Giant pouched rat

Giant pouched rat
Temporal range: Recent
Cricetomys emini
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Nesomyidae
Subfamily: Cricetomyinae
Genus: Cricetomys
Waterhouse, 1840
Species

Cricetomys ansorgei
Cricetomys emini
Cricetomys gambianus
Cricetomys kivuensis

The giant pouched rats (genus Cricetomys) of sub-Saharan Africa are large muroid rodents. Their head and body lengths range from 25–45 cm (9–18 in) with scaly tails ranging from 36–46 cm (14–18 in). They weigh between 1.0 and 1.5 kg.

Contents

Natural history

Giant pouched rats are only distantly related to the true rats, but are instead part of an ancient radiation of African and Malagasy muroids in the family Nesomyidae. They are named due to their large cheek pouches.

Females have been suggested to be capable of producing up to 10 litters yearly. Gestation is 27–36 days. One to five young are born at time. Females have eight nipples.

The animals are nocturnal. They are omnivorous and feed on vegetation and invertebrates. They have a particular taste for palm nuts. They are coprophagous.

They can become tame and are kept as pets. They are also an important food source in many African countries.

Ability to detect land mines and tuberculosis by scent

These rats are also becoming useful in some areas for detecting land mines, as their acute sense of smell is very effective in detecting explosives, and they are light enough to not detonate any of the mines.[1][2] The rats are being trained by APOPO, a nonprofit social venture based in Tanzania.

The procedure for training rats to detect land mines was conceived of and developed by Bart Weetjens of the Netherlands. Training starts at four weeks of age when the rats are handled to accustom them to humans and exposed to a variety of sights and sounds. They learn to associate a clicker with a food reward of banana or banana-peanut paste. They are then trained to indicate a hole with TNT in it by nosing it for five seconds. Then they learn to find the correct hole in a line of holes. Finally, the rat is trained to wear a harness and practises outdoors on a lead, finding inactivated mines under soil. At the end of their training, they are tested: they must find all the mines in an area of 400 square metres that has been seeded with inactivated mines. It is a blind test: their handlers do not know where the mines are. If they succeed, they are certified as bomb-sniffing rats. It is cheaper to train a rat than a dog, so cheaper to find land mines using rats.[3]

APOPO is also training the rats to detect tuberculosis by sniffing sputum samples; the rats can test many more samples than a scientist using more traditional methods—hundreds in a day vs. 30 to 40.[4] Land mine and tuberculosis sniffing rats are called HeroRATs.

Species

Genus Cricetomys - Giant pouched rats

In pop culture

Ben, in the 2003 remake of Willard, was a giant pouched rat.

Notes

  1. ^ Wood, Ian (18 Dec. 2007). "Rats being used to sniff out land mines". Telegraph.co.uk. http://www.telegraph.co.uk/earth/earthnews/3319113/Rats-being-used-to-sniff-out-land-mines.html. Retrieved 2008-11-23. 
  2. ^ Giant rats sniff out Mozambique's mines IOL
  3. ^ Weetjens, Bart. How I taught rats to sniff out land mines, TED Talks, Rotterdam, 2010 (accessed 2011-09-16)
  4. ^ "Fighting Tuberculosis". herorat.org. Archived from the original on 2008-08-04. http://web.archive.org/web/20080804041055/http://www.herorat.org/en/fightingtuberculosis. Retrieved 2008-11-23. 

See also

References

External links