Nearly 70 species of wild mammals live in Missouri, and in
numbers of species, mammals (in the phylum Chordata) are the
second smallest group of vertebrate animals in our state. One
mammal, however, takes up more space in Missouri than any other:
humans. Most of us recognize mammals easily: They have fur, are
warm-blooded, nurse their young and breathe air. Armadillos and
opossums, bears and skunks, bats, rats, deer and cats are all
mammals. Many of the characteristics of mammals help to maintain
a fairly constant body temperature: Mammals eat heavily and
fatten up to survive winter’s cold. Fat and fur provide
insulation, and shivering raises the hairs, which “fluffs the
comforter.” Some mammals hibernate. Many build burrows or
special nests to avoid temperature extremes. Missouri has only
one mammal in the marsupial group, the opossum. It gives birth
to tiny young that seem “premature” compared to other mammals.
Newborn opossums complete their development as they nurse inside
their mother’s pouch. All the ot