I’m lucky to live in a part of Los Angeles where lots of urban wildlife sings, squawks, and chatters nearby. It makes me feel all warm and fuzzy inside to see that so many species appear to have adapted really well to urban living — acorn woodpeckers, skunks, mocking birds. And yet, they may not all be doing as well as I think they are. In fact, some of them would probably be way better off getting out of town.
In a creepy phenomenon called an “ecological trap,” animals can be lured into a habitat that’s actually bad for them. Here’s how it works. An animal — a Cooper’s Hawk, for example — goes in search of a nice neighborhood in which to settle down and raise a family. Let’s say he lands a great deal, a prime spot for a nest in a choice location: a great view, loads of prey, and plenty of good perches. His wife is impressed. They move in and incubate some eggs.
But the family is doomed. The hawks, it turns out, were wrong about this neighborhood. They find themselves in an alternate and frightening universe where their senses, their judgment, and everything they know about the world betrays them. What they’d thought was safe and trustworthy is actually deadly. The plentiful and easy prey are almost entirely doves. And they carry a deadly disease that kills the hawks’ young.
And the same thing happens to a bunch of other hawk families who thought they were moving to a posh street in Beverly Hills.
To make the best choices in life, animals rely on cues that have worked for thousands, sometimes millions of years. To the mind of a Laysan albatross, for instance, anything floating on the surface of the ocean is food — and that’s logical, because everything floating on the surface of the ocean used to be food: squid, dead fish, or fish eggs. Now, of course, it’s more often plastic bags and discarded toothbrushes, and the Laysan albatross is in trouble. An ecological trap happens when false indicators tell an animal that a certain habitat is high quality when, in fact, it isn’t.
Not surprisingly, ecological traps seem to happen most often in urban areas, where the rules have changed, and very recently. Cues that used to indicate a good neighborhood now misinform prospective tenants.
Ecological traps occur without human intervention, too. The phenomenon hasn’t been studied that much, I’m told, but presumably it happens whenever the circumstances change and the code for survival is rewritten. It’s just like your credit card company — rules subject to change without notice. Still, it seems certain that the false cues created by human civilization are creating new ecological traps at an unprecedented rate.
Sometimes, ecological traps lure in so many animals that the populations in healthy habitats start to diminish. The trap becomes like a black hole, feeding its vortex with unsuspecting newcomers. Biologists call this phenomenon an ‘ecological sink.’ Even creepier. And while the impact of humanity rewrites the rules faster and faster, the only defense of a species is the slow and uncertain process of adaptation.