rodent which can be found in several colours normally black to light brown with a lighter belly fur but can be found totally black furred. It ranges from 15 to 20cm long from nose to end of body with a tail as long again as the body, weighing in at around 200g. They tend to be slimmer than the more common brown rat with larger ears and tail and better eyesight than Brown Rats.
In the UK they tend to breed from spring to the end of autumn and in good conditions produce up to 5 litters of around 8 young in a year. Gestation is around 24 days and weaning takes only 3-4 weeks which means populations can grow very rapidly. In other areas with the right conditions a single female can produce 6 litters of 10 young meaning 60 new rats per year per female, although when food is scarce the female will only produce 1 litter, life expectancy is around 3 years. Male dominated groups of up to 60 rats can form and although dominated by the males’ fights among females are common.
Black rats like omnivores but have a liking for grains and a greater tendency to eat fruit than the Brown rat. They aren’t as good swimmers as Brown rats but are far better climbers which maybe due to them originally evolving in the jungles of tropical Asia. They are nocturnal and away from urban areas they will eat small forest birds, invertebrates and even small reptiles.
The Black rat spread from Asia in Roman times reaching Europe in the 6th century and then being spread aboard European ships across the world, hence its name the ship rat. In some countries such as New Zealand which lacked native rodents they have had a big impact on the local ecosystem. They have adapted to living along side humans as the wastefulness of humans provides a ready source of food, although they still tend to be concentrated in coastal areas and have been driven out of cooler regions by the Brown rat.Surprisingly Black Rats are one of the UK’s rarest mammals as the Brown Rat population has grown. Black rats can still be found in some UK port cities such as London and Liverpool and in isolated island colonies such as on the islands of the Inner Hebrides and on Lundy Island. Due to the diseases wild populations can carry and spread to humans they are still subject to pest control.