Gambian Pouched Rat (Cricetomys gambianus)
The Gambian pouched rat is native to Africa and is the world’s largest rat, reaching up to 9 pounds. The average size is 3 pounds, measuring 20-35 inches from the head to the tip of the tail. The body is gray to brown in color, with a lighter belly. Beyond its large size, this rat can be distinguished by its long (14-18 inches), almost hairless tail, with the last third a lighter, off-white color. The Gambian pouched rat gets its name from the way it collects food by stuffing its cheek pouches.
In their native range of Africa, Gambian pouched rats live in natural crevices and holes, termite mounds or hollow trees in forests, thickets and around human dwellings. In Florida, they are often seen around houses, particularly where pets are fed outside. They are primarily nocturnal and can climb well, but spend most of their time on the ground.
Africa – Senegal to central Sudan, South Africa
The only confirmed sightings in Florida have been in the Florida Keys with breeding confirmed on Grassy Key, a small key (island) that is part of the city of Marathon in Monroe County.
History of introduction and management
The FWC has been aware of a breeding population of Gambian pouched rats since 2004. Gambian pouched rats were imported as pets into Florida until importation was banned in 2003. The rats were bred in captivity on Grassy Key, where eight rats escaped and established a breeding population, which was reported to the U.S. Fish and Wildlife Service in 2004. The FWC, working with USDA Wildlife Services and the city of Marathon, has been trapping the rats and monitoring for them via remote cameras since 2005, with the goal of ensuring that what is believed to be a small population does not grow and expand to other parts of the state.
Gambian pouched rats feed on insects, snails, nuts, seeds and fruit. They are opportunistic and will eat pet food if it is available. They get their name by the way they collect food in their cheek pouches.
While Gambian pouched rats have been confined to Grassy Key, the concern is that they may make it to the mainland and pose a threat to Florida’s agricultural industry in south Miami-Dade County. These rats are larger than native Florida rat species, including the Key Largo wood rat, cotton rat and silver rice rat, as well as the nonnative common black rat.
Gambian pouched rats reproduce easily and can have up to five litters in the span of nine months, with an average of four young per litter.
The rats are known carriers of monkeypox, a viral disease that can spread to humans. To date, no rats trapped from Grassy Key have tested positive for this disease.