You honestly think there are only 6 species living in any given city?
SD
Do you honestly think a city can approach the biodiversity of a wetlands, rain forest, or barrier island?
Most of the organisms in cities will fall into just a handful of species. By contrast, normal habitats have high biodiversity with significant numbers of many different species represented.
Let's see, in West Virginia in relatively undisturbed mixed forests and meadows you can find the following mammals plus one marsupial (a by no means exhaustive list, and completely ignoring birds, amphibians, reptiles, and fish):
white-tailed deer
coyote
black bear
eastern gray squirrel
fox squirrel
flying squirrel
eastern cottontail
snowshoe hare (some places in the mountains)
mink
fisher (rare)
several species of moles
several species of voles
several species of mice
raccoon
red fox
gray fox
bobcat
opossum
striped skunk
spotted skunk (less common)
beaver
muskrat
otter (recovering populations)
several species of weasel
In downtown Charleston, WV, you might find scrounging in the dumpster:
coyote
raccoon
opossum (occasional)
red fox (occasional)
eastern gray squirrel (yes, they're dumpster divers!)
You honestly think the biodiversity of downtown Charleston compares to the surrounding mountains?