Geography Reference
In-Depth Information
The diversity of mammals in a typical city is much lower than the diver-
sity of birds, and while they respond to urbanization in much the same fash ion—
some adapt or exploit, while others avoid—the relative proportions and notably
the place of origin of the animals in these categories is quite dif erent. The
majority of native mammals are urban avoiders, whereas the majority of adapt-
ers and exploiters are nonnative and often cosmopolitan species, such as the
Norway rat, house mouse, and eastern gray squirrel. There are notable excep-
tions where native mammals, such as l ying foxes, European badgers, and
hedgehogs colonize and thrive in urban settings. The response of cougars,
however, is more typical.
Cougars, also known as mountain lions or pumas, once lived across North
and South America. Today, they live mostly in the wilder portions of the con-
tinents, although increasingly they intersect the human world where subdivi-
sions spread into native forest or chaparral in the western United States and
Canada. Cougars are large and powerful cats that are capable of killing large
prey, some up to i ve times larger than themselves. As developments creep
into cougar habitat, the cats continue to use the natural habitat around settled
lands that hold their prey—mostly deer. Some occasionally prey on livestock
and come face to face with people in surprising places. Such conl icts, which
are most common in the exurbs, inevitably lead to cougar deaths. Cats that
repeatedly interact with people are often selectively killed. Others are hit by
cars, shot for no reason, or contract disease—notably feline leukemia—from
domestic cats and die. The result is that surviving cougars rarely spend more
than a i fth of their time in subirdia, and most stay far from it. For these reasons
most other native large carnivores, such as wolves and tigers, are also urban
avoiders.
That some mammals thrive while most others decline in urban landscapes
suggests that, as with birds, the makeup of mammal communities will transi-
tion in the face of new development. Indeed, as the chaparral outside of Los
Angeles is developed, native mammals that utilize woody vegetation, such as
