"Once we started looking, we saw it everywhere."

January 7, 2025 10:44 AM

"The study, led by the University of Wisconsin-Eau Claire and the University of California, Davis, is the first to chronicle widespread carnivorous behavior among squirrels." More about this long-term squirrel study.
posted by jessamyn (32 comments total)

Does this count as a double?
posted by fight or flight at 10:52 AM on January 7 [5 favorites]

I read the title of the first article to my partner, who has a degree in animal behavior, and their reaction was middling: “Yeah, most people don’t know how many species are opportunistic carnivores.” Basically, they weren’t super impressed.

Then I read the subheading and they stopped me and said, “Wait, wait—they HUNT? Carnivorous squirrels is one thing, PREDATORY squirrels is completely another. I’m obsessed.”

I have to agree that while squirrels eating meat is eyebrow raising, squirrels hunting and killing for their meat is on entirely another level of cool. It appeals greatly to the Redwall child in me.
posted by brook horse at 11:08 AM on January 7 [7 favorites]

Ah yes the Kill Squirrels of Caerbannog.
posted by alex_skazat at 11:11 AM on January 7 [5 favorites]

The dogs have been trying to warn us all along!
posted by Greg_Ace at 11:12 AM on January 7 [24 favorites]

/r/SEUT vindicated after all these years ...
(it stands for Squirrels Eating Unusual Things, btw, and it's on reddit)
posted by scruss at 11:40 AM on January 7 [4 favorites]

This definitely puts the Marvel superhero named Squirrel Girl in a new light.
posted by Brandon Blatcher at 11:46 AM on January 7 [4 favorites]

Note that these are California ground squirrels, a species that is not particularly widespread. They live in burrows underground; they're a regular presence in the Western Neighborhoods of SF.
posted by billjings at 11:47 AM on January 7 [1 favorite]

“Yeah, most people don’t know how many species are opportunistic carnivores.”

Rabbits are too, right?
posted by any portmanteau in a storm at 11:51 AM on January 7 [2 favorites]

I knew it
posted by tiny frying pan at 12:00 PM on January 7 [1 favorite]

Mice and chickens will both eat meat. I think bovines and equines have been known to do it sort of by the way - eating bugs on plants.
posted by Lawn Beaver at 12:10 PM on January 7

LET THEM FIGHT
posted by wenestvedt at 12:26 PM on January 7 [2 favorites]

Think of all the rodents that eat their own babies!!! Stress-induced carnivores.
posted by Lawn Beaver at 12:32 PM on January 7

In German folk lore [Eurasian] squirrels are understood to be cunning egg thieves, with a distinct sense that it's best not to dwell on the fate of the hypothetical fledgling if you want to keep being enchanted by their antics. Good advice, still enchanted.
posted by Ashenmote at 12:43 PM on January 7 [1 favorite]

The photos of the squirrels are really good! Dr. Sonja Wild from UC Davis has some other wildlife photography on her site, including the squirrels in less bloodthirsty moments, and some canoodling puffins.
posted by hovey at 1:03 PM on January 7 [1 favorite]

I briefly read that as “…among students,” and I thought “oh, great. Spring Semester is going to be something.” I wasn’t even surprised.
posted by GenjiandProust at 2:02 PM on January 7 [1 favorite]

C.S.U.D.
posted by AlSweigart at 2:02 PM on January 7 [4 favorites]

I think bovines and equines have been known to do it sort of by the way - eating bugs on plants.

I'm not sure about meat, but I know someone whose horse learned to steal and eat chicken eggs.
posted by Birds, snakes, and aeroplanes at 2:35 PM on January 7 [2 favorites]

Cows, at least some of them, will eat chicks if they come across a ground nest while grazing. Protein is expensive to make and valuable to steal.
posted by tavella at 2:47 PM on January 7 [1 favorite]

would you rather be eaten by one squirrel-sized horse or by forty horse-sized squirrels?
posted by chavenet at 3:01 PM on January 7 [12 favorites]

you didn't mess with the squirrels, Morty tell me you didn't mess with the squirrels
posted by Sebmojo at 3:25 PM on January 7 [2 favorites]

I'm noticed a few squirrels in my neighborhood starting to wear a shoulder holster.
posted by clavdivs at 3:34 PM on January 7 [3 favorites]

Yeah, most people don’t know how many species are opportunistic carnivores

Yo, blood meals are very nutrious to animals, very quick conversion to energy.

The Vampire Bat is probsbly one end of a spectru, right? the fact that there are animals that only eat blood, it prompts the question--how often are blood meals / meat scavenging happening, in general?

I think my biological world was flipped in school, when I saw butterflies sipping on a bloodied carcass in the forest.

Vampire Butterflies.

This became a seed of.my thesis in grad school. Vegetarian fish will become fish eaters during Shrimping season, when Shrimpers kill a lot of fish and throw them overboard.

I processed 23,000 fish killed as bycatch in 30 odd trawls. Tens of thousands of fish killed by the Shrimping fleet in a night, but only one of my fish ever showed signs of rotting. Those fish carcasses are being eaten quickly after the fishers throw them back.
posted by eustatic at 3:41 PM on January 7 [5 favorites]

I’ve read that completely obligatory herbivores are much, much rarer than we tend to think - most herbivores can and will chow down on a hunk of meat if they can’t get enough vegetation to survive. You can find some pretty metal pictures of deer engaged in opportunistic cannibalism if you care to look.
posted by showbiz_liz at 4:09 PM on January 7

Mice and chickens will both eat meat.

For that matter, both mice and chickens actively hunt, too. Emily Dennis is doing some wicked cool stuff on how lab mice learn to hunt and eat crickets in naturalistic foraging environments. And there's an entire chicken breed (the Buckeye) with the very specific reputation of being excellent mousers...

(Rats are also known hunters, and will specifically happily hunt and kill mice to the extent that I think they're more effective at stressing mice out than cats are.)
posted by sciatrix at 4:10 PM on January 7

Ah, it's ground squirrels rather than tree squirrels! I find myself kind of curious about the opportunities available to, say, grey squirrels now. Surely they don't pass up unattended nestlings—

A literature review and field observations indicate that most sciurids are facultative predators on small vertebrates. This behavior is documented for at least 30 sciurid species in 8 genera. The frequency of predation apparently is influenced by various factors including climate, season, gender, reproductive condition, and availability of plant sources for certain nutrients such as calcium and nitrogen. Although sciurids assimilate as much energy from animal foods as do obligate carnivores, behavior associated with predation appears to be less efficient in sciurids and may rely partly on prey habituation and other adaptive behaviors.

.... yeah, that tracks too...
posted by sciatrix at 4:18 PM on January 7

Chickens were never herbivores, rather omnivores, insects are perhaps their favorite food. And the difference between a large insect and a mouse aren't much.
posted by tavella at 4:21 PM on January 7 [2 favorites]

would you rather be eaten by one squirrel-sized horse or by forty horse-sized squirrels?

The AI says 40 horses dead, 40 and eight and 40 horses find a new home

my uncle spent 2 days in 1944 Germany in a 40 and 8.

The 40th// National Cowboy Poetry Gathering
"A horse tougher then me"

I take the 40 horse sized squirrels on a rolling track of 40 40 and 8s.
because by the end, I'm going to have a horse whisperer notion of a festival of raccoon cowboys or wind up in the cheeks of Sunset.
posted by clavdivs at 5:03 PM on January 7 [1 favorite]

Yeah, that's awesome work. The genuinely fascinating thing isn't the predation here so much as the seamless way that the ground squirrel population adopted the behavior at relatively high frequencies in response to the sudden glut of voles. That's the coolest part of this study: more than just documenting the existence of this counterintuitive behavior, these groups really go above and beyond to document the prevalence of that behavior across many individuals so that they can estimate which animals (and how many) are hunting, and how that impacts any social dynamics in space use. The speed of the way that many animals adapted very quickly to dense vole prey availability says some cool things about the ability of the ground squirrel brain to react to unexpected opportunity. And that opens up all kinds of interesting mechanistic questions about how easy the behavior is to learn and for which animals. If you're very lucky, this is the kind of thing that can sustain a few different labs teasing out individual variation, parental teaching, etc. This is so cool!
posted by sciatrix at 5:04 PM on January 7 [5 favorites]

When I was a boy I would spend my time watching the animals in our heavily forested property - especially the squirrels. We had several species, eastern grays and fox squirrels, the rare flying squirrel of the night, even the many-lined ground squirrels.
And we had endless chipmunks and ubiquitous red squirrels.
My father would hunt the red squirrels with terrifying determination. "Squirrel rounds" were rat-shot - a .22 caliber round filled with lead metallic sand. He would use a .410 if there were still leaves on the trees.
My mother said "it's how he was raised." She told me the red squirrels damaged the house and I was content with this answer.

That was the summer when I saw a red squirrel eating a decapitated chipmunk.
It was like something out of a terrifying fever dream, or an episode of Liquid Television. Like a Bakshi cartoon in real life.

The red squirrel sat on a stump, holding the decapitated body of the chipmunk in its paws like a limp bag of potatoes, gorging itself from within the chest cavity. The blood looked black on the face of the creature.

I told my father and he nodded. "They castrate the other squirrels."
I asked what he meant.
He said, "when you see a red squirrel attacking a gray, the red squirrel crawls all over it until it can get into a position where it can bite off the other squirrel's testicles."

There are a few moments in childhood where the world rotates around you, like a compass reorienting itself, as though magnetic north has suddenly shifted and everything realigns itself according to some new, fundamental understanding of reality.

That was the year I received my first firearm, also a .410. My father didn't hunt deer or turkey like the other men in my family (Vietnam ruined him on killing most animals) but he taught me how to safely handle the gun. And he told me that I would track every animal I wounded to a terminal end and that I would eat every single animal I killed. "Except for one."
"Except for one," I replied.

And I shot a lot of red squirrels. "Because they damage the house," I told my mother.

Last week, thirty years later - nearly two decades after my father's untimely death - I was at my mom's house celebrating my step-dad's birthday. "Find candles," she said. I pulled open a junk drawer near the back porch as it seemed as likely a place as any to find candles for a cake. I reached into the back of the drawer and pulled out a handful of the detritus of five decades.

I felt something small and square, roughly the size of a box of small birthday candles. I opened my hand only to discover a box of .22 caliber rifle rounds. There they had remained, in the back of the drawer nearest the porch where he would stand shouldering the Winchester 72, the click and crack of the action and report indicating the finality of his careful actions.

There is a great deal that happens in the woods that humans are entirely unaware of. I still shoot and hunt and eat meat and I spend a great deal of time in the woods, vacillating between Herzog's terror and despair and Muir's ecstasy and wonder. But I will never forget the image of a small squirrel devouring an even smaller chipmunk and the secret that my father and I shared. Not a hatred of the thing, but a quiet understanding that there are simply many things that most people don't know. I don't hate red squirrels. But it is also true that the real nature of a creature can remain entirely hidden from the eyes of most human beings. The horrors are often confounded by matters of scale.
There are monsters in the woods.
posted by Baby_Balrog at 7:12 PM on January 7 [11 favorites]

Nature, red in tiny tooth and claw
posted by Greg_Ace at 7:20 PM on January 7 [2 favorites]

On the man-bites-dog flipside of squirrels eating mammals we have a mammals eating squirrels story here in Ireland. Our red squirrel Sciuris vulgaris is not the same as the American red squirrel Tamiasciurus hudsonicus but the grey squirrel Sciurus carolinensis is the same; having been introduced from North America via England to Ireland in 1911. The larger greys out-competed the native squirrel nutkins across much of the island.

But over the last 20 years, the reds are back in town country because of a resurgence of pine marten Martes martes in the midlands. The greys haven't a clue w.r.t. to martens whereas reds have been co-existing with that predator for 000s of years. A recent study from QUB applied marten-smell to feeding locations and reports that reds avoided such feeders after treatment whereas greys didn't etc. To the nearest whole percent we know nothing about the web of eating interactions in the natural world but clearly metaphorical swings and roundabouts are involved.
posted by BobTheScientist at 1:11 AM on January 9 [2 favorites]

I was seeing bits of that while I was furiously reading, Bob! What I find really cool about it is that American martens do also exist... but the American marten's range happens to barely overlap with the Eastern grey squirrel's, and the Pacific marten is entirely allopatric, so there has been no time to adapt to marten predation for grey squirrels.

Idly, I wonder if the reason we don't have so many martens in eastern North America is the presence of grey fox as our historically dominant arboreal terrestrial mesopredator.

(and on the dog-bites-squirrel flipside, apparently free-roaming and feral dogs are the predator that at least three other squirrel species are least adapted to, at least in terms of circadian rhythms, relative to longer-term native predators of squirrels.)
posted by sciatrix at 12:00 PM on January 9 [1 favorite]