Santander dwarf squirrel

The Santander dwarf squirrel (Microsciurus santanderensis) is a small tree squirrel endemic to Colombia. It measures around 15 centimetres from nose to rump, with a tail about as long again, and females are on average slightly larger than males. It was originally described as a subspecies of the Andean squirrel and resembles that species but is somewhat smaller, with reddish-orange fur over most of the body, a black line down the centre of the back and paler, pinkish-buff underparts. Its range is unclear because it is often confused with the Andean squirrel; it is known definitively only from land between the middle Magdalena River and the western slopes of the Cordillera Oriental, in heavily forested country at 100 to 3,800 metres. Very little is known of its biology, and the IUCN lists it as data deficient.