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Meet the Owl that Fishes with Feces

Back in the early 2000s, ornithologist Doug Levey was teaching a course at the University of Florida when he had a weird idea about poop. 

He and some of his students were on a field trip observing burrowing owls—a tiny, long-legged species that makes its home in underground burrows. If you’ve seen photos of burrowing owls, you know they’re pretty cute. If you’ve seen them in the wild, you know they’re also pretty weird. Unlike most of their cousins, burrowing owls are active during the daytime, and spend most of their day standing around the entrances of their burrows doing what seems to be a whole lot of nothing. 

All of this standing around is done amid piles of dung, which the owls collect and arrange around their homes like bizarre lawn decorations. Cow dung. Horse dung. Dung from dogs, cats, antelope—you name it. If an animal shares territory with burrowing owls and poops, chances are the owls will take it home; they don’t seem to be picky about whose feces they’re collecting. But what do they do with all of it?

One of Levey’s students pointed out that there were lots of dung beetle parts scattered throughout the owls’ pellets, the masses of undigested food that some birds regurgitate. Levey quickly put two and two together. If you want to catch a dung beetle, he figured, you’d leave some dung out. Maybe the owls were using the poo piles as bait to lure in their prey. 

To test the idea, Levey and his beetle-spotting student Scot Duncan cleared all the burrows of two different owl populations of their dung, pellets, and beetle pieces. Then they went back and scattered cow dung around half of them and left the other half alone. A few days later, they collected the regurgitated pellets and prey remains from all the burrows and kept them for analysis. Then they repeated the experiment, this time switching the burrows that got fresh dung and those that didn’t get any. 

They found that the owls who had dung at their burrows ate much better than their dung-less neighbors; their pellets suggested that they consumed ten times as many beetles and six times as many different beetle species. 

While it might look like the owls are standing around doing nothing, they’re really fishing for beetles with some unconventional bait. 

It’s a fascinating bit of tool use, but no one can tell if the owls are consciously collecting the dung as bait, acting on instinct, or even bringing the dung home for another reason (like masking the odor of their eggs or chicks) and simply enjoying the beetle-luring effect as a bonus. 

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Animals
10 Notable Gestation Periods in the Animal Kingdom
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The gestation periods of the animal kingdom are varied and fascinating. Some clock in at just a few weeks, making any human green with envy, while others can last more than a year. Here are 10 notable gestation times for animals around the globe. The lesson? Be thankful that you’re not a pregnant elephant.

1. ELEPHANTS: 640-660 DAYS

Elephants are pregnant for a long time. Like really, really long. At an average of 95 weeks, the gestation period is more than double the length of a human pregnancy, so it shouldn't come as a shock that female elephants don't often have more than four offspring during their lifetimes. Who has the time?

2. HIPPOS: 8 MONTHS

A photo of a mother hippo and her baby in Uganda

Yes, it takes less time to make a hippopotamus than it takes to make a human.

3. GIRAFFE: 14-15 MONTHS

Baby giraffes can weigh more than 150 pounds and can be around 6 feet tall. Another fascinating tidbit: giraffes give birth standing up, so it's pretty normal for a baby to fall 6 feet to the ground.

4. KILLER WHALE: 17 MONTHS

There’s a reason for the long wait: after that 17 months, Baby Shamu emerges weighing anywhere from 265 to 353 pounds and measuring about 8.5 feet long. Yikes.

5. OPOSSUM: 12-13 DAYS

A baby opossum wrapped up in a blanket

Blink and you'll miss it: This is the shortest gestation period of any mammal in North America. But since the lifespan of an opossum is only two to four years, it makes sense.

6. GERBILS: 25 DAYS

Hey, they get off pretty easy.

7. GORILLAS: 8.5 MONTHS

It's not a huge surprise that their gestational periods are pretty similar to ours, right?

8. BLACK BEAR: 220 DAYS

A pair of black bear cubs

Also less than a human. Interestingly, cubs might only be 6 to 8 inches in length at birth and are completely hairless. 

9. PORCUPINE: 112 DAYS

This is the longest gestation period of any rodent. Thankfully for the mother, porcupine babies (a.k.a. porcupettes) are actually born with soft quills, and it's not until after birth that they harden up.

10. WALRUS: 15 MONTHS

Baby walruses? Kind of adorable. They certainly take their sweet time coming out, though.

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Goldfish Can Get Depressed, Too
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Don’t believe what Pixar is trying to sell you: Fish are not exactly brimming with personality. In aquariums, they tend to swim in circles, sucking up fragments of food and ducking around miniature treasure chests. To a layperson, fish don’t appear to possess concepts of happy, or sad, or anything in between—they just seem to exist.

This, researchers say, is not quite accurate. Speaking with The New York Times, Julian Pittman, a professor at the Department of Biological and Environmental Sciences at Troy University, says that fish not only suffer from depression, they can be easily diagnosed. Zebrafish dropped into a new tank who linger at the bottom are probably sad; those who enthusiastically explore the upper half are not.

In Pittman’s studies, fish depression can be induced by getting them “drunk” on ethanol, then cutting off the supply, resulting in withdrawal. These fish mope around the tank floor until they’re given antidepressants, at which point they begin happily swimming near the surface again.

It’s impossible to correlate fish depression with that of a human, but Pittman believes the symptoms in fish—losing interest in exploring and eating—makes them viable candidates for exploring neuroscience and perhaps drawing conclusions that will be beneficial in the land-dwelling population.

In the meantime, you can help ward off fish blues by keeping them busy—having obstacles to swim through and intriguing areas of a tank to explore. Just like humans, staying active and engaged can boost their mental health.

[h/t The New York Times]

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