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Animals & Wildlife

Why have we domesticated some animals but not others? It comes down to four F's.

An entertaining video explains why we can't ride zebras or breed "war bears."

Photo credit: Canva

Horses were domesticated over 5,000 years ago. Zebras, never.

Humans have domesticated several kinds of animals over the millennia, from trusty horses and mules to livestock for milk and meat to our favorite furry companions. But why those specific animals and not others? What is it that led us to those particular choices? Why can we ride horses but not zebras? Why don't we purposefully breed "war bears" to fight for us?

That last question comes straight from the always-interesting and often-hilarious CGP Grey, whose YouTube videos explore all kinds of things we wonder about but don't necessarily take the time to research. In the video "Why Some Animals Can't Be Domesticated," Grey explains the four main elements that make an animal a good candidate for domestication, which excludes bears (and many others) from the list.

Grey alliterated the four elements to make them easier to remember: Friendly, Feedable, Fecund, and Family-Friendly. Let's dig into what those mean.

- YouTubewww.youtube.com

Domestication requirement #1: Friendly

This one is fairly self-explanatory, but basically an animal has to not post an inherent, immediate threat. We have to be able to catch them if we're going to domesticate them, so that eliminates all of the "carnivores whose day job is murder" as Grey puts it, as well as the large, nervous prey animals that are too afraid of us to let us get anywhere near them.

wild animals, domesticated animals, gazelleGood luck trying to catch a gazelle.Photo credit: Canva

Domestication requirement #2: Feedable

Every animals is feedable, of course, but that doesn't mean it's easy or cheap to feed them, especially in large numbers. This category pretty much eliminates pure carnivores and some omnivores, leaving mostly herbivores (and some unpicky omnivores) that are easy and cheap to feed. And that aren't dangerous (see #1).

wild animals, domesticated animals, chickens, chicken feedChickens will eat just about anything.Photo credit: Canva

Domestication requirement #3: Fecund

This requirement is all about breeding and babies. Some animals are extremely slow to breed, like pandas and elephants, making them undesirable candidates for domestication. Animals that have mate frequently and have relatively short gestation times and/or large litters are more suited to domesticated life. They also need to grow up quickly, which also takes elephants out of the pool.

However, as Grey points out, humans can still tame other animals like elephants. But taming is not the same as domesticating. The basic rule is: If it's on a farm, it's domesticated. If it's in a circus, it's tamed.

Domestication requirement #4: Family-friendly

This is where the horses and zebras question comes in. Horses were domesticated in Eurasia, but if humans started in Africa, why weren't zebras domesticated first? Grey explains that while horses tend to live in hierarchical herds, zebra are more independent with no family structure. Humans can capture the lead male horse and get the rest of the herd to fall in line. Zebra herds are more of a free-for-all and they're kind of jerks to even one another.

horses, zebras, domesticated animals, wild animalsThere's actually a big difference between horses and zebras besides just the stripes.Photo credit: Canva

Barnyard animals have inherent family structures that humans have figured out how to fit into. These animals learn to see the humans who own them as a lead cow or top chicken or whatever.

Way back in the hunter-gatherer age, when humans were just figuring out animal domestication, animals had to have all four of these requirements. Today, we have the ability and technology to domesticate more animals if we want to, but we also have less of a need to. Some breeds of foxes have recently been domesticated, bred to be friendly with humans. How fun would it be to have a pet fox?

- YouTubewww.youtube.com

Technically, a lot more animals could be domesticated if people really wanted to put in multiple human lifetimes of time and effort, but why?

You can follow CGP Grey on YouTube for more fun and informative videos.

This article originally appeared in April.

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Science

A scientist created a 'utopia' for mice and then they all started dying

The results are fascinating, but are they relevant to humanity?

Canva Photos

How could Mouse Heaven go so terribly wrong?

In 1968 John Calhoun, a scientist and animal behavioralist, decided to create a "utopia" for mice. It would have unlimited food and water, with beautiful nesting spaces and plenty of materials for the mice to make cozy homes with. Sweet experiment! the mice were probably thinking. Much better than the Maybelline trials we're used to.

However, there was a catch, of course. There was one thing the utopia would be lacking, and that would be physical space. As the mouse population grew, overcrowding would become an issue, and Calhoun wanted to study the problems this would potentially cause. That sound you hear is the collective sigh of the disappointed mice who were stoked about the 24/7 all-you-can-eat buffet.

The experiment, dubbed Universe 25, began when Calhoun introduced four mouse "couples" into the utopian complex. A year or so later, it was overrun and the conditions had turned hellish, even though the mice had not run out of food or water.

mouse, mice, animals, science, research, studies"The conditions had turned WHAT?"Giphy

Initially, for just the eight original mice, the square box Calhoun built included 256 nesting boxes (or apartments) stacked on top of one another. Water bottles and food dispensers were located all along the nesting spots, and mice could travel throughout the complex at will via mesh tunnels. The starter mice were also screened for diseases and the population was obviously protected from predators. The climate was controlled and comfortable. Conditions were perfect.

The first mouse pups showed up a little over three months later, with the population of the colony doubling every 55 days. Nineteen months later, there were 2200 mice living inside the box. With such perfect surroundings, the infant mortality rate was practically zero, leading to the rapid rise in numbers.

mice, mouse experiments, scientific research, animal experiments, overpopulationJohn Calhoun poses with his rodents inside the mouse utopia.Yoichi R Okamoto, Public Domain


By month 19, this rodent utopia had become an overcrowded hellscape. Calhoun noticed three alarming trends, in particular.

In short, everything was devolving into chaos and the very society of the mice began to collapse at a rapid rate.

The "Beautiful Ones" and the "Dropouts": Mice have a complex social hierarchy ruled by dominant alpha males. Sam Kean of Science History Institute Museum & Library notes that, in the wild, non-dominant males (the ones who lose macho showdowns) can skip town and start over somewhere else. But in the close quarters of Calhoun's experiment, with nowhere to hide, they were forced to hang around and viciously battle with each other over scraps. Eventually, non-dominant male mice, which Calhoun called the "Beautiful Ones," withdrew from society completely and only ate, slept, and groomed themselves.

Though resources were unlimited, certain aggressive males hoarded them anyway: The alpha males ruled over everything in the once-utopian mouse society. They kept harems of females in the apartments to mate with and fought fiercely to defend their territory. But new waves of hungry young male mice kept coming and coming, and eventually even the most dominant alphas abandoned their posts. This led to more attacks on nursing females, which in turn led to more mothers kicking their pups out of the nest early.

Birth rate declined dramatically: With the non-dominant males giving up completely and focusing on #SelfCare, dominant males too exhausted from endless battles, and females sick and tired of it all (many became asexual hermits by the end), stopped mating and giving birth entirely. Once this happened, the society was doomed. Even with plenty of food still available, cannibalism was rampant.

Calhoun was not shy about drawing parallels between his research and humanity. "I shall largely speak of mice, but my thoughts are on man, on healing, on life and its evolution," he once wrote.


mice, mouse experiments, scientific studies, universe 25, sociology, overpopulationAlpha male mice, anyone? Photo by Kanashi on Unsplash

There are aspects of his wild experiment that certainly sound familiar.

We live in a world with plenty of resources for everyone, but a few select people hoard more than their fair share. When you think of the rodent "apartments," it's hard not to picture densely packed urban environments where people are stacked on top of each other at every turn. Maybe on some level some of us can relate to the “Beautiful Ones” and their urge to not participate in all the ugliness and just sequester and groom themselves. You can make an argument that when the mice stopped having to worry about food and shelter, it removed the element of challenge from their lives and left them lost–like many of us are lucky enough to not have to wonder where our next meal comes from, and maybe that has something to do with our never-ending search for meaning. Some even go so far as to link more people choosing to delay having children, or not have children at all, with the collapsing society of the mice.

But Calhoun's work has also been heavily scrutinized, with some claiming it's based on shaky science. And in the end, there’s the small matter that humans are not mice. We are infinitely more complicated, and so much better suited to adapting to our environments. Kean writes, "Ultimately Calhoun’s work functions like a Rorschach blot—people see what they want to see."

It's fascinating and thought-provoking nonetheless.

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Pets

Service dog sees his favorite character on a Disney cruise and utterly loses his cool

Pure. Joy.

Photo credit: Canva

Service dogs deserve vacations, too.

Service dogs are professionals who are trained to be attentive, helpful and extremely well-behaved for their owners who rely on them for everyday living. They aren't easily distracted and have solid control over their impulses because their job performance is vital to humans who need them. No one wants a service dog going rogue.

But underneath all of that self-control and professionalism, service dogs are still dogs, as an adorable reunion on a Disney cruise ship makes delightfully clear.

Ashton McGrady is a content creator who shares her adventures with her Golden Retriever service dog, Forest, who has an affinity for Disney characters. In one video, she shows Forest choosing his own stuffy at a Disney gift shop, even putting the money on the counter to pay for it himself. But another video of Forest being reunited with his favorite character, Pluto, has people the world over feeling his joy vicariously.

Watch:

@radiantlygolden

proof that distance won’t keep the very best of friends apart ❤️🚢✨ we love you pluto!!! #servicedog #servicedogteam #disneytiktok #disneycruiseline #disneycruise #hostedbydisney

Ashton calls Forest her "best pal and lifesaver," and it's clear from her videos that they make a great team. People loved seeing the good doggo get to let loose and enjoy a romp with Pluto and how the cast member interacted with him as well.

"Those dogs are such good pups and work so hard to keep their owners safe, it’s nice to see them play for a bit ❤️"

"This is the most golden retriever golden I’ve ever seen 🥰🥰🥰"

"i just know the actor under the costume was having the best day ever."

"DID PLUTO WAG HIS OWN TAIL??? This is the best thing I’ve seen all day"

"It's like the Disney hug rule applies to dogs...but it's play with them until they are done."

The "Disney hug rule" referenced here is an apparently unofficial "rule" that DIsney cast members when dressed in character don't end a child's hug until the child let's go—basically letting the child hug the character as long as they want to. It's not an actual rule, but it's a thoughtful practice some cast members use to make sure their young guests don't leave a character meet disappointed.

For Forest, the equivalent is playing until he (or his owner—he's on the job, after all) decides he's done.

This isn't the first time Forest has had a touching reunion with Pluto. Ashton shared another video with a similar interaction—it's clear that Pluto truly is Forest's bestie.

@radiantlygolden

I just want to go back to this moment 🥹 if you’re friends with pluto and you see this, you made our entire day ♥️ #waltdisneyworld #wdw50 #epcotfestivalofthearts #festivalofthearts #epcot #charactermeetandgreet #disneytiktok #distok #servicedog #servicedogteam #servicedogsatdisney


Ashton also uses social media to educate people about service dogs, as there are a lot of misunderstandings out there about what service animals are, how they work, and where they are allowed to be.

Though service dogs and their owners will often naturally form a bond, a service dog is not a pet; it's a working animal that assists a person with disabilities or health conditions. In fact, service animals are considered medical equipment, in the same category as a wheelchair or an oxygen tank, and they are allowed to go anywhere the person they are serving would normally be allowed to go—even if other animals are not allowed. As the Americans with Disabilities Act website states: "Under the ADA, State and local governments, businesses, and nonprofit organizations that serve the public generally must allow service animals to accompany people with disabilities in all areas of the facility where the public is allowed to go."

Service dogs are sometimes confused with emotional support animals, but they are not the same thing. Service animals are trained to do specific tasks related to mitigating a person's disability, which could range from recognizing when their owner is needing medical attention to reminding them to take a medication to guiding them around an obstacle or across a street.

@radiantlygolden

If a business is not pet-friendly, they may only ask these TWO questions! note: “emotional support” is NOT considered a valid answer to question 2. thank you @Disney Parks for this great example of how it should be done. #servicedog #servicedoglife #servicedogteam #disabilitytiktok #disneyparks

There are some guidelines and laws that govern how the general public as well as private businesses should interact with service animals. First, no one should pet a service animal unless their handler specifically invites them to. Second, there are only two questions a business owner or their staff members are allowed to ask a person with a service dog: 1) Is the dog a service animal who is required because of a disability? And 2) What work or task has the dog been trained to perform? They are not allowed to ask for documentation, ask what disability the person has or ask that the dog demonstrate what they can do.

For people who need them, service animals like Forest are a vital part of living a full life. They are also working professionals who deserve a break now and then, so it's fun to see this good doggo having the time of his life with his buddy, Pluto.

You can follow Ashton on TikTok and YouTube.

This article originally appeared in January

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London man finds a mysterious egg, incubates it, and launches a Pixar-worthy journey of love

When Riyadh found an abandoned egg, he had no idea that it would change his life.

Courtesy of Riyadh Khalaf/Instagram (used with permission)

When Riyadh found an egg, he had no idea how much it would change his life.

The story of Riyadh and Spike starts like the opening to a children's book: "One day, a man was walking along and spotted a lone egg where an egg should not have been…" And between that beginning and the story's mostly sweet ending is a beautiful journey of curiosity, care, and connection that has captivated people all over the world.

Irish author Riyadh Khalaf was out walking in Devon, England, when he came upon an egg. "We just found what we think is a duck egg," Riyadh says in a video showing the milky white egg sitting in a pile of dirt. "Just sitting here on its own. No nest. No other eggs."

Thinking there was no way it was going to survive on its own, Riyadh put the egg in a paper cup cushioned with a napkin and took it home to London, which entailed two car rides, a hotel stay, a train ride, a tube ride, and a bus ride. He said he used to breed chickens and pigeons, so he had some experience with birds. Knowing the egg could survive for a while in a dormant state, he ordered an incubator on Amazon, and the journey to see if the egg was viable began.


Even though it was "just an egg," Riyadh quickly became attached, and once it showed signs of life he took on the role of "duck dad." Every day, the egg showed a drastic change in development, and Riyadh's giddy joy at each new discovery—movement, a discernible eye, a beak outline—was palpable. He devoured information on ducks to learn as much as he could about the baby he was (hopefully) about to hatch and care for.

Finally, 28 days later, the shell of the egg began to crack. "I could see this very clear outline of the most gorgeous little round bill," Riyadh said—confirmation that it was, indeed, a duck as he had suspected. But duckling hatching is a process, and one they have to do it on their own. Ducklings instinctively know to turn the egg as it hatches so that the umbilical cord detaches, and the whole process can take up to 48 hours. Riyadh watched and monitored until he finally fell asleep, but at 4:51am, 29 hours after the egg had started to hatch, he awakened to the sound of tweets.

"There was just this little wet alien staring back at me," he said. "It was love at first sight."

Riyadh named his rescue duckling Spike. Once Spike was ready to leave the incubator, he moved into "Duckingham Palace," a setup with all of the things he would need to grow into a healthy, self-sufficient duck—including things that contribute to his mental health. (Apparently ducklings can die from poor mental health, which can happen when they don't have other ducks to interact with—who knew?)

"My son shall not only survive, but he shall thrive!" declared the proud papa.

Riyadh knew it would be impossible for Spike to not imprint on him somewhat, but he didn't want him to see him as his mother. Riyadh set up mirrors so that Spike could see another duckling (even though it was just himself) and used a surrogate stuffed duck to teach him how to do things like eat food with his beak. He used a duck whistle and hid his face from Spike while feeding him, and he played duck sounds on his computer to accustom Spike to the sounds of his species.

"It's just such a fulfilling process to watch a small being learn," said Riyadh.

As Spike grew, Riyadh took him to the park to get him accustomed to the outdoors and gave him opportunities to swim in a small bath. He learned to forage and do all the things a duck needs to do. Throughout, Riyadh made sure that Spike was getting the proper balanced nutrition he needed as well. Check this out:


After 89 days, the day finally came for Spike to leave Riyadh's care and be integrated into a community of his kind "to learn how to properly be a duck." A rehabilitation center welcomed him in and he joined a flock in an open-air facility where he would be able to choose whether to stay or to leave once he became accustomed to flying. Within a few weeks of being at the rehabilitation center, his signature mallard colors developed, marking his transition from adolescence. Spike has been thriving with his flock, and Riyadh was even able to share video of his first flight.

This is the where "And they all lived happily ever after" would be a fitting end to the story, but unfortunately, Spike and his fowl friends are living in trying times. The rehabilitation center was notified by the U.K. government in December of 2024 that the duck flock needed to be kept indoors for the time being to protect them from a bird flu outbreak and keep it from spreading.

Building an entire building for a flock of ducks is not a simple or cheap task, so Riyadh called on his community of "daunties" and "duncles" who had been following Spike's story to help with a fundraiser to build a "Duckingham Palace" for the whole flock. Riyadh's followers quickly raised over £11,000, which made a huge difference for the center's owners to be able to protect Spike and his friends.

All in all, Riyadh and Spike's story is a testament to what can happen when people genuinely care. If Riyadh had left that egg where it was, it may not have made it. If Spike hadn't survived and been moved to the rehab center, the ducks there would be in greater danger of the bird flu due to the costs of building an indoor shelter for them. Despite the ongoing bird flu threat, the story really does have a happy ending.

Thank to Riyadh for sharing Spike's journey with us. (You can follow Riyadh on Instagram here.)

This article originally appeared in January.

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