Cities are just for people, right? Wrong. Nature is all around us, even in places with sidewalks and buildings. Species that benefit from and live close to humans are called synanthropes. They include the raccoons that cleverly raid the garbage can, the cellar spiders spinning webs amongst ceiling fans, the coyotes trotting along railroad tracks and alleyways.
To be clear, these are not domesticated animals like your pets. Nor are they raised as livestock like cows or chickens. They are wild animals that have made a home with us in landscapes we have changed: cities and suburbs. A dog is not a synanthrope, but a pigeon eating crumbs off the sidewalk is.
They can be native, which means they are from the area. An opossum is a synanthrope native to Will County. Other synanthropes, like the Norwegian rat, are not native.
Words to know
Domesticated: Tamed and kept as a pet.
Livestock: Farm animals raised as a product for market.
Synanthrope: A wild plant or animal that lives near or benefits from artificial habitats people created for themselves.
The true mark of a synanthrope is the ability to thrive in cities. There are a lot more raccoons and foxes in urban areas — almost twice the amount! — than in the countryside.
Some synanthropes have been living together with people for centuries! Norwegian rats have moved all around the world with people, making our habitats theirs. Sometimes these animals’ lives are so intertwined with humans that they might not be able to survive without us. A cellar spider’s home is your home. “Freeing” it outside might just kill it.
Not all synanthropes are animals. Plants can be synanthropes, too! Dandelions and lawns of our common grass, called Kentucky bluegrass, flourish thanks to our yards. Let’s take a look at some of the synanthropes that live among us.
Raccoons are incredibly clever. Do you ever feel like they are getting better and better at breaking into your garbage cans? Well, you are right. Scientists have found that urban raccoons are greater problem solvers and better able to manipulate things like trash bins or bird feeders than their rural cousins. City dwellers are also bolder. These omnivores are the ultimate scavengers, able to eat almost anything we leave out. This flexibility makes them a great success!
Found a place with lots of humans? Chances are you will find crows or their corvid cousin, the raven. They are intelligent and able to adapt to our developed and littered spaces. They can eat nearly anything — insects, seeds, pizza crusts, even cardboard. Urban crows eat up to 50% garbage. They even use us to help with dinnertime. One group of crows was seen dropping peanuts in front of car wheels at stoplights. After the car crushed the shell, the birds retrieved the treat inside!
Common house spiders
The common house spider is found all over the world. It originally came from Brazil, but it is able to survive in places like Will County because it has taken up residence in our warm, cozy houses. By the time scientists properly identified them, they had made their way to Germany.
Only some common house spiders can live outside in warmer temperatures. Even then they like bridges and other structures to make them feel safe. Uneasy about sharing your home with spiders? They pay us back by eating things you like even less, like flies, mosquitoes and cockroaches.
When you get down to it, there are a lot of cool synanthropic species out there. Some other examples are the house mouse, house fly, American robin, Canada goose, gray squirrel, opossum, skunk and purslane, to name just a few.
Head outside and keep your eyes peeled for these urban dwellers. Just don’t forget that these are wild animals and should never be approached. How many can you see? What are they doing? Let the synanthropic search begin!
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