The list of mammal species that live in Costa Rica reached 250 this month, after scientists spotted a rufous tree rat (Diplomas labilis) in the country’s south. The rodent had previously only been known to range from central Panama south to Colombia.
The arboreal rat is known for its spiked fur, giving it its name in Spanish, ratón espinoso. Researchers spotted the rat in a hole in a tree in La Palma in the Osa Peninsula. One of the researchers climbed a nearby tree to photograph the rat. The group’s findings were published this month in the biodiversity data journal Check List.
José Ramírez, the paper’s lead investigator, wrote that the rat has likely always been in Costa Rica, and was simply overlooked.
“Nocturnal and highly arboreal mammals, such as the rufous tree rat, are often missed during biodiversity surveys due to their inaccessible habitat and a general absence of arboreal trapping.”