46 THE TAIGA, OR CONIFEROUS 
warmer parts of its range. The polecats, of which one 
(M. eversmannia) occurs in Siberia, the common weasel 
(M. vulgaris), found both in Northern Asia and in 
Northern America, and the stoat or ermine (M. erminea) 
as already indicated, are not definitely forest animals, 
though they are found there as well as elsewhere. The 
mink (M. vison) of North America, and the Siberian 
form (M. siberica) haunt streams and lakes, and are 
forest animals to the extent that localities suitable to 
their habits often occur within forest areas. 
On the other hand, the wolverene (Gulo luscus), 
a fierce and voracious carnivore, is chiefly found within 
the forest, where it preys upon all manner of small 
mammals and birds, and even attacks weakly or 
disabled deer. 
The common badger (Meles taxus) is found in the 
Siberian forests, and, though a burrowing form, occurs 
chiefly in woods. On the other hand, the American 
form (Taxidea americana) is chiefly a prairie mammal, 
and feeds largely upon the prairie marmots (see p. 64). 
Passing now to the birds, we find that the forest is 
rich in specially adapted forms, and that in addition 
there are large numbers of migrants who spend part of 
their time there. The forest gives relative security 
during the dangerous period when brooding is taking 
place and the young are being reared. The absence or 
paucity of snakes in the northern forest also, and the 
complete absence of monkeys as well as of the many 
carnivorous or egg-eating animals which haunt tropical 
forests, increase the value of the northern forest from 
the birds’ standpoint, and help to account for the 
number of species found there in summer time. Among 
forms which are especially abundant in northern 
forests, or especially adapted to life there, we may 
