Fauna of Polar Regions 
animal to be protectively coloured. If, it is 
urged, those creatures that live in lands which 
are covered in snow for half of the year have 
become white in winter by the action of natural 
selection in order to escape their foes, it is 
obviously of paramount importance to all 
creatures that they should be cryptically 
coloured. Popular books on natural history 
convey the impression that during winter the 
snow-clad, ice-bound Arctic regions are peopled 
by a fauna whose fur or hair rivals in whiteness 
the snowy mantle of the earth. The impression 
thus conveyed is misleading. It is true that an 
unusually large percentage of the animals that 
inhabit the polar regions are white in winter, but 
the majority of the creatures which dwell there 
do. not assume the white garb of winter. 
As the fauna of the polar regions is a small 
one, we are able to give lists of all the birds and 
mammals which dwell in the Arctic and the 
Antarctic regions. We have arranged these in 
in three columns. In the first are placed those 
creatures which are white throughout the year, in 
the third those that retain their colour through 
the winter, while the middle column contains 
those forms which change their colouring with 
the season. 
