1. Red squirrel (Sciurus vulgaris)
With its signature russet brown fur, bushy tail and large ear tufts, the red squirrel is one of the UK’s rarest mammals. Red squirrels enjoy a diet of nuts and seeds, as well as tree flowers, buds, shoots, bark and lichen.
Once widespread, red squirrels are now few and far between. They were outcompeted by grey squirrels after greys were introduced from North America in the early 20th century. Weighing in at around 600g compared to the red’s 250g, grey squirrels adapted to changing habitats and foraged more efficiently.
Another threat facing the red squirrel is the fatal squirrelpox virus. Grey squirrels transfer it to reds, without actually becoming affected themselves.
Red squirrels are now only found in Scotland, Northern Ireland and the far north of England. They can inhabit deciduous or coniferous woodland. The UK population is around 140,000, compared to several million grey squirrels.