DRY FOREST MARGIN 269 
j I. SUBTERRANEAN-GROUND STRATUM 
Certain earthworms, cicada nymphs, and root-eating grubs belong 
here. This is the regular breeding-place of the skunk (Mephitis meso- 
melas avia Bang). According to Seton (143) they go in droves of six or 
eight, and as many as fifteen sometimes occur in a winter den. Accord- 
ing to Seton its food consists of various insects, grasshoppers, crickets, 
meadow mice, snakes, and crayfishes. The short-tailed shrew in primeval 
conditions breeds chiefly in such tangles of bushes. It digs in moss 
and fallen leaves and loamy soil, and follows mouse galleries. According 
to Wood (21) it eats many mice. Seton (143) states it feeds on isopods, 
earthworms, etc. Its enemies are hawks, lynxes, and weasels. 
Franklin’s ground squirrel (Citellus franklini Sab.) burrows into the 
ground deeper than the ground squirrel of the prairies, but is otherwise 
similar in habits. It is gregarious and stores grain for winter. The 
chipmunk (Tamias striatus griseus Mear.) is a typical forest margin 
animal. It nests in the ground, as a rule in burrows about 6 to to ft. 
long and running diagonally down to a depth of 2 to 3 ft. (21). It stores 
nuts for winter. The jumping mouse (Zapus hudsonius Zim.) is one of 
the most characteristic residents; it moves by great leaps and steers its 
flight with its tail. The woodchuck should probably be counted here, 
though it belongs deeper in the forest than any of the others. The weasel 
is common in this situation, though it is perhaps more abundant along 
streams (Wood). 
The ground stratum supports many of the small animals of the 
adjoining forest, such as centipedes, camel crickets, etc. The cottontail 
is one of the chief residents, as it usually breeds in such situations. The 
common shrew (Sorex personatus St. Hil.) (21) breeds on the ground, in 
stumps, etc. All of the mammals recorded in the preceding stratum 
feed here when suitable food is present. A considerable number of 
mammals commonly regarded as belonging to the forest are said to prefer 
thickets. The Virginia deer is one of these. It is probable that the elk 
was somewhat similar in habits. 
The bobwhite and mourning dove (occasionally) breed in these situ- 
ations, the former often falling a victim to the weasel (Wood).. The 
high forest margin was probably a favorite location for the huts of the 
aborigines. Some of the early travelers record huts around the edges of 
the prairies. Such locations would supply shelter and firewood, etc., as 
well as sunshine. 
2. FIELD AND SHRUB STRATA 
Here the ground-cherry, milkweed, and thistle have a characteristic 
fauna. On the milkweed are the larvae of the monarch butterfly, the 
