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You aren't the only animal with a pantry!

Hosted by: Michael Aranda
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Sources:
Penguin
http://www.nature.com/nature/journal/v408/n6815/full/408928a0.html
http://jeb.biologists.org/content/jexbio/207/15/2715.full.pdf
http://www.jbc.org/content/278/51/51053.full?sid=8a314b8b-25cb-4d03-b475-a492ebc1d8e0
http://www.int-res.com/abstracts/meps/v237/p291-300
http://www.sciencedirect.com/science/article/pii/0300962989901217

Shrike
http://www.behaecol.amu.edu.pl/papers/downloads2005/files/ARDEA%2093%20101-107.pdf
http://www.sciencedirect.com/science/article/pii/S0376635715300097
http://www.sciencedirect.com/science/article/pii/S0376635705000392
http://www.academia.edu/17346170/Predator_exaptations_and_defensive_adaptations_in_evolutionary_balance_No_defence_is_perfect


Red squirrels
http://www.bioone.org/doi/full/10.1898/1051-1733-96.3.240
http://www.bioone.org/doi/full/10.1656/1092-6194%282007%2914%5B145%3AUOARNA%5D2.0.CO%3B2
http://www.nrcresearchpress.com/doi/pdf/10.1139/z03-224
http://www.bioone.org/doi/full/10.2193/0091-7648%282006%2934%5B467%3AUOWBBA%5D2.0.CO%3B2
https://www.jstor.org/stable/1373370

Mole
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0003472
https://books.google.com/books?id=AhlvmkSkxeYC&pg=PA223&lpg=PA223
http://www.sciencedirect.com/science/article/pii/S1631068313000717

Shrew
http://www.mdpi.com/2072-6651/7/7/2639/htm

Pika
http://www.bioone.org/doi/full/10.1644/08-MAMM-A-261.1
http://www.bioone.org/doi/full/10.1657/1938-4246-45.3.396
http://www.bioone.org/doi/full/10.1657/1523-0430%282006%29038%5B0054%3ASOFPSI%5D2.0.CO%3B2
http://onlinelibrary.wiley.com/doi/10.1890/0012-9658(1997)078%5B0774:TMOPTB%5D2.0.CO;2/full

Tayra
http://link.springer.com/article/10.1007/s00114-011-0821-0

Ragworm
http://onlinelibrary.wiley.com/doi/10.1002/ecy.1613/full

Images:
Lubber grasshopper
https://commons.wikimedia.org/wiki/File:Grasshopper_2.JPG

Ragworm
https://commons.wikimedia.org/wiki/File:Ecomare_-_zager_worm_(4856-worm-zager-mok-ogb).jpg

 Intro (0:00)


Michael: It’s a pretty common problem. You have some food, you chow down... and you get full, so you want to save some for later, when you’re hungry again. Or maybe you know that you won’t be able to get more food for a while, so you stockpile. You protect your stash from others, and try to keep it from spoiling.

Now, I don’t want to sound like I’m bragging here, but humans are pretty good at this. We invented canning and drying; refrigeration and freezing; pasteurization and all kinds of preservatives.

You name it, we’ve probably done it to make food last longer. But other animals have some tricks up their sleeves, too. So here are 8 wacky techniques our fellow food-lovers have come up with to stay alive.

 Penguins (0:40)


King penguins store food in a super convenient place: their stomachs. And they can keep it there, undigested, for weeks at a time. The birds breed on subantarctic islands, and once the female lays the egg, both parents will take turns watching the nest while the other goes fishing.

Usually, the male penguin takes the last shift before the egg hatches. But sometimes the female is delayed getting back, because the birds’ foods of choice are lanternfish and squid that live 400-500 kilometers south. So, to make sure the infant bird has something to eat in case mom is late, a penguin father will come back from his last foraging trip with a full stomach.

And for up to three weeks after he gets back, he’ll live off his fat reserves and preserve his stomach contents -- a tasty mash of fish and squid parts ready to be coughed up into a hungry chick’s mouth. It’s enough food to nourish the chick for 9-10 days.

What’s especially strange about this is that the food doesn’t rot, even though it’s just sitting around. At first, scientists thought that the penguins might preserve the food by lowering the temperature inside their stomachs to basically turn themselves into mini fridges. But their stomachs are actually a toasty 38 degrees Celsius.

It turns out that they keep the food fresh by making their stomachs less acidic, which keeps digestive enzymes from processing the food, and by stopping their stomach muscles from churning it too much. They also release antimicrobial proteins called spheniscins to stave off bacteria and fungi.

 Shrikes (1:58)


Shrikes are smallish birds that you might underestimate... until you see them spear their prey on thorns, pointy branches, or even barbed wire -- whatever sharp object they can find. Then they’ll spend the next couple of days ripping pieces off these ad-hoc skewers and eating them.

It’s thought that shrikes evolved this special butchering method because unlike other birds of prey, they don’t have talons to help pull apart meat. Shrikes also don’t have crops, the internal pouches many birds use to store food, so they can’t eat their entire kill all at once. Instead, they have to be dainty about it — if you can call regularly ripping flesh off of a spit dainty. They’ll also impale their food to detoxify it, which gives them more options for food sources.

Loggerhead shrikes in Florida, for instance, are known to spear poisonous species, including the notorious lubber grasshopper, which is so toxic that it doesn’t have many predators. The grasshoppers are dangerous to the birds when they’re fresh, but after one to two days decomposing on a stick, the chemicals degrade and lose their potency.

If you’re thinking that it must be risky to leave your food out in the open on a stick, you’re right. These stashes are often raided by other animals. But for shrikes, that risk is actually important, because if a male has lots of food stored up, that’s a signal to females that he’s good provider.

During mating season, males will even add inedible items like rags or pieces of eggshell to make their spiky pantries look bigger and draw attention to them. And in many cases, they won’t eat all the food — it’s just for show.

Once it’s time to incubate eggs or feed babies, though, the larders become much more important for sustenance. The birds will eat more of the food and keep the stores closer to their nests and better hidden. Their chicks are born with an instinct to impale. Young birds will start by playing with inedible objects with their bills in what’s officially called “dabbing.” Yep, baby birds have better dance moves than you.

 Red Squirrles (3:33)


OK, so we all know about squirrels and their precious acorns. But red squirrels primarily eat pine cones -- and also collect and store a more unusual treat: mushrooms. They preserve the mushrooms by hanging them in trees to dry, then move them to safe hideaways to snack on later.

The ‘mushroom jerky’ comes in at least 89 varieties, and includes some pretty highbrow stuff — like false truffles, which are mushrooms that look a lot like the truffles you’ll find in fancy food. And for some squirrels, mushrooms aren’t just a side dish.

For red squirrels in New Brunswick, Canada, anywhere between 35-95% of their diet is fungi, depending on mushroom availability and whether they can find other kinds of food. They’ll typically capture lots of mushrooms in the summer, then preserve and save them to eat during the winter.

Some squirrels seem to prefer bare branches -- and therefore dead trees -- as dehydration spots. They’ll then store the mushrooms in tree hollows, or in the tangles in trees known as witches’ brooms. But squirrels will also use whatever dehydration and storage spots they can get.

In 1911, for example, a fur warden found an abandoned cabin in Alaska full of preserved fungi. A red squirrel had broken in, dried mushrooms on all the shelves, and stowed the pieces in empty cans.

 Moles (4:41)


One way to avoid the headache of preservation is to just keep your prey alive, but trapped. And that’s exactly what moles do. They’ll hunt earthworms and insect larvae in dirt, then bite off their heads to immobilize them.

They’ll stash the food in the walls of their tunnels, or in special chambers near nests, to eat later. And it’s a good strategy: some moles pack those chambers with more than 1,200 worms.

Moles are such effective earthworm hunters that scientists think worms have actually evolved an instinctive response to avoid them. When they sense mole-like vibrations in the ground, worms will escape to the surface. Unlike squirrels and lots of other food-caching animals, moles don’t store up for a specific season.

They’re active year-round, searching for and nabbing worms for their collections. But frozen ground does make it easier to grab prey, so they’ll collect more worms in the winter. Winter also helps with another problem: the worms eventually regrow their heads, which means they can move again. But when the ground is frozen, they can’t squirm away.

 Shrews (5:29)


Shrews, like moles, are master tunnelers with a taste for earthworms, though they also like snails, insects, and the occasional small mammal. But some shrews add an extra element to their hunting strategy: venom. The American short-tailed shrew has what’s called blarina toxin in its saliva, which subdues victims after a bite.

Since the meal is alive, it won’t spoil. And since it’s paralyzed, it also can’t run away. Shrews really need to keep extra meals around, especially if they’re going to survive the winter.

See, shrews have ridiculously high metabolisms -- they need to eat their weight in food every day And during the colder months, food can be harder to come by. The venom might also let certain shrews take on larger animals like frogs. And when you have a shrew’s metabolism, anything that gives you more food options is an advantage.

 American Pika (6:10)


But not all burrowing mammals with a penchant for hoarding are meat-eaters. The pika doesn't have a lightning bolt-shaped tail, and you can't catch it with a PokeBall. Instead, it's a small creature that looks like a cross between a mouse and rabbit, is perfectly happy eating plants.

Problem is, American pikas live in the mountains of western North America, where it can be pretty hard to find plants it can eat in the winter. So pikas collect hay in the summer, dry it, and save stashes between rocks to eat when it's cold. But there’s more to this than just saving food for later.

Wildlife biologists have noticed that the plants pikas eat in the summer aren’t the same plants they save for winter. The hay they store contains much higher levels of tannins, the bitter organic molecules you’ll also find in wine. And for many animals, probably including pikas, tannins are toxic.

But with time and dehydration, tannins degrade. And in the meantime, they help preserve the hay. So, the pika can eat plenty of the good, non-toxic stuff while it’s foraging, and collect and save the bad hay until it’s aged into a tastier, safer food.

 Tyra (7:07)


The tayra, a weasel relative found in Central and South America, also uses time to its advantage. Tayras are known to pick plantains when they’re green, hide them away, and come back a few days later to eat them when they’re ripe. The animals will do something similar with sapotes, a type of native fruit, which will only ripen off the plant once it’s already mature.

Now, tayras will eat pretty much anything, and these fruits are just one part of their diet. But the idea that an animal seems to have the foresight to grab a food before it’s ripe -- and to pick it at just the right time -- has some scientists wondering if tayras and other animals with similar habits are capable of what’s called prospective thinking.

Is the tayra taking the fruits because it knows that if it picks them now, it can eat them later? Or does it just work out that way? This type of future planning was thought to be limited to just apes and some birds. But now that they’ve discovered these unusual food storage techniques, biologists are starting to rethink that.

 Ragworm (7:54)


Even if the tayra is cognitively advanced, it’s hard to beat the tiny marine ragworm at the food storage game. Because these guys dabble in farming.

Ragworms live in beaches and estuaries, burrowing in sand and mud. Most of their food isn’t that nutritious — they’ll slurp up pretty much any organic material and scavenge for meals. But they’ll also pull cordgrass seeds into their tunnels.

At first, biologists thought the ragworms were just eating the seeds. But it turns out that they actually can’t eat them right away — they can’t get through the seeds’ thick husks. So instead, a ragworm will stick the seed in the sand, and a few weeks or months later, it sprouts into a little plant that the ragworm can eat. It’s like the worm version of a protein shake — a convenient, nutritious meal.

 Outro (8:30)


So whether they’re impaling their meals, spreading them out to dry, or biting heads off, animals have lots of ways to save their food for later. Even if they don’t have access to refrigerators or fancy preservatives.

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