Every other Friday on Morning Edition NHPR’s Sam Evans-Brown tracks down answers to questions about the environment and outdoors for our listeners in a segment we call “Ask Sam.”
Brian from Hopedale, MA asks: “I was wondering why when you’re driving, why do birds always swoop in front of your car when they could easily just swoop above the road and above the cars? It’s something I’ve never understood.”
This will come off as kinda harsh on Brian, (sorry, Brian) but what we’ve got here is a fundamental misunderstanding of who’s swooping in on who.
“I feel like this is a common thing with people, and sometimes their interaction with nature is like ‘it’s all about me.’ Right. Like ‘why aren’t they moving out of my way?’” says Bridget Butler, the self-proclaimed Bird Diva (aka. a birder and consultant from Vermont). “Birds are out there to survive and so a lot of the reason why they’re swooping in front of us because they’re on a mission.”
It might seem like that bird is swooping in front of your car, but in reality that bird is just going about its business and you happen to be driving by at that moment.
So then the question is, why don’t birds fly higher than four or five feet off the ground? Windshield height?
The answer to that depends on the bird species.
If you’re a little bird, there are really good reasons to stick close to the ground. “The higher you fly just to make that simple trip, the more you’re susceptible to aerial predators and the more energy you’re expending as well by flying a little higher,” says Jason Ward, a birder from Atlanta and the host of the series Birds of North America.
Flycatchers sit out on low branches, wait till they see a bug and then dart out to go get it. Sparrows feed on the ground, hopping around looking for seeds and the like, and then the flit from one patch of feeding ground to another. When all these small birds move, they keep low to stay safe from birds of prey. Like little stealth jets.
But there are lots of reasons birds might be in the road and not moving. Vultures and crows might be trying to get a meal and don’t want to give that up the next tasty morsel. Raptors hunt by flying over or sitting next to large open spaces, and waiting patiently until a meal runs out into the open, and they can swoop in after them.
“Well we’ve seen multiple cases in which raptors are unfortunately dead on the side of the road with their prey either still clutched in their talons, or laying nearby,” says Ward.
Which leads us to a corollary side message: If you don’t want to see dead raptors on the side of the road, don’t throw food out your car window onto the side of the road.
That apple core that you huck out the passenger window?
“That attracts rodents which then attracts raptors,” says Butler.
How big of a problem is this? Cars kill at least tens of millions of birds each year, and maybe hundreds of millions. Youch.
Sam Evans-Brown, is host of NHPR’s Outside/In which you can subscribe to where-ever you get your podcasts. If you’d like to submit a question you can record it as a voice memo on your smartphone and send it to firstname.lastname@example.org, OR call the hotline, 1-844-GO-OTTER, OR submit it here.