There are 2 species of rat in the UK, the black rat (Rattus rattus) which is now quite rare and the Norwegian/brown rat (Rattus norvegicus). The photos below are of a large brown rat in Staffordshire, England. Full credit for these pictures must go to my uncle, who shall remain anonymous because as far as I know he doesn't do social media.
What has it got?
Rats tend to thrive in urban environments because they are opportunistic omnivores. They are not pre-programmed to eat certain foods and so each individual will adapt and learn what to eat in its own local environment. As the cosmologist Stephen Hawking said, "intelligence is the ability to adapt to change." By this measure, rats are quite bright. It comes as no wonder that they are studied so much.
Rats' adaptability is reflected in their food preferences. Though typically thought of as scavengers, they are known to kill and eat a wide variety of small animals, including invertebrates (Strecker et al. 1962), other rodents (Hsuchou et al. 2002), bats (Villa 1982), birds (Atkinson 1985, Heather et al. 2002, Moira et al. 1999), amphibians and reptiles (Newman 1986, Whitaker 1978).
The adaptability and effectiveness of the rat's predatory behavior are some of the reasons rats are a major conservation concern: when rats invade and establish themselves in a new habitat, they prey on indigenous wildlife. Rats may drastically reduce the numbers and reproductive success of local species, and may drive some species to extinction, as can be seen by the problems they cause with small marsupials and flightless birds in Australasia.
After detecting their prey rats catch it then make the kill with a bite to the head. They then manipulated it or -like the frog shown above- remove it to somewhere safe to eat. They will also cache food in times of abundance.
A predator in action.
Hope you liked these pictures. It seems there's a bit more to the lives of common rat than we would assume.
References:
Atkinson, I. A. E. 1985. The spread of commensal species of Rattus to oceanic islands and their effects on island avifaunas. ICBP Technical Publication No. 3: 35-81.
Hanson, A. 2004. Predatory Behaviour. http://www.ratbehavior.org/norway_rat_ethogram.htm
Heather L. Major and Ian L. Jones 2002. Impacts of the Norway Rat on the auklet breeding colony at Sirius Point, Kiska Island, Alaska in 2002
Hsuchou H, Ho YJ, Shui HA, Tai MY, Chen KH, Tsai YF. 2002. Effects of incisor-cutting on muricidal behavior induced by olfactory bulbectomy in rats. Physiol Behav. 76(4-5):669-75.
Moira J.F. Lemon and Anthony J. Gaston. 1999. Trends in Ancient Murrelet populations since 1980. Bird trends: A report on results of national ornithological surveys in Canada. Migratory birds conservation. Canadian wildlife service.
Newman, D.G. 1986. Can tuatara and mice co-exist? The status of the tuatara, Sphenodon punctatus (Reptilia: Rhynchocephalia), on the Whangamata Islands. In: The Offshore Islands of Northern New Zealand, edited by A.E. Wright and R.E. Beever. (Information Series No 16) Department of Lands and Survey: Wellington: 175-195.
Strecker, R. L., J. T. Marshall Jr., W. B. Jackson, K. R. Barbenhenn, and D. H. Johnson. 1962. Pacific island rat ecology. Bernice P. Bishop Museum Bulletin. 225: 1-274
Villa, B. 1982. Algunas aves y la rata noruega Rattus norvegicus "versus" el murcielago insulano Pizonyx vivesi en las Islas del Mar de Cortes, Mexico. Anales Instituto Biologia Universidad Nacional Autonoma Mexico Serie Zoologia. 50:29-36.
Whitaker, A. H. 1978. The effects of rodents on reptiles and amphibians. In: The ecology and control of rodents in New Zealand nature reserces. P. R. Dingwall, I. A. E. Atkinson and C. Hays, eds. New Zealand department of lands and surveys information series No. 4. p. 75-86.
