August 25, 2023
by dave
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The scientific reason your cat loves tuna

Is it tuna? (Credit: FBenjr123, Wikimedia Commons)

Is it tuna? (Credit: FBenjr123, Wikimedia Commons)

Cat are known as finicky eaters, and my current fur babies are no exception. Iggy and Spud have turned their noses up at a variety of flavors in their two short years with us, but things finally clicked when we introduced them to premium tuna cat food. Suddenly it was all they wanted–and nothing else.

Iggy and Spud aren’t alone in their love of tuna. The dish is a staple of everything from New Yorker cartoons to Meow Mix jingles. And fish in general is such a hit with felines that an estimated 6% of all wild fish caught gets turned into moist cat food alone. That’s an odd diet for an animal that evolved in the desert.

Now researchers think they know why our feline friends have this curious craving. As I write in Science, researchers have discovered that cat taste buds contain the molecular machinery needed to detect umami. That’s the savory flavor of various meats, and one of the five basic tastes in addition to sweet, sour, salty, and bitter. But the feline palate isn’t just find tuned to meat–as one might expect for an obligate carnivore. The team of scientists also discovered that the cat’s umami receptor responds especially vigorously to molecules found in tuna. In taste tests, cats in the study preferred water flavored with these compounds over all other dishes. Tuna appears to hit the “umami sweet spot” in cats, as one of the researchers told me.

Still, it’s unclear why cats would have evolved a taste for tuna. It may have become a useful adaptation to living with humans. As far back as 1500 B.C.E., cats are depicted eating fish in the art of Ancient Egypt. And by the Middle Ages, felines in some Middle Eastern ports were consuming large quantities of fish—including tuna—likely because they were feasting on the scraps left by fishers. Cats that had a hankering for tuna likely had a leg up on their fish-averse comrades.

If your own cat doesn’t like tuna, don’t sweat it. Researchers have shown that cats aren’t able to tase sugar, but my cat Jasper used to love marshmallows, which are basically just sugar and more sugar. Some feline mysteries, it seems, can’t fully be explained by science.

June 6, 2023
by dave
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A birth control shot for cats?

Stray cats Amman, Jordan. (Credit: Alexey Komarov, Wikimedia Commons)

Stray cats Amman, Jordan. (Credit: Alexey Komarov, Wikimedia Commons)

Birth control for cats and dogs might sound like the setup for a joke, but it’s no laughing matter. There are more than 1.5 billion homeless dogs and cats in the world, suffering on the streets, being killed to stop the spread of rabies or protect wildlife, or getting euthanized in overcrowded shelters. Spay/neuter surgery can help keep pet numbers down–indeed it has made a massive impact on shelter euthanasia since the 1970s–but it’s too slow and too expensive to put a dent in the global overpopulation crisis.

That’s why scientists have been trying to come up with an alternative to the surgery for more than 20 years. They’ve been hoping to develop something like a shot or a pill–a one-time, permanent contraceptive that’s cheap and easy to administer. I wrote about these efforts in 2009, but nothing has worked–until now.

In a new study, researchers report a gene therapy approach that appears to contracept female cats for at least two years, and perhaps much longer.  The strategy delivers a gene for antimüllerian hormone, which is produced by follicles in the ovary that give rise to eggs. Cats that received the shot overproduced the hormone, which seems to disrupt the formation of their ovarian follicles, preventing ovulation. No cats given the shot became pregnant, despite spending lots of time with a willing male.

The study is small–there were only six treated cats and three controls–but experts say it’s by far the most promising progress they’ve seen towards the “holy grail” of pet contraception. If the approach proves safe and long-lasting (ideally permanent)–and if it works in dogs–it could truly revolutionize birth control for dogs and cats. No joking.

October 25, 2022
by dave
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‘Whooo’s a pretty kitty?’ Cats like it when we speak to them in baby talk

Jezebel has something to say. (Credit: David Grimm)

Jezebel has something to say. (Credit: David Grimm)

Cats, dogs, and babies have something in common–and it’s not just the mess they make. They all seem to elicit “baby talk” from us: short, repetitive phrases spoken with drawn-out syllables and a high pitch. If you’re a pet owner, you’re likely guilty of it–probably several times a day.

Scientists knew that dogs react to this “caregiver speech”, as it’s known. Or, as it’s known specifically for dogs, “dog-directed speech”. They’re far more likely to swivel their necks towards us or cock their heads. But no one had done a similar study on cats–until now.

As I write in Science, researchers have now tested whether our feline friends respond to “cat-directed speech”. They do, it turns out, though their reactions are more subtle than those of dogs. Their ears twitch towards us, or they momentarily stop bathing themselves. Cats, unlike dogs, also don’t respond to this type of talk from strangers; they only pay attention to their owners. That’s perhaps not a surprise as dogs are more likely to encounter unfamiliar humans, and are more likely to be cooed at by them.

But the work does reinforce the idea that cats, like dogs, are clued into the special bond we have with them: a bond that’s not unlike a mother has with her child. Perhaps that’s why cats also have evolved their own high-pitched sound, one embedded in their purrs that may evoke the attention-getting cries of human infants. We talk to our cats, but they also talk back.

September 20, 2022
by dave
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Wolves: Just how dog-like are they?

Me and a wolf named Wotan at Wolf Park. (Credit: Wolf Park)

Me and a wolf named Wotan at Wolf Park. (Credit: Wolf Park)

About 10 years ago, I visited one of the most unique sanctuaries in North America. I was reporting for my book, Citizen Canine–specifically a chapter about how the wolf became the dog. Experts agree that gray wolves gave rise to today’s dogs, but just how this happened is a mystery. Equally enigmatic is how much dogs changed over the course of this transformation. Did the ability to obey commands and follow human pointing arise only in dogs, for exampel? Or were flickers of these abilities present in their wolf ancestors? Ditto for the incredible bond between dogs and humans. Were wolves also capable of such attachment?

I had come to Wolf Park to find out just how different these two animals are. The sanctuary, 70 miles northwest of Indiana, is one of the few places in the world you can get up close and personal with wolves. I was lucky enough to spend some time face-to-face with the animals. As I write in my book:

When I enter the park, I’m directed to a safety training seminar. That’s my first clue that I’m not dealing with a domesticated animal. The second is the chain-linked fence topped with razor wire that separates the wolves from everyone else. As I walk along a dirt path that leads from the visitor’s center to the beige bunkhouse where the safety briefing will be held, I catch my first glimpse of a wolf. There, on the other side of the fence, stands a small black female, her eyes glowing yellow, her ears on alert. She’s staring at me, and not in a way that makes me feel comfortable. Despite what I’ve heard about the similarities between wolves and dogs, there’s nothing dog-like about this animal. She’s cold, she’s tense, and she clearly doesn’t want me here. 

Continue Reading →

July 28, 2022
by dave
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Can your dog read your mind?

(Credit: Hebrew Matio / Wikimedia Commons)

(Credit: Hebrew Matio / Wikimedia Commons)

You have a remarkable skill you’re probably not aware of: You can read other people’s minds. No, you’re not a telepath, but you do have a general sense of what someone else is thinking. If someone approaches you with a baseball in their hand for example, you can quickly deduce whether they mean to throw it to you–or bean you with it. You know their intentions, and you know that their thoughts are separate from your own.

This is a skill known as “Theory of Mind”. On it’s most basic level, it’s our ability to tune into the thoughts and intentions of others. Scientists have seen signs of Theory of Mind in non-human primates, birds, and even dogs, though the abilities in these animals don’t seem nearly as complex as they are in humans.

A new study provides a bit more evidence that our canine pals may have a rudimentary theory of mind. When a researcher offered a series of dogs a piece of sausage, but then either “clumsily” dropped the treat or snatched it away purposefully at the last second, the dogs were more likely to walk away in the latter instance. This suggests that dogs understand our intentions, as I write in a new article.

Pups also understand what we mean when we point at something–a skill some have also attributed to Theory of Mind.

Put together, the evidence is growing that our canine pals have some conception of what’s going on in our heads. That’s not terribly surprising–how else could they make sense of all of the seemingly strange and random things we do? After all, when you’ve lived with another species for about 20,000 years, it pays to have some sort of mind meld. No telepathy required.

May 31, 2022
by dave
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Shopping for a purebred dog? You may not get the personality you expect

A classic German Shepherd (Hans Kemperman, CC0, via Wikimedia Commons)

A classic German Shepherd (Hans Kemperman, CC0, via Wikimedia Commons)

Most modern breeds as we know them trace back less than 160 years. And yet the supposed personalities of these dogs feel like they have been engrained forever. Labrador retrievers are lovable and friendly. Border collies are neurotic and energetic. Chihuahuas are yappy. But things aren’t quite that straightforward, according to a new study that puts these temperaments to the test.

Researchers drew on data from thousands of dogs across the U.S., including genetics and owner surveys. As expected, most breeds have a defined look. When you shop for a German Shepherd, you’re going to get a tall canine with a bushy tail and pointy ears. But behaviors such as playfulness, trainability, and attachment to people varied widely, even within the same breed. The bottom line, says one of the study authors: If you’re looking for a dog with a specific personality, “you shouldn’t shop out of a catalog. Each dog is an individual.” (A website the team set up shows just how hard it is to know what you might get.)

Read more about this research in my latest story for Science. 

January 27, 2022
by dave
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Like your Yorkie? Thank a tiny genetic change that nearly vanished in ancient wolves

Barking up a big tree. (Credit: Ahmed Mateo, Wikimedia Commons)

Barking up a big tree. (Credit: Ahmed Mateo, Wikimedia Commons)

Dogs vary more in size than any other mammal on earth, from teacup-sized Chihuahuas to towering Great Danes. Most of this extreme variation has arisen over the past two centuries with the rise of modern dog breeding.  But Victorian dog fanciers didn’t create these breeds out of whole cloth, a new study finds. Instead, they hijacked two tiny genetic changes that have been present in the ancestors of dogs since at least the last Ice Age.  The study, which I cover this week in Science,  doesn’t just help explain why dogs are among the most malleable creatures on the planet. It may also elucidate how and why the sizes of wolves and their relatives have changed over evolutionary history.

October 22, 2021
by dave
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Where did dogs come from? Japanese wolf provides clues

A 19th-century sketch of the Japanese wolf. (Credit: Wikimedia Commons)

A 19th-century sketch of the Japanese wolf. (Credit: Wikimedia Commons)

Where and when did dogs arise? It’s one of the greatest mysteries of domestication, and one that remains unresolved despite decades of study.

Scientists know that all modern dogs descend from a population of gray wolves. But exactly who these wolves were and where they lived has been unclear. And thus, so has the origins of dogs.

Now, a new study of Japanese wolves may be providing some answers. This mysterious animal lived in Japan for thousands of years, but humans wiped it out about a century ago. In a new study, a team of Japanese researchers sequenced ancient DNA from nine Japanese wolves and 11 dogs, and compared them to the sequences of a variety of other canids. The data suggest that Japanese wolves are more closely related to dogs than are any other wolves. More importantly, the DNA suggests that the ancestor of the dog and the Japanese wolf was the same: A population of gray wolves that lived in East Asia, and which has likely vanished.

In all, the study suggests that dogs arose in East Asia, though the timing is still unclear. The location jibes with two proposed locations of dog domestication: Northeastern Siberia and Southeast Asia. It also seems to rule out a European or Middle Eastern origin, which some researchers had posited.

More work will be needed to seal the deal, and to say whether this is one canine case that’s finally been closed.

June 23, 2021
by dave
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Can the mysterious Chinese wildcat tell us anything about cat domestication?

The Chinese mountain cat. (Credit: ??????? - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=31346955)

The Chinese mountain cat. (Credit: https://commons.wikimedia.org/w/index.php?curid=31346955)

Unlike the ongoing mystery of where and when dogs arose, the history of cats is a less convoluted affair. Most scholars agree–based on both archaeological and genetic evidence–that domestic cats likely arose in the Middle East some 10,000 years ago.

Still, there have been hints that the cat story may not be as simple as it seems. In 2016, scientists reported evidence of a possible second domestication of cats–one that took place thousands of years later in China. Unlike the first cats, which descend from the African wildcat, these Asian kitties appear to have evolved from the leopard cat. Whatever happened, they didn’t last long; there’s no trace of them in today’s housecats. But the study did raise the intriguing possibility that cats may have been independently domesticated in Asia, as some argue happened with dogs.

New research appears to put that notion to rest. The largest genetic analysis of Chinese cats–including domestic cats, the Asiatic wildcat, and the mysterious Chinese mountain cat–finds that all domestic cats in the country are genetically indistinguishable from those elsewhere in the world. The researchers did find some Chinese mountain cat DNA in domestic cats, but that’s likely because the two have begun to interbreed as more and humans (and their cats) have shown up in the Tibetan Plateau–the realm of the Chinese mountain cat.

If the new study does have anything to say about domestic cats it’s that they may pose a threat to local wildcats. If domestic cat DNA begins to show up in the DNA of the Chinese mountain cat–an animal already considered vulnerable because of its low numbers and threats from humans–it could corrupt the genome of this unique creature, eventually scrubbing it from existence. A similar situation played out with the Scottish wildcat, which some now consider “functionally extinct” due to interbreeding with domestic cats.

Efforts are underway to save the Chinse mountain cats. But it remains to be seen if these felines will stand the test of time.

March 18, 2021
by dave
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Scientific mystery? Puppies to the rescue!

(Credit: Golden Trvs Gol twister, via Wikimedia Commons)

(Credit: Golden Trvs Gol twister, via Wikimedia Commons)

Point at an object, and, chances are, your dog will look at it. This seemingly simple ability–critical to our relationship with our canine companions–eludes most animals, including our closest relatives, chimpanzees. But it’s been hard to tell whether this skill is genetically hard-wired, or if dogs simply pick it up by hanging around us.

Scientists have now found a way to address the mystery–and it’s adorable. A team lead by Evan MacLean at the University of Arizona has borrowed nearly 400 Labrador and golden retriever puppies to show that the ability to understand finger pointing is indeed genetic. Working with the pups wasn’t easy, as MacLean told me: “It’s a balance between extraordinarily cute and rewarding moments, and frustration that leaves you at the brink of insanity. There is nothing that will not be chewed or peed on, including all of your research equipment, your clothes, and your body.”

But the researchers powered through, and the pups provided important answers. The team is now doing more sophisticated genetic analysis to determine exactly which genes may be responsible. In the meantime, be sure to check out the story for some adorable puppy pics, and a video as well.