Barn Owl Table Manners are Just ... Different
Barn owls swoop down on rodents and swallow them whole – gophers, voles and mice, gone in a few gulps. But how do they keep down all that food? Well, they don’t. In a few stomach-turning steps, they transform the varmints into compact balls of fur and bones known as pellets.
Scarfing down their food whole keeps barn owls moving.
After all, these hungry birds gotta eat and there are lots of little rodents to hunt.
Barn owls need a hole to nest in, and when a tree isn’t available, they’ll use a building. Or an owl box, like this one in California’s Napa Valley. Scientists keep tabs on the owls inside.
Winegrowers invite barn owls to raise their young in the boxes because owls are pest control machines.
I mean, a barn owl family can kill about 3,500 varmints a year. They don’t take ’em all out, but they can make a dent.
They particularly like gophers, like this stunner right here. Their constant tunneling damages roots and irrigation lines.
And then there’s voles, which gnaw on the grapevines.
This 2-week-old owl already has the hang of it. But how the heck does it keep down all that food?
Well, it doesn’t.
Meet the owl pellet.
Check out this furball.
And here’s a jaw. Gnarly!
The secret to turning this into this is its stomach. It has two chambers.
The first one oozes digestive juices, like our stomach. The second one – the gizzard – squeezes the remains with powerful muscles.
The fats and proteins get absorbed. The fur and bones become tightly compacted.
After about eight hours in the gizzard, the result is one of these beauties.
For researchers like Laura Echávez, from Cal Poly Humboldt, pellets are forensic evidence.
She carefully dissects them to find out how many pesky gophers and voles the owls took care of.
Laura (off camera): The tail still has skin on it.
This unlucky rodent had a small skull. It could be a vole.
But then she examines the teeth.
Laura (off camera): The teeth are actually looking more like a gopher’s.
They’re kind of circular, surrounded by a white ring of enamel.
And the first and second teeth are joined by a bridge. Classic gopher trademarks.
Laura (off camera): If it’s a gopher, it’s a very young one, because this is on the small side.
Sometimes more than one carcass is crammed into a single pellet.
This one had two gophers.
Winegrowers love barn owls for their prolific appetites. But researchers still don’t know whether vineyards are an ideal place to raise an owl family.
Christian Cortez, a researcher at Cal Poly Humboldt, studies young owls to see how well they’re growing.
After covering their head to calm them down, he takes a drop of blood, and plucks a feather. They will tell him if the owlet is getting enough to eat.
Researchers want to know, do owls have enough open space to hunt in?
And do the toxic chemicals Napa winegrowers sometimes use to kill rodents end up hurting the owls too?
As scientists explore these questions, we’ll find out if barn owls are really getting a good deal.
Hey Deep Peeps. I’m science journalist Maddie Sofia, sitting in for Laura until she returns this fall.
Do you know what makes owls such quiet, deadly hunters? Watch our episode about how owls fly to find out.
Also, check out a wild new show on PBS Terra called “Far Out.” It explores how changes in science, technology and culture are reshaping life on Earth. Tell them Deep Look sent you. Thanks!