Habitat destruction is among the top causes of species endangerment and extinction around the world. As humans continue to expand city suburbs, build dams, and mow down old growth forests, wild animals have fewer and fewer natural landscapes in which to live.
Most species can’t handle the human encroachment, but we can to give credit to those species that have managed to adapt to city life. Life gave these species lemons and they made lemonade, so to speak.
Urban wildlife in the Pacific Northwest is a mixture of native and non-native animals. The natives include raccoons, deer, coyotes, opossums, bats, and most birds.
Mice, rats, squirrels, and some birds are non-native. By ‘non-native’ I mean that these critters weren’t in the northwest before European-Americans arrived—they tagged along with the pioneers and later immigrants.
The northwest seems to have pretty high concentrations of native wildlife in its cities. This might be because, for many cities in Washington and Oregon, large patches of natural habitat and agricultural land are often just a few stoplights down the road from downtown. Parks and green spaces, which are favorable to wildlife, are also common within the boundaries of our cities.
How have some species been able to adapt to life in our vast labyrinths of concrete, asphalt, and glass? What behaviors allow wild animals to thrive in urban environments?
A couple behaviors stand out to me…
They are not picky eaters
With people come heaping dumpsters, trashcans full of half-eaten food, showers of potato chip crumbs falling to the sidewalk, and bowls of cat food sitting on back porches. These represent a veritable cornucopia to those animals that are naturally equipped to scavenge for their dinners.
Raccoons have mastered the art of knocking over garbage cans to rummage through our waste. Raccoons— like crows, pigeons, gulls, and rats— are food generalists, rather than specialists. They are not picky and take advantage of resources that we consider worthless.
Perhaps without these animals picking up after us, our cities might need to hire a few more street sweepers and garbage truck drivers.
In addition to generating trash and accidental edibles, humans also intentionally feed some urban animals. There are whole stores dedicated to the purpose, in fact. For example, the Backyard Bird Shop carries supplies such as bird feeders and seed/suet, salt lick blocks for deer, and squirrel treats.
They make use of all the nooks and crannies we create
Some animals have learned that human structures, from storm drains to the cozy insulated walls of houses, can provide them with protection, warmth, and adequate space for nesting and raising their young.
Skyscrapers are crawling with pigeons, which would nest on cliffs in the wild. Bats roost beneath rain gutters. Opossums lurk in house attics and Swifts hang out in chimneys.
Cities have countless spaces that can be occupied, distributed in 3 dimensions, above and below the ground. Secretive, nocturnal animals have many places to hide during the daylight hours.
The animals that don’t survive in urban environments have habitat needs that can’t be met in cities. Many— probably most— species are very sensitive to disturbances of the natural balance of their ecosystems. There are thousands of things missing from cities that are absolutely necessary for the health of natural ecosystems. Cities just don’t cut it for most animals.
And cities are filled with things that pose direct threats to wild animals. Like, oh I don’t know… maybe cars?
You might be someone who loves the idea of sharing space with wild animals. Or maybe you cringe at the sight of raccoons and rats. No matter how you feel about them, urban animals are here to stay. As humans expand, so do populations of these creatures.
Over time, we may even see more species being forced to adapt to city life, as their natural habitats are squeezed into smaller and smaller gaps.
The topic of urban wildlife is complex and interesting. I have only scratched the surface here. Check out Kelly Brenner’s excellent blog The Metropolitan Field Guide if you are interested in learning more.
What are your thoughts on the coexistence of humans and urban animals? Have you had an interesting close-encounter? Tell us about it!
- Portland’s Ecosystem Supports Array of Urban Wildlife—Some in Your Backyard!
- Portland Audubon Society’s Backyard Habitat Certification Program
- A short, ’80s-retro documentary on wildlife in Vancouver, BC – Wild in the City