- American red squirrel, spruce squirrel, red squirrel, Sciurus hudsonicus, Tamiasciurus hudsonicus - of northern United States and Canada
--1 is a kind of tree squirrel
- red squirrel, cat squirrel, Sciurus vulgaris - common reddish-brown squirrel of Europe and parts of Asia
--2 is a kind of tree squirrel
--2 is a member of Sciurus, genus Sciurus