Study maps out evolutionary history of squirrel

A group of researchers at Stellenbosch University are working on a project to map out the evolutionary history of Smith’s bush squirrel a species of tree squirrel indigenous to the savanna of sub-Saharan Africa.

According to the group, the species is unique among tree squirrels as it lives in family groups, rather than being solitary.

The university’s Department of Conservation Ecology and Entomology said: “In South Africa, Smith’s bush squirrels frequent savanna woodland in Limpopo, Mpumalanga and the North West, where they often inhabit the hollowed branches of old mopane and acacia trees. In towns and on farms and wildlife estates they are sometimes deemed to be pests, because of their tendency to damage thatched roofs and electric cables.”

Over the last few years, about nine subspecies of Smith’s bush squirrel have been recognised across sub-Saharan Africa, generally according to the colour of their coats. Prof Sonja Matthee, project leader from the department, said that classification of species based on colour and size alone no longer hold in an era where genetic testing is possible. “It is possible that such colour differences only reflect how an animal has evolved to adapt to local environmental conditions, rather than it being a real genetic difference between subspecies,” she said.

The research team is conducting the first study on the squirrel’s evolutionary history. This will hopefully shed light on the genetic variation between certain populations, and how this relates to where the animals have historically been found.

The department said that it was collecting samples from key distribution areas. This would help determine whether Smith’s bush squirrels from different regions differ genetically.

The work was being done with Prof Conrad Matthee of the university’s Department of Botany and Zoology.

Matthee, an expert on the parasites that Southern African rodents carry, said: “Only one study has yet been done on the squirrel’s parasites, in 1977, and it only listed some of the parasites found on the animal.

“Not all squirrels carry parasites. This has so far made it difficult for us to collect enough samples for the parasite specific part of the study,” added Matthee. The team wants to obtain more animals from Mbombela/Komatipoort, Groot Marico/ Zeerust and Thohoyandou/Musina. They also hope to extend the study to include samples from neighbouring Namibia, Botswana, Mozambique and Zimbabwe. –

SONJA MATTHEE Smith’s bush squirrel (Paraxerus cepapi) is a species of tree squirrel indigenous to the savannas of sub-Saharan Africa.