Primates managed to keep most of their neurons the same size

Friday, August 10th, 2018

Eugène Dubois gathered the brain and body weights of several dozen animal species and calculated the mathematical rate at which brain size expands relative to body size:

Dubois reasoned that as body size increases, the brain must expand for reasons of neural housekeeping: Bigger animals should require more neurons just to keep up with the mounting chores of running a larger body. This increase in brain size would add nothing to intelligence, he believed. After all, a cow has a brain at least 200 times larger than a rat, but it doesn’t seem any smarter. But deviations from that mathematical line, Dubois thought, would reflect an animal’s intelligence. Species with bigger-than-predicted brains would be smarter than average, while those with smaller-than-predicted brains would be dumber. Dubois’s calculations suggested that his Java Man was indeed a smart cookie, with a relative brain size — and intelligence — that fell somewhere between modern humans and chimpanzees.

Dubois’s formula was later revised by other scientists, but his general approach, which came to be known as “allometric scaling,” persisted. More modern estimates have suggested that the mammalian brain mass increases by an exponent of two-thirds compared to body mass. So a dachshund, weighing roughly 27 times more than a squirrel, should have a brain about 9 times bigger — and in fact, it does. This concept of allometric scaling came to permeate the discussion of how brains relate to intelligence for the next hundred years.

Seeing this uniform relationship between body and brain mass, scientists developed a new measure called encephalization quotient (EQ). EQ is the ratio of a species’s actual brain mass to its predicted brain mass. It became a widely used shorthand for intelligence. As expected, humans led the pack with an EQ of 7.4 to 7.8, followed by other high achievers such as dolphins (about 5), chimpanzees (2.2 to 2.5), and squirrel monkeys (roughly 2.3). Dogs and cats fell in the middle of the pack, with EQs of around 1.0 to 1.2, while rats, rabbits, and oxen brought up the rear, with values of 0.4 to 0.5. This way of thinking about brains and intelligence has been “very, very dominant” for decades, says Evan MacLean, an evolutionary anthropologist at the University of Arizona in Tucson. “It’s sort of a fundamental insight.”

Comparative EQ

A century later, Suzana Herculano-Houzel found a (gruesome) way to count neurons efficiently:

An entire rat brain contains about 200 million nerve cells.

She looked at brains from five other rodents, from the 40-gram mouse to the 48-kilogram capybara (the largest rodent in the world, native to Herculano-Houzel’s home country of Brazil). Her results revealed that as brains get larger and heavier from one species of rodent to another, the number of neurons grows more slowly than the mass of the brain itself: A capybara’s brain is 190 times larger than a mouse’s, but it has only 22 times as many neurons.

Then in 2006, Herculano-Houzel got her hands on the brains of six primate species during a visit with Jon Kaas, a brain scientist at Vanderbilt University in Nashville, Tennessee. And this is where things got even more interesting.


As the primate brain expands from one species to another, the number of neurons rises quickly enough to keep pace with the growing brain size. This means that the neurons aren’t ballooning in size and taking up more space, as they do in rodents. Instead, they stay compact. An owl monkey, with a brain twice as large as a marmoset, actually has twice as many neurons — whereas doubling the size of a rodent brain often yields only 20 to 30 percent more neurons. And a macaque monkey, with a brain 11 times larger than a marmoset, has 10 times as many nerve cells.


The usual curse of an ever-expanding neuron size may stem from the basic fact that brains function as networks in which individual neurons send signals to one another. As brains get bigger, each nerve cell must stay connected with more and more other neurons. And in bigger brains, those other neurons are located farther and farther away.


A large rodent called an agouti has eight times as many cortical nerve cells as a mouse, while its white matter takes up an astonishing 77 times as much space. But a capuchin monkey, with eight times as many cortical neurons as a small primate called a galago, has only 11 times as much white matter.


Kaas thinks that primates managed to keep most of their neurons the same size by shifting the burden of long-distance communication onto a small subset of nerve cells. He points to microscopic studies showing that perhaps 1 percent of neurons do expand in big-brained primates: These are the neurons that gather information from huge numbers of nearby cells and send it to other neurons that are far away. Some of the axons that make these long-distance connections also get thicker; this allows time-sensitive information, such as a visual image of a rapidly moving predator, or prey, to reach its destination without delay. But less-urgent information — that is, most of it — is sent through slower, skinnier axons. So in primates, the average thickness of axons doesn’t increase, and less white matter is needed.

This pattern of keeping most connections local, and having only a few cells transmit information long-distance, had huge consequences for primate evolution. It didn’t merely allow primate brains to squeeze in more neurons. Kaas thinks that it also had a more profound effect: It actually changed how the brain does its work. Since most cells communicated only with nearby partners, these groups of neurons became cloistered into local neighborhoods. Neurons in each neighborhood worked on a specific task — and only the end result of that work was transmitted to other areas far away. In other words, the primate brain became more compartmentalized. And as these local areas increased in number, this organizational change allowed primates to evolve more and more cognitive abilities.

All mammal brains are divided into compartments, called “cortical areas,” that each contain a few million neurons. And each cortical area handles a specialized task: The visual system, for example, includes different areas for spotting the simple edges of shapes and for recognizing objects. Rodent brains don’t seem to become more compartmentalized as they get larger, says Kaas. Every rodent from the bite-sized mouse to the Doberman-sized capybara has about the same number of cortical areas — roughly 40. But primate brains are different. Small primates, such as galagos, have around 100 areas; marmosets have about 170, macaques about 270 — and humans around 360.

Humans can’t comprehend the magnitude of the insult that we pour into the ocean

Thursday, August 9th, 2018

What is it like to be a right whale? Not good:

They take their name from having been the “right” whale to hunt, because of the value of their blubber and baleen, and as such, they’d already been driven to rarity by the time of the American Revolution. Yet they do not die easy. The intentional killing of right whales was banned in 1935, but in March of that year, it took a group of fishermen — apparently not up to speed on international law — six hours, seven hand-thrown harpoons, and 150 rifle rounds to kill a 32-foot calf off Fort Lauderdale, Florida.

If right whales are threatened with extinction, it’s not from a lack of grit. It’s because their home — which spans 2,000 miles of coastline from southern Canada to northern Florida and cannot be described as small or niche — is one of the most human-modified and influenced regions on Earth. With due respect to Kraus, the North Atlantic right whale is not so much the urban whale as the Anthropocene whale.


One of the first people to start thinking about how we make whales miserable, as opposed to how we kill them, was the marine-acoustics scientist Chris Clark, now retired as a graduate professor of Cornell University. In the 1990s, with Cold War tensions subsiding, Clark was selected as the U.S. Navy’s marine-mammal scientist.

Using the Navy’s underwater listening posts, he was able to tune in to singing fin whales — second only to the blue whale in size — across a patch of sea larger than Oregon. In a data visualization he later created, the singing whales wink on and off: hotspots that arise, spread their sonic glow, and fade. Then enormous flares ripple across the entire space. That’s the acoustic imprint of a seismic air gun, used to probe for oil and gas deposits under the seafloor. “This was an epiphany,” Clark said. He had witnessed the way that human-made sounds could overwhelm, at enormous scales, whales’ ability to hear and be heard in the ocean.

I asked for his opinion about what day-to-day life is like for right whales now, two decades later. “Acoustic hell,” Clark replied. “Humans can’t comprehend the magnitude of the insult that we pour into the ocean.” While no one can say how an animal experiences its world, there are clues that Clark is correct. When the 9/11 attacks took place in 2001, researchers from the New England Aquarium happened to be in the Bay of Fundy, just across the U.S. border into Canada, testing right-whale feces for stress hormones. Over the following days, boat traffic abruptly dropped off. The scientists were struck by how clearly they could hear whale calls through their equipment, as though they’d been standing beside a freeway that fell silent and could suddenly hear birdsong. The whale stress levels measured in those quiet waters were the lowest by far that were recorded across four summers of sampling.

Noise his what biologists refer to as a “sublethal” impact, meaning it doesn’t directly cause death. The list of sub-lethal impacts has grown long, however. Right whales have the highest prevalence of infection with Giardia and Cryptosporidium, mainly from sewage and agricultural manure runoff, ever recorded in any mammal. In humans, these cause the diseases known as beaver fever and crypto, respectively, which involve debilitating digestive complaints. No one knows what problems, if any, they cause in right whales.

The whales are similarly exposed to an alphabet soup of chemicals (DDT, PCBs, PAHs, etc.), oil and gas, flame retardants, pharmaceuticals, pesticides — all the effluvia of civilization. Then there are blooms of red tide and other toxic algae, which can cause paralysis and death in humans, and are increasingly common. One study found paralytic shellfish poisoning in the feces of all 16 right whales it sampled. Again, no one can say what effect these pollutants might be having on right whales.


For an endangered species, a lack of births is a kind of death, and this year, for the first time since reliable record-keeping began nearly 30 years ago, no calves at all were born in the right-whale population. The animals’ welfare may now be so poor, their suffering so serious, that sublethal impacts have turned lethal.

We call them flying saltshakers of death

Wednesday, August 8th, 2018

Imagine emerging into the sun after 17 long years spent lying underground, Ed Yong suggests, only for your butt to fall off:

That ignominious fate regularly befalls America’s cicadas. These bugs spend their youth underground, feeding on roots. After 13 or 17 years of this, they synchronously erupt from the soil in plagues of biblical proportions for a few weeks of song and sex. But on their way out, some of them encounter the spores of a fungus called Massospora.

A week after these encounters, the hard panels of the cicadas’ abdomens slough off, revealing a strange white “plug.” That’s the fungus, which has grown throughout the insect, consumed its organs, and converted the rear third of its body into a mass of spores. The de-derriered insects go about their business as if nothing unusual has happened. And as they fly around, the spores rain down from their exposed backsides, landing on other cicadas and saturating the soil. “We call them flying saltshakers of death,” says Matt Kasson, who studies fungi at West Virginia University.

Massospora and its butt-eating powers were first discovered in the 19th century, but Kasson and his colleagues have only just shown that it has another secret: It doses its victims with mind-altering drugs. Perhaps that’s why “the cicadas walk around as if nothing’s wrong even though a third of their body has fallen off,” Kasson says.


Greg Boyce, a member of Kasson’s team, looked at all the chemicals found in the white fungal plugs of the various cicadas. And to his shock, he found that the banger-wings were loaded with psilocybin—the potent hallucinogen found in magic mushrooms. “At first, I thought: There’s absolutely no way,” he says. “It seemed impossible.” After all, no one has ever detected psilocybin in anything other than mushrooms, and those fungi have been evolving separately from Massospora for around 900 million years.

The surprises didn’t stop there. “I remember looking over at Greg one night and he had a strange look on his face,” Kasson recalls. “He said, ‘Have you ever heard of cathinone?’” Kasson hadn’t, but a quick search revealed that it’s an amphetamine. It had never been found in a fungus before. Indeed, it was known only from the khat plant that has long been chewed by people from the Middle East and the Horn of Africa. But apparently, cathinone is also produced by Massaspora as it infects periodical cicadas.


Infected cicadas behave strangely. Despite their horrific injuries, males become hyperactive and hypersexual. They frenetically try to mate with anything they can find, including with other males. They’ll even mimic the wing-flicking signals of females to lure males toward them. None of this does them any good—their genitals have either been devoured by the fungus or have fallen off with the rest of their butts. Instead, this behavior only benefits the fungus, allowing its spores to find new hosts.

Kasson suspects that cathinone and psilocybin are responsible for at least some of these behaviors. “If I had a limb amputated, I probably wouldn’t have a lot of pep in my step,” he said. “But these cicadas do. Something is giving them a bit more energy. The amphetamine could explain that.”

Psilocybin’s role is harder to explain. The drug might make humans hallucinate, but no one knows if cicadas would similarly trip. There is, however, a theory that magic mushrooms evolved psilocybin to reduce the appetites of insects that might compete with them for decaying wood. Perhaps by suppressing the appetites of cicadas, Massospora nudges them away from foraging and toward incessant mating.

There are many parasitic fungi that manipulate the behavior of insect hosts, including the famous Ophiocordyceps fungi, which can turn ants into zombies.

This is how a zombie outbreak could (semi-plausibly) happen.

You can learn a lot from humans and their stuff

Thursday, July 26th, 2018

You can learn a lot from humans and their stuff, it turns out:

Formal training programs, which can be called education, enhance cognition in human and nonhuman animals alike. However, even informal exposure to human contact in human environments can enhance cognition.

We review selected literature to compare animals’ behavior with objects among keas and great apes, the taxa that best allow systematic comparison of the behavior of wild animals with that of those in human environments such as homes, zoos, and rehabilitation centers.

In all cases, we find that animals in human environments do much more with objects. Following and expanding on the explanations of several previous authors, we propose that living in human environments and the opportunities to observe and manipulate human-made objects help to develop motor skills, embodied cognition, and the use of objects to extend cognition in the animals. Living in a human world also furnishes the animals with more time for such activities, in that the time needed for foraging for food is reduced, and furnishes opportunities for social learning, including emulation, an attempt to achieve the goals of a model, and program-level imitation, in which the imitator reproduces the organizational structure of goal-directed actions without necessarily copying all the details. All these factors let these animals learn about the affordances of many objects and make them better able to come up with solutions to physical problems.

The kea is a large parrot found in the mountains of the South Island of New Zealand — and it’s pretty freakin’ smart.

(Hat tip to Tyler Cowen.)

You never hear about a tiger laughing

Wednesday, May 16th, 2018

What’s the most interesting thing you’ve learned from personality psychology?” Tyler Cowen asks Bryan Caplan:

At least one thing that might be a good answer is that cheerfulness loads on extroversion.

There’s something actually very social about happiness. When you read this, it makes so much sense — how little of happiness seems to be about material possessions and how much of it is about having good relationships with other people.

You can think about animals. When I read you something about animals, the animals that laugh, they’re all social animals. Dogs laugh, chimpanzees laugh, humans laugh. You never hear about a tiger laughing, these very asocial animals. At least that’s one that I often do think about, is this connection between social interaction and being happy.

Dog training techniques work on children, too

Tuesday, April 17th, 2018

Dogs and children are surprisingly similar creatures:

Might dog training techniques then teach us something about parenting? Strictly speaking, this should work for human children up to age two to two-and-a-half, though so-called “super dogs” have mental abilities akin to a three-year-olds, says Stanley Coren, a professor emeritus of psychology at University of British Columbia and author of The Intelligence of Dogs.

“This works both emotionally and cognitively,” he tells Quartz, “so the techniques that will work for a two- or three-year-old child will work for a dog and vice versa.” By the time children reach age four or five, they begin to diverge from dogs by using language and intellect to reason things out.

Here are the recommended techniques (with edited-down descriptions):

Give them physical cues

Dogs require a consistent physical signal to focus their attention on a specific task or command. This is also true of human infants, who have been shown to learn better when prompted with social cues to direct their attention (for instance, turning our head or directing our gaze). “With children too,” Johnston tells Quartz, “it’s really important that you call their attention and signal to them that you’re trying to tell them something. Even infants are much more ready to learn when you use special cues.”

Know what they can and can’t handle

Typically children’s brains begin developing the capacity for self-control between the ages of 3 and 5, though the process continues until about age 11.

Dogs act out when their frontal lobes are over-worked. That’s why they chew up furniture or bark uncontrollably when left alone to simmer in their anxiety. This is also why young children throw tantrums at toy stores or while waiting for a meal at a restaurant.

“You figure how to engage him in an appropriate behavior before he engages in an inappropriate behavior.” In these situations, distracting a child before they act out is more effective than waiting to punish them.

Use positive reinforcement

In MRI scans of young children, neuroscientists found that negative reinforcement requires complicated reasoning that is difficult for their brains to grasp. In essence, small children fail to understand where they made the mistake. As they approach adolescence, though, negative reinforcement, which takes more complicated reasoning, becomes more effective, though scientists have yet to identify why this change in cognition occurs.

Model good behavior

Johnson recently conducted research at Yale University’s Canine Cognition Center that built on a previous Yale study of toddlers. In the previous study, the toddlers watched an adult run through a series of steps to open a puzzle box and get a prize. One of the steps was completely superfluous, yet the toddlers in the experiment did it anyway, without discriminating between what was necessary and what wasn’t. In Johnson’s study, dogs watched people go through steps to open a puzzle box and retrieve a treat. The people pulled one lever on the box that was irrelevant to the task. When dogs tried to solve the puzzle, they began to skip the lever step as soon as they learned to just open the lid instead.

Researchers believe that children meticulously repeat an adult’s sequence of steps because, unlike dogs, human socializing involves many behaviors that are not directly related to survival.

Run with their personality

“Kids are similar to dogs—at least before they can talk—because you can’t ask them questions. But you can ask them to make choices, and we can find out a lot about how they see the world when we use this method,” Hare, of the Dognition lab, says. “Some dogs are super communicative, while others might rely on their exceptional memories. You would teach these dogs in different ways, playing to their strengths.”

Guide them with calm, controlled authority

The rules vary based on a dog’s or child’s unique personality, but one thing must remain constant: the authority figure’s calmness and self-control.

An endearing antelope with a bulbous nose

Saturday, January 27th, 2018

The saiga is “an endearing antelope” that roams Central Asia. Its “bulbous nose gives it the comedic air of a Dr. Seuss character,” Ed Yong says:

It typically wanders over large tracts of Central Asian grassland, but every spring, tens of thousands of them gather in the same place to give birth. These calving aggregations should be joyous events, but the gathering in May 2015 became something far more sinister when 200,000 saiga just dropped dead. They did so without warning, over a matter of days, in gathering sites spread across 65,000 square miles — an area the size of Florida. Whatever killed them was thorough and merciless: Across a vast area, every last saiga perished.

Saiga calf

At first, the team suspected that a new infectious disease had spread through the population, but the pattern of deaths just didn’t fit. The saiga were dying too synchronously and too quickly. Also, all of them had died. “In biology, there’s certain rules, you know?” says Kock. “We accept that sometimes microbes can cause us harm, but not like this. Even very severe viral diseases or anthrax don’t do this. A good proportion of the animals would be fine.”

News of the die-off sparked outlandish explanations about Russian rocket fuel, radiation, and even aliens. But while conspiracy theories raged, a huge international team of scientists, led by Kock, got to work. Vets autopsied as many saigas as they could. Ecologists sampled the soil. Botanists checked the local plants. They couldn’t find any signs of toxins that might have killed the saiga. Instead, the actual culprit turned out to be a bacterium, one that’s usually harmless.

Pasteurella multocida normally lives in the saiga’s respiratory tract, but Kock’s team found that the microbe had found its way into the animals’ blood, and invaded their livers, kidneys, and spleens. Wherever it went, it produced toxins that destroyed the local cells, causing massive internal bleeding. Blood pooled around their organs, beneath their skin, and around their lungs. The saigas drowned in their own bodily fluids.

But that answer just led to more questions. Pasteurella is common and typically harmless part of the saiga’s microbiome. In livestock, it can cause disease when animals are stressed, as sometimes happens when they’re shipped over long distances in bad conditions. But it has never been linked to a mass die-off of the type that afflicted the saigas. What could have possibly turned this docile Jekyll into such a murderous Hyde?

The team considered a list of possible explanations that runs to 13 pages. They wondered if some environmental chemical or dietary change had set the microbe off. They checked if biting insects had transmitted a new infection that interacted with Pasteurella. They considered that Pasteurella might have gone rogue because of an accompanying viral infection, in the same way that Streptococcus bacteria can bloom during a cold, leading to strep throat. “We tested for everything and we couldn’t find anything,” says Eleanor Milner-Gulland from the University of Oxford.

Only one factor fit the bill: climate. The places where the saigas died in May 2015 were extremely warm and humid. In fact, humidity levels were the highest ever seen the region since records began in 1948. The same pattern held for two earlier, and much smaller, die-offs from 1981 and 1988. When the temperature gets really hot, and the air gets really wet, saiga die. Climate is the trigger, Pasteurella is the bullet.

It’s still unclear how heat and humidity turn Pasteurella into a killer, and the team is planning to sequence the bacterium’s genome to find out more.

None more black

Thursday, January 25th, 2018

Blackbirds, Ed Yong explains, aren’t actually all that black:

Their feathers absorb most of the visible light that hits them, but still reflect between 3 and 5 percent of it. For really black plumage, you need to travel to Papua New Guinea and track down the birds of paradise.

Although these birds are best known for their gaudy, kaleidoscopic colors, some species also have profoundly black feathers. The feathers ruthlessly swallow light and, with it, all hints of edge or contour. They make body parts seem less like parts of an actual animal and more like gaping voids in reality. They’re blacker than black. None more black.

By analyzing museum specimens, Dakota McCoy, from Harvard University, has discovered exactly how the birds achieving such deep blacks. It’s all in their feathers’ microscopic structure.

A typical bird feather has a central shaft called a rachis. Thin branches, or barbs, sprout from the rachis, and even thinner branches—barbules—sprout from the barbs. The whole arrangement is flat, with the rachis, barbs, and barbules all lying on the same plane. The super-black feathers of birds of paradise, meanwhile, look very different. Their barbules, instead of lying flat, curve upward. And instead of being smooth cylinders, they are studded in minuscule spikes. “It’s hard to describe,” says McCoy. “It’s like a little bottle brush or a piece of coral.”

Bird of Paradise Ultra-Black

These unique structures excel at capturing light. When light hits a normal feather, it finds a series of horizontal surfaces, and can easily bounce off. But when light hits a super-black feather, it finds a tangled mess of mostly vertical surfaces. Instead of being reflected away, it bounces repeatedly between the barbules and their spikes. With each bounce, a little more of it gets absorbed. Light loses itself within the feathers.

McCoy and her colleagues, including Teresa Feo from the National Museum of Natural History, showed that this light-trapping nanotechnology can absorb up to 99.95 percent of incoming light. That’s between 10 and 100 times better than the feathers of most other black birds, like crows or blackbirds. It’s also only just short of the blackest materials that humans have designed. Vantablack, an eerily black substance produced by the British company Surrey Nanosystems, can absorb 99.965 percent of incoming light. It consists of a forest of vertical carbon nanotubes that are “grown” at more than 750 degrees Fahrenheit. The birds of paradise mass-produce similar forests, using only biological materials, at body temperature.

Legendary was Hacienda Napoles where Pablo Escobar decreed his stately pleasure dome

Monday, January 22nd, 2018

I’m not sure what led Steve Sailer to cite a two-year-old National Geographic story about Pablo Escobar’s escaped hippos, but I immediately remembered the story from long, long ago (2003):

Legendary was Xanadu where Kubla Khan decreed his stately pleasure dome. Today, almost as legendary is Florida’s Xanadu…or Pablo Escobar’s 7,400-acre Hacienda Napoles.

Commenter Polearm noted that we nearly filled the United States with the great beasts at the beginning of the 20th Century:

America was withering under a serious meat shortage at the time. Beef prices had soared as rangeland had been ruined by overgrazing, and a crippled industry struggled to satisfy America’s explosively growing cities, an unceasing wave of immigrants, and a surging demand for meat abroad. There were more mouths to feed than ever, but the number of cows in the country had been dropping by millions of head a year. People whispered about the prospect of eating dogs. The seriousness of the Meat Question, and the failure to whip together some brave and industrious solution to it, was jarring the nation’s self-confidence and self-image. It was a troubling sign that maybe the country couldn’t keep growing as fast and recklessly as it had been. Maybe there were limits after all.

Now, though, someone had an answer. The answer was hippopotamuses. One Agricultural Department official estimated that an armada of free-range hippos, set moping through the bayous of Florida, Mississippi, and Louisiana, would easily yield a million tons of meat a year. Already, Representative Broussard had dispatched a field agent on a fact-finding mission. The man, a native of southern Africa, found the Louisiana swamps “wildly dismal and forbidding.” (The “silence strike[s] one with an almost unforgettable horror,” he wrote in his report, titled “Why and How to Place Hippopotamus in the Louisiana Lowlands.”) Still, the place was perfect for hippos. His conclusion: “The hippopotamus would find no difficulty living in Louisiana.”

Apparently, the animals tasted pretty good, too, especially the fatty brisket part, which could be cured into a delicacy that a supportive New York Times editorial was calling, euphemistically, “lake cow bacon.” (“Toughness is only skin deep,” another reporter noted.) Congressman Broussard’s office was receiving laudatory letters from ordinary citizens, commending his initiative-taking and ingenuity. Several volunteered to be part of the expedition to bring the great beasts back.

In other words, in the encroaching malaise of 1910, it was easy to be gripped by the brilliance of the hippopotamus scheme, to feel hippopotamuses resonating not just as a way of sidestepping catastrophic famine, but as a symbol of American greatness being renewed. Burnham’s generation had seen the railroad get synched across the wild landscape like a bridle and the near solid swarms of buffalo and passenger pigeons get erased. America had dynamited fish out of rivers, dredged waterways, felled and burned forests, and peeled silver from the raw wreckage of what had once been mountains. The frontier was now closed. So much had been accomplished and so much taken. It was clear that a once boundless-seeming land did have boundaries, and with those limits revealed, you couldn’t help but feel like you were drifting listlessly between them. There was a sense in the country of: Now what? And, lurking beneath that: What have we done?

Another commenter, the one they call Desanex, shared one of his favorite paintings, The Hippopotamus and Crocodile Hunt by Peter Paul Rubens:

The Hippopotamus and Crocodile Hunt by Peter Paul Rubens

Too many cypress knees

Saturday, January 13th, 2018

Swamp Park, in southeastern North Carolina, is at the northern extreme for American alligators, which means it can get a little cold for the cold-blooded reptiles:

At first, [George Howard, the park’s general manager] thought the water had too many cypress knees – woody projections from tree roots that are a common sight in swamps.

Then he saw teeth.

Alligator Snout Poking out of Ice

When it’s cold but not icy, the alligators disappear, sinking to the bottom of the swamp for most of the day or burrowing into the mud, Howard said. “You don’t see them, but they’re under there.”


Right before the surface freezes, they stick their snouts out of the water so they can continue breathing.

Iguanas, by the way, react somewhat differently to the cold:

And in Florida, where temperatures took a rare dip into the 40s last week, iguanas also slowed their bodily functions. But because many are tree dwellers, some just fell to the ground.

It was a repeat of a cold snap in 2010, when the iguana situation caught people similarly unawares.

“Neighbourhoods resounded with the thud of iguanas dropping from trees onto patios and pool decks, reptilian Popsicles that suggested the species may not be able to retain its claw-hold on South Florida,” the Sun-Sentinel’s David Fleshler wrote.

But the story had a happy ending, Fleshler reported. The iguanas “have rebounded, repopulating South Florida neighbourhoods and resuming their consumption of expensive landscaping.”

By the way, the term brumation was coined in 1965, so reptiles could have their own term for hibernation.

Yes, dolphins are smart

Friday, January 12th, 2018

The more we study dolphins, the brighter they turn out to be:

At the Institute for Marine Mammal Studies in Mississippi, Kelly the dolphin has built up quite a reputation. All the dolphins at the institute are trained to hold onto any litter that falls into their pools until they see a trainer, when they can trade the litter for fish. In this way, the dolphins help to keep their pools clean.

Kelly has taken this task one step further. When people drop paper into the water she hides it under a rock at the bottom of the pool. The next time a trainer passes, she goes down to the rock and tears off a piece of paper to give to the trainer. After a fish reward, she goes back down, tears off another piece of paper, gets another fish, and so on. This behaviour is interesting because it shows that Kelly has a sense of the future and delays gratification. She has realised that a big piece of paper gets the same reward as a small piece and so delivers only small pieces to keep the extra food coming. She has, in effect, trained the humans.

Her cunning has not stopped there. One day, when a gull flew into her pool, she grabbed it, waited for the trainers and then gave it to them. It was a large bird and so the trainers gave her lots of fish. This seemed to give Kelly a new idea. The next time she was fed, instead of eating the last fish, she took it to the bottom of the pool and hid it under the rock where she had been hiding the paper. When no trainers were present, she brought the fish to the surface and used it to lure the gulls, which she would catch to get even more fish. After mastering this lucrative strategy, she taught her calf, who taught other calves, and so gull-baiting has become a hot game among the dolphins.

Dolphins are clever in the wild, too:

In an estuary off the coast of Brazil, tucuxi dolphins are regularly seen capturing fish by “tail whacking”. They flick a fish up to 9 metres with their tail flukes and then pick the stunned prey from the water surface. Peale’s dolphins in the Straits of Magellan off Patagonia forage in kelp beds, use the seaweed to disguise their approach and cut off the fishes’ escape route. In Galveston Bay, Texas, certain female bottlenose dolphins and their young follow shrimp boats. The dolphins swim into the shrimp nets to take live fish and then wriggle out again – a skill requiring expertise to avoid entanglement in the fishing nets.

Dolphins can also use tools to solve problems. Scientists have observed a dolphin coaxing a reluctant moray eel out of its crevice by killing a scorpion fish and using its spiny body to poke at the eel. Off the western coast of Australia, bottlenose dolphins place sponges over their snouts, which protects them from the spines of stonefish and stingrays as they forage over shallow seabeds.

This earns a “wow”:

At a dolphinarium, a person standing by the pool’s window noticed that a dolphin calf was watching him. When he released a puff of smoke from his cigarette, the dolphin immediately swam off to her mother, returned and released a mouthful of milk, causing a similar effect to the cigarette smoke.

Their ability to learn a language is impressive:

By human definition, there is currently no evidence that dolphins have a language. But we’ve barely begun to record all their sounds and body signals let alone try to decipher them. At Kewalo Basin Marine Laboratory in Hawaii, Lou Herman and his team set about testing a dolphin’s ability to comprehend our language. They developed a sign language to communicate with the dolphins, and the results were remarkable. Not only do the dolphins understand the meaning of individual words, they also understand the significance of word order in a sentence. (One of their star dolphins, Akeakamai, has learned a vocabulary of more than 60 words and can understand more than 2,000 sentences.) Particularly impressive is the dolphins’ relaxed attitude when new sentences are introduced. For example, the dolphins generally responded correctly to “touch the frisbee with your tail and then jump over it”. This has the characteristics of true understanding, not rigid training.

I’m reminded of that damn bird, Alex the African Grey parrot, who was no birdbrain, and of Rico the Border Collie.

Raptors are setting fires on purpose

Thursday, January 11th, 2018

Raptors — the black kite, whistling kite, and brown falcon — are intentionally spreading grass fires in northern Australia:

Raptors on at least four continents have been observed for decades on the edge of big flames, waiting out scurrying rodents and reptiles or picking through their barbecued remains.

What’s new, at least in the academic literature, is the idea that birds might be intentionally spreading fires themselves. If true, the finding suggests that birds, like humans, have learned to use fire as a tool and as a weapon.

Gosford, a lawyer turned ethno-ornithologist (he studies the relationship between aboriginal peoples and birds), has been chasing the arson hawk story for years. “My interest was first piqued by a report in a book published in 1964 by an Aboriginal man called Phillip Roberts in the Roper River area in the Northern Territory, that gave an account of a thing that he’d seen in the bush, a bird picking up a stick from a fire front and carrying it and dropping it on to unburnt grass,” he told ABC.

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“MJ,” a Kimberley, (Western Australia) cattle station caretaker manager … saw kites working together to move a late dry season fire across a river by picking up, transporting, and dropping small, burning sticks in grass, which immediately ignited in several places,” they write. “The experience resulted in an uncontrollable blaze that destroyed part of the station’s infrastructure.”

Bob White, a firefighter in the Northern Territory saw a small group of raptors, likely black kites, “pick up numerous smouldering sticks and transport them ahead of a fire front, successfully helping the blaze spread up a small valley.”

Nathan Ferguson claims to have observed fire spreading about a dozen times in the Northern Territory since 2001. The long-time firefighter is adamant that the birds he’s observed — picking up twigs and starting new fires — were doing so on purpose.

That jibes with the other research Gosford and Bonta dug up. “Most accounts and traditions unequivocally indicate intentionality on the part of three raptor species,” they wrote.

Dogs are not super-cooperative wolves

Tuesday, October 24th, 2017

Dogs are not super-cooperative wolves:

She and her colleagues challenged their canines to a simple task, which other scientists have used on all kinds of brainy animals — chimps, monkeys, parrots, ravens, and even elephants. There’s a food-bearing tray that lies on the other side of their cage, tempting and inaccessible. A string is threaded through rings on the tray, and both of its ends lie within reach of the animals. If an individual grabs an end and pulls, it would just yank the string out and end up with a mouthful of fibers — not food. But if two animals pull on the ends together, the tray slides close, and they get to eat.

All in all, the dogs did terribly. Just one out of eight pairs managed to pull the tray across, and only once out of dozens of trials. By contrast, five out of seven wolf pairs succeeded, on anywhere between 3 and 56 percent of their attempts. Even after the team trained the animals, the dogs still failed, and the wolves still outshone them. “We imagined that we would find some differences but we didn’t expect them to be quite so strong,” Marshall-Pescini says.

It’s not that the dogs were uninterested: They explored the strings as frequently as the wolves did. But the wolves would explore the apparatus together — biting, pawing, scratching, and eventually pulling on it. The dogs did not. They tolerated each other’s presence, but they were much less likely to engage with the task at the same time, which is why they almost never succeeded.

“The dogs are really trying to avoid conflict over what they see as a resource,” says Marshall-Pescini. “This is what we found in food-sharing studies, where the dominant animal would take the food and the subordinate wouldn’t even try to approach. With wolves, there’s a lot of arguing and it sounds aggressive, but they end up sharing. They have really different strategies in situations of potential conflict. [With the dogs], you see that if you avoid the other individual, you avoid conflict, but you can’t cooperate either.”

“Amazingly, no one had ever studied whether carnivores could solve this type of cooperative task, and it’s fun to see that the wolves coordinated,” says Brian Hare from Duke University, who studies dog behavior and the influence of domestication. He has argued that during the domestication process, dogs began using their traditional inherited mental skills with a new social partner: humans.

Simultaneously, dogs perhaps became less attentive to each other, adds Marshall-Pescini. After all, wolves need to work together to kill large prey, and sharing food helps to keep their social bonds intact. But when they started scavenging on human refuse, they could feed themselves on smaller portions by working alone. If they encountered another forager, “maybe the best strategy was to continue searching rather than to get into conflict with another dog,” she says.

But dogs can be trained. When owners raise dogs in the same household, and train them not to fight over resources, the animals start to tolerate each other, and unlock their ancient wolflike skills. This might be why, in 2014, Ljerka Ostojic, from the University of Cambridge, found that pet dogs, which had been trained in search and rescue, had no trouble with the string-pulling task that flummoxed Marshall-Pescini’s dogs.

“It speaks to the fact that living among other dogs, without interaction with humans, is arguably less natural for dogs — as if domestication both refined attention, coordination, and even pro-sociality between species, and weakened social skills within the species,” says Alexandra Horowitz, who studies dog cognition at Barnard College. “A pack of dogs living together, without human intervention, is impaired compared to dogs living with humans.”

Being bitten by an Australian tiger snake is a wholly unpleasant experience

Saturday, September 2nd, 2017

Being bitten by an Australian tiger snake is a wholly unpleasant experience:

Within minutes, you start to feel pain in your neck and lower extremities — symptoms that are soon followed by tingling sensations, numbness, and profuse sweating. Breathing starts to become difficult, paralysis sets in, and if left untreated, you’ll probably die. Remarkably, the venom responsible for these horrifying symptoms has remained the same for 10 million years — the result of a fortuitous mutation that makes it practically impossible for evolution to find a counter-solution.


The secret to tiger snake venom has to do with its biological target — a clotting protein called prothrombin. This critically important protein is responsible for healthy blood clotting, and it exists across a diverse array of animal species (humans included). Any changes to this protein and the way it works can be catastrophic to an animal, leading to life-threatening conditions such as hemophilia. It’s this vulnerable target that makes the tiger venom so potent, but at the same time, animals are under intense evolutionary pressure to maintain prothrombin in its default, functional state. As Fry explained in a release, if the animals had any variation in their blood clotting proteins, “they would die because they would not be able to stop bleeding.”

Non-permissive even to motorcycles

Monday, August 7th, 2017

American special operations forces famously found themselves riding to war on horseback in Afghanistan in 2001:

When the 5th Special Forces Group’s Operational Detachment Alpha 595 touched down and linked up with warlord Abdul Rashid Dostum — a Soviet-trained ethnic Uzbek military officer who had sided with the Northern Alliance against the predominantly Pashtun Taliban and who ultimately became a highly controversial figure accused of multiple human rights abuses and war crimes — they found his forces already conducting cavalry raids on horseback due to the lack of roads and even established trails in the area.

“Looking back, it was the best means for travel because some of those places we went would have been non-permissive to even motorcycles,” retired U.S. Air Force combat controller Bart Decker, who had served attached to ODA 595, said in 2016.

“It was the wild, wild west,” U.S. Air Force Maj. Mike Sciortino, another former combat controller, who was then serving with the 31st Surgical Operations Squadron, added at the time. “When we first got in, they said we were probably going to ride horses … I had never ridden a horse before. I was like, are these guys serious?”

ODA 595 and Northern Alliance on Horseback in 2001

The whole situation might have been a disaster had it not be for an amazing twist of fate. ODA 595’s commanding officer, U.S. Army Major Mark Nutsch, had grown up on a cattle ranch in Kansas and competed in rodeo events while he studied at Kansas State University. “The guys did a phenomenal job learning how to ride that rugged terrain,” he said in a later interview. “Initially you had a different horse for every move … and you’d have a different one, different gait or just willingness to follow the commands of the rider. … The guys had to work through all of that and use less than optimal gear. … Eventually we got the same pool of horses we were using regularly.”