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.”

Chimps are not superhumanly strong

Wednesday, June 28th, 2017

Chimps are not as superhumanly strong as we thought they were:

“There’s this idea out there that chimpanzees are superhuman strong,” says Matthew O’Neill at the University of Arizona in Phoenix. Yet his team’s experiments and computer models show that a chimpanzee muscle is only about a third stronger than a human one of the same size.

This result matches well with the few tests that have been done, which suggest that when it comes to pulling and jumping, chimps are about 1.5 times as strong as humans relative to their body mass. But because they are lighter than the average person, humans can actually outperform them in absolute terms, say O’Neill.

His findings suggest that other apes have similar muscle strength to chimpanzees. “Humans are the odd ones,” he says.

O’Neill’s team has been studying the evolution of upright walking. To create an accurate computer model of how chimps walk, the researchers needed to find out whether their muscles really are exceptionally strong. So they removed small samples of leg muscle from three chimps under general anaesthetic and measured the strength of individual fibres.

The same procedure is used to study human muscles. Comparing the results with the many studies on those revealed that, contrary to the claims of several other studies, there is nothing special about chimp muscle. “Chimpanzee muscle is really no different than human muscle in terms of the force that individual fibres exert,” says O’Neill.

So why, on a pound-for-pound basis, are chimps slightly stronger than humans? The team went on to look at the muscle of chimps that had died of natural causes, which revealed that two-thirds of their muscle consists of fast-twitch fibres, whereas more than half of human fibres are slow-twitch.

[...]

Quite how the myth that chimps are incredibly strong came about is not clear, says O’Neill. But it may have been fuelled by a 1923 study that claimed one chimp could pull nine times its own body weight. Later studies suggested they could only pull two to four times their weight.

A parable of the lessons that can emerge from unfettered science

Tuesday, May 16th, 2017

I was immediately fascinated by the Siberian farm fox experiment and the surprisingly broad domestication phenotype, which notably includes pigmentation.

Marlene Zuk reviews Dugatkin and Trut’s How to Tame a Fox (and Build a Dog) for The New York Times, and ends on this note:

The book, however, is not only about dogs, or foxes, or even science under siege from political interests. It is an exploration of how genes, evolution and then environment shape behavior, and in a way that puts paid simplistic arguments about nature versus nurture. It may serve — particularly now — as a parable of the lessons that can emerge from unfettered science, if we have the courage to let it unfold.

Marlene Zuk wrote Paleofantasy: What Evolution Really Tells Us About Sex, Diet and How We Live.

Researchers find yet another reason why naked mole-rats are weird

Wednesday, May 3rd, 2017

Researchers find yet another reason why naked mole-rats are weird:

For example, instead of generating their own heat, they regulate body temperature by moving to warmer or cooler tunnels, which lowers the amount of energy they need to survive. They’re also known to have what Park calls “sticky hemoglobin,” which allows them to draw oxygen out of very thin air. And because they live underground in large social groups, they’re used to breathing air that’s low in oxygen and high in carbon dioxide.

[...]

To start out, he and his colleagues tested how well the mole-rats fared in a chamber with only 5 percent oxygen, which is about a quarter of the oxygen in the air we breathe, and can kill a mouse in less than 15 minutes.

They watched closely, ready to pull the mole-rats out at the first sign of trouble.

“So we put them in the chamber and after five minutes, nothing. No problems,” Park says. An hour later, there were still no problems.

Five hours later, the researchers were tired and hungry and ready to go home, but the mole-rats could’ve kept chugging along.

“Oh, I think so,” says Park. “They had more stamina than the researchers.”

The animals had slowed down a bit, he says, but were awake, walking around and even socializing.

“They looked completely fine,” he says.

Next, the researchers decided to see how the mole-rats dealt with zero percent oxygen.

“And that was a surprise, too,” he says.

Such conditions can kill a mouse in 45 seconds.

The four mole-rats involved in this leg of the study passed out after about 30 seconds, but their hearts kept beating and — a full 18 minutes later — the mole-rats woke up and resumed life as usual when they were re-exposed to normal air. (The three mole-rats that were exposed for 30 minutes, however, died.)

[...]

When the researchers looked at tissue samples taken from the mole-rats at various times during the oxygen deprivation, they noticed a spike in levels of another sugar, fructose, about 10 minutes in.

“We weren’t looking for it, but bang, fructose goes way up in the blood and then it goes way up in the organs and it gets used by heart and brain,” Park says.

The naked mole-rats appear to have the option of switching fuels from glucose, which requires oxygen to create energy, to fructose, which doesn’t.

Humans are capable of storing and using fructose in the liver and kidney, but as Park explains, we don’t have enough of the correct enzyme to create energy directly from fructose. Nor do we have enough of the proteins necessary to move fructose molecules into the cells of vital organs. Our cells have to convert it into glucose in order to use it.

The cells in the brain, heart, liver and lungs of naked mole-rats are all outfitted with proteins that moves fructose into the cells, and with the right enzyme to create energy from it.

“They have a social structure like insects, they’re cold-blooded like reptiles, and now we found that they use fructose like a plant,” Park says.

No sci-fi alien is as strange as an octopus

Tuesday, May 2nd, 2017

“No sci-fi alien is so startlingly strange” as an octopus, Sy Montgomery noted, but they’re even stranger than we realized:

Rosenthal and Eisenberg found that RNA editing is especially rife in the neurons of cephalopods. They use it to re-code genes that are important for their nervous systems — the genes that, as Rosenthal says, “make a nerve cell a nerve cell.” And only the intelligent coleoid cephalopods — octopuses, squid, and cuttlefish — do so. The relatively dumber nautiluses do not. “Humans don’t have this. Monkeys don’t. Nothing has this except the coleoids,” says Rosenthal.

It’s impossible to say if their prolific use of RNA editing is responsible for their alien intellect, but “that would definitely be my guess,” says Noa Liscovitch-Brauer, a member of Rosenthal’s team who spearheaded the new study. “It makes for a very compelling hypothesis in my eyes.”

[...]

Only about 3 percent of human genes are ever edited in this way, and the changes are usually restricted to the parts of RNA that are cut out and discarded. To the extent that it happens, it doesn’t seem to be adaptive.

In cephalopods, it’s a different story. Back in 2015, Rosenthal and Eisenberg discovered that RNA editing has gone wild in the longfin inshore squid — a foot-long animal that’s commonly used in neuroscience research. While a typical mammal edits its RNA at just a few hundred sites, the squid was making some 57,000 such edits. These changes weren’t happening in discarded sections of RNA, but in the ones that actually go towards building proteins — the so-called coding regions. They were ten times more common in the squid’s neurons than in its other tissues, and they disproportionately affected proteins involved in its nervous system.

Having been surprised by one cephalopod, the team decided to study others. Liscovitch-Brauer focused on the common cuttlefish, common octopus, and two-spot octopus. All of these showed signs of extensive RNA editing with between 80,000 to 130,000 editing sites each. By contrast, the nautilus — a ancient cephalopod known for its hard, spiral shell — only had 1,000 such sites.

This distinction is crucial. The nautiluses belong to the earliest lineage of cephalopods, which diverged from the others between 350 and 480 million years ago. They’ve stayed much the same ever since. They have simple brains and unremarkable behavior, and they leave their RNA largely unedited. Meanwhile, the other cephalopods — the coleoids — came to use RNA editing extensively, and while evolving complex brains and extraordinary behavior. Coincidence?

Liscovitch-Brauer also found that around 1,000 of the edited locations were shared between the coleoid species — far more than the 25 or so sites that are shared between humans and other mammals. These sites have been preserved over hundreds of millions of years of evolution.

No invertebrate on land would have been a match for it

Friday, March 10th, 2017

The earliest tetrapods had much bigger eyes than their fishy forebears, and those bigger eyes evolved before walking legs:

Eyes don’t fossilize, but you can estimate how big they would have been by measuring the eye sockets of a fossilized skull. MacIver and his colleagues, including fossil eye expert Lars Schmitz, did this for the skulls of 59 species — from finned fish to intermediate fishapods to legged tetrapods. They showed that over 12 million years, the group’s eyes nearly tripled in size. Why?

Eyes are expensive organs: it takes a lot of energy to maintain them, and even more so if they’re big. If a fish is paying those costs, the eyes must provide some kind of benefit. It seems intuitive that bigger eyes let you see better or further, but MacIver’s team found otherwise. By simulating the kinds of shallow freshwater environments where their fossil species lived — day to night, clear to murky — they showed that bigger eyes make precious little difference underwater. But once those animals started peeking out above the waterline, everything changed. In the air, a bigger eye can see 10 times further than it could underwater, and scan an area that’s 5 million times bigger.

In the air, it’s also easier for a big eye to pay for itself. A predator with short-range vision has to constantly move about to search the zone immediately in front of its face. But bigger-eyes species could spot prey at a distance, and recoup the energy they would otherwise have spent on foraging. “Long-range vision gives you a free lunch,” says MacIver. “You can just look around, instead of moving to inspect somewhere else.”

Tiktaalik with Eyes Above Surface

Those early hunters would have seen plenty of appetizing prey. Centipedes and millipedes had colonized the land millions of years before, and had never encountered fishapod predators. “I imagine guys like Tiktaalik lurking there like a crocodile, waiting for a giant millipede to walk by, and chomping on it,” says MacIver. “No invertebrate on land would have been a match for it.”

Monarch miscalculation

Tuesday, February 28th, 2017

It looks like a scientific error about butterflies has persisted for more than 40 years:

A few years ago, Christopher Hamm was reading up on monarch butterflies when he noticed something peculiar. All of the scientific articles that mentioned the number of the insect’s chromosomes — 30, it seemed — referenced a 2004 paper, which in turn cited a 1975 paper. But when Hamm, then a postdoc at the University of Kansas in Lawrence, did a genetic analysis of his own, he found that his monarchs only had 28 chromosomes, suggesting that an error has pervaded the literature for more than 40 years. Another twist, however, was just around the corner.

Hamm suspected a mistake when he read the original 1975 paper. The authors, biologists N. Nageswara Rao and A. S. Murty at Andhra University in Visakhapatnam, India, had studied what they claimed was an Indian monarch butterfly in their work. But there’s a problem: Monarchs are nearly exclusively a North American species. “It’s implied they just went outside their building and collected some butterflies,” Hamm says. “I immediately thought, ‘Monarch butterflies in India? Really?’”

Sure monarchs are master travelers, with the longest-known seasonal migration of any insect. And it’s not uncommon for a few to get blown off course to Australia, the Philippines, the United Kingdom, and a handful of other places from time to time. But ending up as far away as India seemed like a stretch. Hamm, now a data scientist at Monsanto in Woodland, California, also knew that taxonomists since Carl Linnaeus have struggled to distinguish species in Lepidoptera, the order of insects to which monarchs belong. For example, the monarch (Danaus plexippus) and a similar-looking butterfly known as the common tiger butterfly (D. genutia) were thought to be the same for more than a century until they were reclassified as separate species in 1954. And guess what: D. genutia lives in India.

Common Tiger Butterfly and Monarch Butterfly

Hamm thinks that Rao and Murty, perhaps not knowing about the reclassification, netted bugs they assumed were monarchs but were actually common tiger butterflies. Back in the lab, they performed a technique known as a chromosome squash — squeezing the butterflies’ cells between thin films of glass until individual chromosomes are visible under a microscope — counted to 30, and published the results. Then, in 2004, Brazilian zoologist Keith Brown Jr. cited the work in his own research exploring the evolutionary history of butterflies; he never suspected that Rao and Murty might have been working with a misidentified species. Brown’s paper has been cited a dozen times since, and the idea that monarchs have 30 chromosomes is now well established in the literature.

They can fight off a wolf and then come home and be polite

Friday, February 24th, 2017

In the highland steppes of Sivas province in central Turkey, the Kangal dog is a local icon:

The huge, sand-colored breed is named after a town in the southern Sivas province, where Kangals emerged as a distinct breed about 6,000 years ago. Kangals can grow to about 145 pounds and up to 33 inches tall, surpassing most other massive dog breeds like Great Danes. Today, in Turkey and increasingly in the United States, the viciously protective dogs are known and celebrated as wolf fighters.

[...]

The dogs boast an intimidating size, a thick coat that protects against bites, and fearlessness—they’re capable of killing a wolf but sometimes the sight of a Kangal alone is enough to scare large predators away.

Kangal Dogs

The shepherds whistle and shout all the time at the sheep, directing them this way and that, but it’s not common for the Kangals to face anywhere in the direction of the flock. Their heads are always pointed towards the horizon or the nearest hillside; they are always on watch. When we load into an SUV at the end of a bitterly cold day, they’re still looking out into the distance with no desire to turn in.

Ranchers in the U.S. are now starting to take interest in Kangals. Breeders in western Montana have imported the dogs since 2009, and 20 Kangals were imported from Turkey in 2014 for a joint research program on wolf predation by the U.S. Department of Agriculture and U.S. Fish and Wildlife Service. Jan Dohner, the vice president of the Kangal Dog Club of America, says there’s been substantial interest in the dogs recently, “especially as livestock raisers search for nonlethal methods of large predator control.”

The dogs have been paired with farmers since they can guard against bears and wolves, but they get along with people. And they’re tough, too—able to work through windy winters and dry, hot summers. For Vose Babcock, whose cattle ranch is situated outside Missoula, Kangals are the perfect dog for rural living. “They’re good with house guests and baby livestock, but don’t like thieves.”

The sight of the huge, watchful dogs may become more common on American ranches in the coming years—the USDA will continue to breed the dogs imported in 2014. Babcock sees no downside: “They can fight off a wolf, mountain lion, or bear and then come home and be polite with grandparents and grandchildren.”

A Hotel California for Apex Predators

Monday, February 20th, 2017

P-45, the King of Malibu, is a hundred-and-fifty-pound male mountain lion:

After killing an alpaca at a Malibu winery in late 2015, he was captured and fitted with a G.P.S. collar by the National Park Service, which designated him the forty-fifth subject in a long-running study, led by a wildlife ecologist named Seth Riley, on the mountain lions of Los Angeles. (The “P” comes from Puma concolor, the species whose common names include puma, panther, catamount, cougar, and mountain lion.) Since P-45 was collared, according to Phillips, he has killed some sixty goats, sheep, llamas, and alpacas, a miniature horse, and a four-hundred-and-fifty-pound heifer: members of the class of rustic pet known as “hobby animals.” Gallingly, he has eaten little — a nibble of heart meat here, a nip of scrotum there. Except in the case of pygmy goats, for which he has a taste, he seems to kill for sport.

Rickards, who has short blond hair and a cheerful manner, grew up on the ranch and runs a cat rescue there. She and Phillips have horses and dogs and, until recently, had alpacas. Then one night P-45 jumped into the alpaca pen, killing two of them. When it happened again last spring, and three more died, Phillips gave away the rest of the herd and turned his attention to pursuing the culprit. To Phillips, P-45 is a sociopath, a freak — “the John Wayne Gacy of mountain lions.”

Mountain Lion P-45

The Santa Monica Mountains extend from the Pacific Coast through the Hollywood Hills, to end in Griffith Park. Urban though Los Angeles is, its mountains are furrowed with densely vegetated canyons full of deer and coyotes, cactuses, live oaks, wheeling hawks — a patchwork of public and private holdings claimed both by top carnivores and by their human counterparts.

The real estate is increasingly contested. At some two hundred and forty square miles, the range is the perfect size for one or two dominant males and several females, along with their young. The National Park Service study is currently tracking ten mountain lions in the area, including three breeding males. There is also an unknown number of uncollared lions. Living at such close quarters intensifies the lions’ natural territorialism; in this population, the leading cause of death is conflict with other lions. But adolescent lions who set out in search of their own hunting grounds often come to an impasse. The range is bounded by the Pacific Ocean to the south and the Hollywood Freeway (the 101) to the north, and bisected by the 405 between Brentwood and Bel Air. Just as the roads keep native lions in, they also keep outside lions from entering, and first-order inbreeding has become common. Lush but confined, the mountains are a cushy prison, a Hotel California for apex predators, whose future is threatened by a double deficiency: not enough space for a group of lions with not enough genetic differences among them.

As a result, the mountain-lion population in the Santa Monica Mountains is in danger of entering an extinction vortex, a downward spiral in which everything starts to fail. “They could be in the process of genetic flatlining,” Robert Wayne, an evolutionary biologist at the University of California, Los Angeles, says. “Without our assistance, the Santa Monica Mountain pumas are likely to go extinct.” This is what nearly happened to the Florida panthers, in the mid-nineties, when intensive inbreeding caused physical changes that hindered reproduction. According to Riley, who recently published a paper on the subject, if similar problems occur and no new lions enter the area the likelihood of L.A.’s lions disappearing in fifty years is 99.7 per cent. But genetic rescue can come in the form of just one new animal in each generation — in Florida, where the population was larger, it took just six females from Texas to reverse the spiral.

From this point of view, Los Angeles can’t spare a single cat, and certainly not one matching P-45’s profile. According to a preliminary genetic analysis done at Wayne’s lab, P-45 comes from north of the 101: he is an outsider, a lion who successfully navigated the freeway and miles of suburbs to introduce his precious DNA to the Santa Monicas. Under threat, P-45 has inspired a committed following. In November, an editorial in the Los Angeles Times titled “Save P-45” defended his behavior as entirely natural. “Killing P-45 is not the answer,” the editorial said. “Surely there is a better way to manage the conflicts that arise when humans and their domestic animals move into areas that have long served as habitat for wildlife.”

P-45’s alien provenance aggravates the unease that Phillips and his neighbors feel. “I know P-45 is not indigenous to here,” Phillips told me. “I think he was a killer someplace else.” He added, “I’m not too happy about P-45’s genes getting passed down.” Though the young generally travel with their mothers — mountain-lion fathers are more likely to kill their kittens than to train them — he saw the potential for P-45 to accustom his offspring to a life of theft and slaughter. Besides, he said, “I’m tired of living inside a biology project.” If the California Department of Fish and Wildlife, which manages the state’s mountain-lion population, or the National Park Service, which he blames for protecting P-45, refused to solve the problem, he warned that vigilante justice would prevail.

“Somebody’s going to shoot him soon,” Phillips said. “They’re just not going to report it. They’re not going to call N.P.S., not going to call Fish and Wildlife. They’re just going to shoot him, pound the collar off with a hammer, put it in a lead box in a bucket of water, and bury P-45 ten feet deep. That will be the end of that story. He will pass from reality into legend.”

Puma concolor, an evolutionary adept that, unlike the sabre-toothed cat, survived the Late Pleistocene Extinction, is found from Tierra del Fuego to the Canadian Yukon. Until successive extermination campaigns largely eradicated mountain lions from the Midwest and the East, they ranged throughout the United States. Now, as urbanization in the West encroaches on their remaining habitat, some are making audacious attempts to reclaim ceded lands. In 2011, a cat from South Dakota travelled more than fifteen hundred miles, to Greenwich, Connecticut, before being struck and killed by an S.U.V. on the Wilbur Cross Parkway.

Los Angeles is one of two megacities in the world that have a population of big cats. In the other, Mumbai, leopards live in Sanjay Gandhi National Park and occasionally eat the humans who make their homes around its edge. Though there have been instances of mountain lions targeting people in California — between 1986 and 2014, there were three fatal attacks — it has never happened in Los Angeles County. (Since the beginning of the twentieth century, according to the Mountain Lion Foundation, there have been fewer than thirty fatal attacks in North America; it is an often cited fact that vending machines kill more people than mountain lions do.) “They’re called ghost cats for a reason — they’re very elusive,” Jeff Sikich, a carnivore biologist with the National Park Service, who manages the field work for the mountain-lion study, told me. “We’ve seen with our data that they do a great job at avoiding us.” But, he said, “in this urban, fragmented landscape, they see us almost every day.”

No, the wooly mammoth won’t be resurrected by 2019

Saturday, February 18th, 2017

No, the wooly mammoth won’t be resurrected by 2019:

“Our aim is to produce a hybrid elephant-mammoth embryo,” Harvard’s George Church told The Guardian. “Actually, it would be more like an elephant with a number of mammoth traits. We’re not there yet, but it could happen in a couple of years.”

The key word there is embryo. Church’s team — the Wooly Mammoth Revival project — is using CRISPR gene-editing technology to put genetic traits collected from frozen mammoth corpses into Asian elephant DNA.

So far, they’ve managed to incorporate traits of the mammoth’s ears, fat, and hair into elephant DNA. In a few years they hope to make an embryo, but that’s a long way from creating a viable embryo. A viable embryo would have to be able to survive long enough to move from a Petri dish to some kind of womb — and then it would have to grow into a healthy calf that the team could successfully deliver and raise.

Artificial gestation is considered the most likely option for any viable embryo, because Asian elephants, the closest living relatives of mammoths, are currently endangered. Church has created an artificial womb capable of gestating a mouse embryo for 10 days but that’s a far cry from the 660-day gestation period of an elephant calf.

So while an embryo may indeed be possible by 2019, there’s no telling how many years would stretch between that milestone and the actual reintroduction of the woolly mammoth. Researchers have already created embryos of chickens with dinosaur snouts, for example, and those dino-chickens aren’t clucking around a co-op. The first attempts to make a living mammoth are many more years away.

The Social Carrying Capacity for Hipsters and Bears

Saturday, January 28th, 2017

The mountain town of Asheville, North Carolina has attracted countless hipsters — and black bears:

New developments [in the 1990s] meant more room for people — but, as residents and scientists soon learned, they were also perfect safe spaces for bears, full of food and birdseed and free from hunters. As Asheville grew into a thriving metropolis, the bears stuck around and thrived, too, lumbering between the sprawling Smokey Mountains and the cramped yet trash-rich developments. In 1993, the Wildlife Resources Commission got 33 calls about human-bear encounters. In 2013, they got 569.

The scientists behind the Urban-Suburban Bear Study are looking at this influx from a number of angles, investigating the bear’s lifestyles, travel routes, and family relationships. But they’re also interested in figuring out this new habitat’s “social carrying capacity” — in other words, exactly how many of these new neighbors the human residents of the city are willing to tolerate. “If the habitat can support a lot, but the public doesn’t want them, we run into issues,” says Dr. Chris DePerno, the study’s principal investigator.

The very design of the study requires a certain amount of public support. Residents throughout the city have volunteered to host humane traps on their property. Scientists check the traps every morning and evening, or more often if a resident alerts them to activity. If a bear has wandered in, they come by, attach a GPS collar to track the bear’s movements, and then let it go. If they couldn’t use people’s backyards as bait, the whole study would be doomed. “Everything we do is on private land,” says DePerno. “If we didn’t have public support, we could not have done this project — but we’ve had a tremendous amount of support.”

Of course, the reverse is also true — involving the public in the study has allowed the researchers to teach ordinary civilians about bear management, answering their questions, assuaging their fears, and making sure that they do not, under any circumstances, feed them. This makes DePerno hopeful — if city people can accept bears, maybe there’s a chance that other animals driven into civilization will get a fair shake. “It goes beyond just bears in Asheville,” he says. “We’re hoping to educate other scientists and the public on the potential for managing other urban species.”

Having bears next door does require shouldering some unique responsibilities. In bear-heavy areas, Ashevillians are asked to put their trash out the morning of pickup rather than the night before. When that’s not enough, a kind of arms race can ensue, with some residents chaining their cans to trees and bolting the lids. (Boll freezes any food trash and puts her bag of used cat litter on top of it on trash day, and says it works like a charm.)

Birdfeeders are pretty much a no-go — bears will crush the whole feeder like it’s one big seed, and gobble up the contents. They like to claw the covers off of hot tubs. And in Boll’s neighborhood, walking at night requires a small gear kit: “You carry a light and a whistle, and you’re constantly on the lookout,” she says. “Not because anything that has happened that I know of — but because hello, there are bears!”

But most human residents seem to think it’s worth it. “Every single bear sighting I’ve had has impressed me a lot, because I’m in awe of them,” says Boll. She says she doesn’t know anyone anti-bear, and that new residents who are confused or frightened are quickly educated by their neighbors, if the scientists don’t get to them first. Researchers have extremely detailed bear whereabouts data, but they haven’t released it — not because they fear vengeance against the bears, but because they’ve realized that people love the bears too much, and might go looking for them.

Oxytocin levels surge in troops of chimpanzees preparing for conflict with rival groups

Thursday, January 19th, 2017

Oxytocin levels surge in troops of chimpanzees preparing for conflict with rival groups:

The finding is at odds with the prevailing image of oxytocin as something that helps strengthen bonds between parent and infant, or foster friendships. But given its capacity to strengthen loyalty, oxytocin could also be a warmonger hormone that helps chimps galvanise and cooperate against a common enemy.

Catherine Crockford of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and her colleagues monitored two rival groups of chimpanzees in the Taï National Park in Ivory Coast, each containing five males and five females, for prolonged periods between October 2013 and May 2015.

Thanks to trust built up between the team and the chimps, the team could safely track and video the groups – even during conflict, observing at close quarters what was happening. Crucially, the team was also able to pipette up fresh samples from soil when chimps urinated.

The samples revealed that oxytocin levels surge in the mammals whenever the chimps on either side prepared for confrontation, or when either group took the risk of venturing near or into rival-held territories. These surges dwarfed the oxytocin levels seen during activities such as grooming, collaborative hunting for monkey prey or food sharing.

Mammals Are Downright Drab

Sunday, December 4th, 2016

Compared to colorful fish, lizards, birds, and insects, we mammals are downright drab:

Unless you are a color scientist you are probably accustomed to dealing with chemical colors. For example, if you take a handful of blue pigment powder, mix it with water, paint it onto a chair, let it dry, then scrape it off the chair, and grind it back into powder, you expect it to remain blue at all stages in the process (except if you get a bit of chair mixed in with it.)

By contrast, if you scraped the scales off a blue morpho butterfly’s wings, you’d just end up with a pile of grey dust and a sad butterfly. By themselves, blue morpho scales are not “blue,” even under regular light. Rather, their scales are arranged so that light bounces between them, like light bouncing from molecule to molecule in the air.

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This kind of structural color works great if your medium is scales, feathers, carapaces, berries, or even CDs, but just doesn’t work with hair, which we mammals have.

Compared to other animals, mammals also have bad color perception, which may be explained by the nocturnal bottleneck hypothesis:

The hypothesis states that mammals were mainly or even exclusively nocturnal through most of their evolutionary story, starting with their origin 225 million years ago, and only ending with the demise of the dinosaurs 65 millions years ago. While some mammal groups have later evolved to fill diurnal niches, the 160 million years spent as nocturnal animals has left a lasting legacy on basal anatomy and physiology, and most mammals are still nocturnal.