Field guide to the most commonly encountered mammals and birds

Here, we provide some basic information regarding commonly observed species (plus some others about which we have had queries).  

Feel free to contact us by email if you have any questions regarding species you have encountered on the site.

For more information about mammals, we recommend the Mammal Society's species hub, here. For birds, excellent resources are available from the RSPB (here) and the BTO (here).


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Red squirrel


Scientific name: Sciurus vulgaris 

Family: Sciuridae

Appearance: These squirrels are reddish-brown, with the red fading somewhat in winter, and white underparts. They have tufted ears and bushy tails.

Size: Body length: 32-44 cm Tail length: 15-20 cm Weight: 250-350 g

Natural history: Red squirrels are forest-dwellers, spending more time in the treetops than greys. Their nests, called dreys, are high-up, in holes in trees or woven from twigs. Red squirrels do not hibernate, but may shelter in a drey for many days in bad weather. They eat nuts, seeds, berries, bark and fungi. Through the autumn, they stockpile nuts to feed on through the winter when other food sources become scarce.

Red squirrels have two litters per year, normally of three or four young called kittens. During bad years for the pine cone crop, squirrels can delay gestation until the following year.

Red squirrels can be right-handed or left-handed, seen in the way they eat pinecones.

A virus carried by invasive grey squirrels has caused serious declines in Britain’s red squirrel population. Red squirrels survive in a continually-shrinking area of northern England, parts of Scotland, and scattered populations protected by the eradication of greys. Many conservation groups are developing programmes to help them reoccupy their natural range, which they readily do when greys are controlled.

 (C) Bob Hall (shared under a CC BY-NC-ND 2.0 license)