Back in 2009, red squirrels were thin on the ground in Aberdeen - instead grey squirrels were a common sight in the city's trees and parks.

Today the red squirrel population is thriving thanks to the efforts of a group of volunteers and their "citizen science".

It is thought the invasive, non-native greys have been almost eradicated locally - and there is now evidence of red squirrel activity yards from the city's main thoroughfare.