November 12, 2013
In the summer of 2010, husband-and-wife paleobiologist team Z. Jack Tseng and Juan Liu traveled to the Zanda Basin in western Tibet with a group of colleagues. The remote area, a week’s drive from Beijing and near the border of Pakistan and China, is “basically badlands everywhere, with deeply cut valleys throughout,” Tseng says.
To explore the valleys, the team drove up dirt trail after dirt trail before coming upon a dense patch of fossils sticking out of the ground halfway up a hill. “In the little concentration of fossils, there were lots of limb bones from antelopes and horses obscuring everything else,” says Tseng, who was then a graduate student at USC and is now with the American Museum of Natural History. “It wasn’t until we started lifting things up, one by one, that we saw the top of a skull, and we thought, from the shape, that it looked something like a cat.”
After a few years of analysis, Tseng’s team has discovered that the skull doesn’t belong to any old cat. As they’ve documented in a study published today in Proceedings of the Royal Society B, the skull and six associated fossilized jawbone fragments are the first evidence of a newly discovered species, which they’ve called Panthera blytheae. The discovery represents the oldest “big cat” (a group that includes large predatory cats like lions, jaguars, tigers and leopards) ever found by a wide margin.
The sediments that make up the basin as a whole range from 6 million to 400,000 years in age, so the group dated the fossil by analyzing the age of the particular rock layers it was buried in. This involved using techniques of magnetostratigraphy, in which scientists analyze the magnetic orientation of the rocks and compare it to known reversals of the Earth’s magnetic field. This method can only provide rough estimates for an item’s age, but it revealed that the skull is between 4.10 and 5.95 million years old. Previously, the oldest known big cat fossils—a number of tooth fragments found in Tanzania—were 3.6 million years old.
The new find fills a gap in the evolutionary record of big cats. By analyzing the DNA of living species, scientists had previously estimated that big cats had split from the Felinae subfamily—which includes smaller wild cats, like cougars, lynxes, along with domestic cats—about 6.37 million years ago. The very existence of P. blytheae confirms that the split happened prior to when this big cat roamed.
But how much earlier? The find could suggest, Tsang says, that big cats branched off from smaller cats much farther back than thought. By comparing the skull’s characteristics with fossils from other extinct big cats, the anatomy of living cat species, and DNA samples taken from both living cats and a few recently extinct, Ice Age-era species (known as cave lions), the researchers assembled a new evolutionary family tree for all big cats. Using known rates of anatomical changes over time and the observed anatomy of P. blytheae, they projected backwards, and estimated that the earliest big cats likely branched off from the Felinae subfamily between 10 and 11 million years ago.
The new fossil also solves a geological mystery. Previously, using DNA analysis of all living big cats and mapping the the fossils excavated from various sites around the world, researchers had determined it was most likely that their common ancestor had lived in Asia. The oldest known specimens, however, were found in Africa. The new species provides the first direct evidence that central Asia was indeed the big cats’ ancestral home, at least as far back as the current fossil record currently goes.
From the fragmented fossils, it’s hard to know much about the extinct species’ behavior and lifestyle, but the researchers were able to make some basic extrapolations from the skull’s anatomy. “It’s not a huge cat, like a lion or a tiger, but closer to a leopard,” Tsang says. The creature’s habitat was likely similar to the current Tibetan plateau, so Tseng speculates that, like the snow leopards that currently live in the area, this species did not hunt on the open plains, but rather cliffs and valleys. Tooth wear patterns also suggest similarities with current snow leopards—the rear teeth, likely used for cutting soft tissue, remain sharp, whereas the front teeth are heavily worn, perhaps reflecting their use in prying open carcasses and picking meat off bones.
Tseng says that he and colleagues plan to return to the area to search for more fossils that could help enlighten us on the evolutionary history of big cats. “The gap still isn’t completely filled yet,” he says. “We need to find older big cats to put the picture together.”
June 11, 2013
Science is generally considered a rather serious business, full of big questions, dense calculations and incomprehensible jargon.
Then there is the Annals of Improbable Research, a venerable journal that has published data on the effects of peanut butter on the rotation of the Earth and how access to television can be an effective method of birth control. The publication’s stated goal is to publish “research that makes people laugh and then think.” Its articles—which are mostly satire, but with some occasional real research into offbeat issues—probably accomplish the former goal more often than the latter, but they do often contain a grain of scientific truth at their core. And, of course, the organization’s Luxuriant Flowing Hair Club for Scientists™ is an indispensable institution on the international scientific landscape.
For your reading pleasure, we bring you an (admittedly unscientific) list of the 5 most improbable research projects from the Annals:
How did Fiorella Gambale, a scientist at the (nonexistent) Institute for Feline Research in Milano, Italy, answer this age-old question? Simple: she dropped the cat Esther 100 times each from a variety of heights and charted the results. Improbably, the cat landed on its feet all 100 times when dropped from 2, 3, 4, 5 or 6 feet, but failed to do so even once when dropped from 1 foot.
Although these results were never vetted by other scientists—so there’s no way of knowing whether Gambale actually performed the tests—the finding that cats really do land on their feet when dropped from more than 12 inches from the ground actually does jibe with established scientific beliefs. The explanation is that they need a few seconds of free fall to trigger their righting reflex, which allows them to bend their back and twist their torso to orient their feet towards the ground.
“The field of culinary evolution faces one great dilemma,” wrote Joseph Staton, of Harvard’s Museum of Comparative Zoology. “Why do most cooked, exotic meats taste like cooked Gallus gallus, the domestic chicken?” Staton tasted a wide variety of meats (including kangaroo, rabbit, goose, pigeon, and iguana) in exploring the question, and ultimately determined that the quality of “chicken taste” is a conserved trait, something that came about once in the evolutionary history of invertebrates and was passed on to many species.
Sadly, Staton’s attempt to sample dinosaurs was thwarted: He apparently made several calls to Chicago’s Field museum to “borrow merely a single bone” from their T. rex but his request was “entangled in red tape.”
A team of geologists from Texas State and Arizona State Universities addressed this very serious question with the cutting-edge tools of their field: digital elevation analysis software, complex mathematical equations, and a standard-size flapjack from the local IHOP. They found that Kansas is, in fact, considerably flatter than an average pancake, which is actually more rugged than the Grand Canyon when viewed up close. They write that Kansas, on the other hand, “might be described, mathematically, as ‘damn flat.’”
Comparing these two fruits is not quite so difficult, it turns out, when you have access to a Nicolet 740 FTIR spectrometer, which can precisely measure the frequencies of light emitted from any substance. Scott Sandford, a NASA researcher, put this device to use on dried samples of a Granny Smith apply and Sunkist orange that had been pulverized and compressed into pellets. He found that the spectrums of light emissions from the fruits were remarkably similar, a rather stunning revelation given how frequently people employ the what he calls the “apples and oranges defense”: that we should avoid comparing two different things because of how different the fruits are.
“It would appear that the comparing apples and oranges defense should no longer be considered valid,” Sandford wrote. “It can be anticipated to have a dramatic effect on the strategies used in arguments and discussions in the future.”
Alice Shirrell Kaswell, a staff member at the Annals of Improbable Research, definitively answered this question once and for all in 2003: The chicken, it turns out, came approximately 11 hours before the egg. Kaswell came to this finding by separately mailing a dozen eggs and one (1) live chicken via the U.S. Postal Service from Cambridge, Massachusetts to New York City. Both items, sent out on a Monday, arrived on Wednesday, but the chicken was delivered at 10:31 a.m., while the eggs didn’t arrive until 9:37 p.m. Problem = solved.
January 29, 2013
There are so many ways for a little bird or squirrel to die these days–they can be squished by cars, splattered into buildings, run over by bulldozers, poisoned or even shot. But if you have ever had to clean up a mangled “present” left on your doorstep by a kitty, you’ll know that little creatures can also be killed by pets.
Cats in particular have earned a nasty reputation for themselves as blood thirsty killers of wildlife. They have been named among the top 100 worst invasive species (PDF) in the world. Cats have also earned credit for countless island extinctions. Arriving onto the virgin specks of land alongside sailors, the naive native fauna didn’t stand a chance against these clever, efficient killers. All said, cats claim 14 percent of modern bird, amphibian and mammal island extinctions. But what about the mainland?
A recent study aimed to find out just that. Now the stats are in, and it’s much worse than we thought. But before bird lovers rush to declaw pets, the study’s scientists also found that feral cats and strays–not house cats–are responsible for the majority of the killings.
To arrive at the new findings, researchers from the Smithsonian’s Migratory Bird Center and the U.S. Fish and Wildlife Center assembled a systematic review of every U.S.-based cat predation study known in the scientific literature (excluding Hawaii and Alaska). Based on figures the authors verified as scientifically rigorous, they statistically quantified the total bird and small mammal mortality estimate caused by cats, further breaking the categories down into domestic versus unowned cats, that latter of which the authors define as barnyard kitties, strays that receive food from kind humans and cats that are completely wild.
Their results paint a grim picture for wildlife. In a paper published today in Nature Communications, they write that between 1.4 to 3.7 billion birds lose their lives to cats each year in the United States. Around 33 percent of the birds killed are non-native species (read: unwelcome). Even more startlingly, between 6.9 to 20.7 billion small mammals succumb to the predators. In urban areas, most of the mammals were pesky rats and mice, though rabbit, squirrel, shrew and vole carcasses turned up in rural and suburban locations. Just under 70 percent of those deaths, the authors calculate, occur at the paws of unowned cats, a number about three times the amount domesticated kitties slay.
Cats may also be impacting reptile and amphibian populations, although calculating those figures remains difficult due to a lack of studies. Based upon data taken from Europe, Australia and New Zealand and extrapolated to fit the United States, the authors think that between 258 to 822 million reptiles and 95 to 299 million amphibians may die by cat each year nationwide, although additional research would be needed to verify those extrapolations.
These estimates, especially for birds, far exceed any previous figures for cat killings, they write, and also exceed all other direct sources of anthropogenic bird deaths, such as cars, buildings and communication towers.
The authors conclude:
The magnitude of wildlife mortality caused by cats that we report here far exceeds all prior estimates. Available evidence suggests that mortality from cat predation is likely to be substantial in all parts of the world where free-ranging cats occur.
Our estimates should alert policy makers and the general public about the large magnitude of wildlife mortality caused by free-ranging cats.
Although our results suggest that owned cats have relatively less impact than un-owned cats, owned cats still cause substantial wildlife mortality; simple solutions to reduce mortality caused by pets, such as limiting or preventing outdoor access, should be pursued.
The authors write that trap-neuter/spay-return programs–or those in which feral cats are caught, “fixed,” and released back into the wild unharmed–are undertaken throughout North American and are carried out largely without consideration towards to native animals and without widespread public knowledge. While cat lovers claim that these methods reduce wildlife mortality by humanely limiting the growth of feral colonies, the authors point out that the scientific literature does not support this assumption. Therefore, such colonies should be a “wildlife management priority,” they write. They don’t come out and say it but the implication is that feral cat colonies should be exterminated.
But feral cats, some animal rights advocates argue, are simply trying to eke out a living in a tough, unloving world. As the Humane Society explains, simply removing the cats may not be the most efficient means of solving the problem because cats that are inevitably left behind repopulate the colony, surrounding colonies may move in to replace the old and “the ongoing abandonment of unaltered pet cats…can also repopulate a vacated territory.” Feral cats, after all, are the “offspring of lost or abandoned pet cats or other feral cats who are not spayed or neutered.” Targeting irresponsible humans may provide a different solution, although spay/neuter laws are controversial.
In Washington D.C. alone, for example, there are more than 300 known feral cat colonies. Wildlife are victims of this problem, but feral cats are too as conditions for survival are tough. And as with so many other environmental banes, the root of the problem neatly traces back to a single source: humans. As the authors write in their paper, feral cats are the single greatest source of anthropogenic (human-driven) mortality for U.S. birds and mammals.
October 5, 2012
As autumn arrives, the approach of flu season is a real concern. Last year, thousands of people suffered from symptoms including a high fever, chills and fatigue—classic signs of the flu. Some 2,374 people in the United States were hospitalized for influenza during the last flu season—an incentive for many of us to get an annual flu vaccine, to avoid both getting sick and potentially passing on the flu to family members.
A group of veterinarians at Oregon State and Iowa State Universities is now looking into the risk of flu for an unexpected population that doesn’t have access to flu shots: dogs, cats and other household pets. “We worry a lot about zoonoses, the transmission of diseases from animals to people,” said Christiane Loehr, a professor at the OSU College of Veterinary Medicine. “But most people don’t realize that humans can also pass diseases to animals, and this raises questions and concerns about mutations, new viral forms and evolving diseases that may potentially be zoonotic. And, of course, there is concern about the health of the animals.”
We’re pretty well acquainted with zoonoses—diseases that can move from animals to humans—because of the high profile transmissions of the influenza strains H1N1 (“swine flu“) and H5N1 (“bird flu”) from animals in recent years. But, as it turns out, many diseases can also act as so-called reverse zoonoses, or anthroponoses, contagiously jumping from humans to other animals. This appears to be the case for H1N1: The researchers have discovered 13 cases in which H1N1 seems to have been passed from humans to pet cats, some of which ultimately died from the disease.
The first recorded instance, described in an article published by the team in Veterinary Pathology, took place in Oregon in 2009. While a cat owner was hospitalized with H1N1, both of her cats (which stayed indoors and had no contact with other sick people or animals) came down with flu-like symptoms and eventually died. A postmortem analysis of their lungs and nasal cavities turned up the H1N1 virus.
In the years since, the research team has turned up 11 more cats, one dog and even some ferrets that seem to have been infected with H1N1 due to human contact. The animals’ flu symptoms—respiratory disease and, for some, eventual death—resemble the same symptoms suffered by humans who encounter severe strains of the flu.
For the roughly 100 million U.S. households that have a cat or dog, this news might trigger immediate concern, and the researchers say that anyone experiencing flu-like symptoms should distance themselves from their pets in much the same way they would from other people. Since this area has been the subject of so little attention, they say that there might be many more undiscovered cases of the flu jumping from humans to pets. “It’s reasonable to assume there are many more cases of this than we know about, and we want to learn more,” Loehr said.
Realistically, though, the actual number of animals infected is quite small when compared to the population at large. The bigger worry is that the flu virus could mutate into a more dangerous form as it is transmitted from humans to animals. “Any time you have infection of a virus into a new species, it’s a concern, a black box of uncertainty,” Loehr noted.
The influenza virus in particular mutates notoriously easily, with entire segments of its genome changing within a generation. The reason that H1N1 was declared a “national emergency” in 2009 was because it was a strain that mutated when it jumped from pigs to humans, raising the possibility that it had taken on a more deadly form that could be transmitted more easily between people.
In a worst-case scenario, the pets we keep in our homes could serve as the same type of mutation-inducing vector—the flu could be passed from human to pet, mutate into a more dangerous form, and then potentially affect both humans and other animals. “In terms of hosts and mutations, who’s to say that the cat couldn’t be the new pig?” Loehr asked. “We don’t know for sure what the implications might be, but we do think this deserves more attention.”
July 13, 2012
Snow leopards live in the remote mountains of countries such as Bhutan, China, India, Mongolia and Nepal. They are endangered—a mere 4,000 to 6,000 individuals are spread out over Central Asia—and live solitary lives, usually active just at dawn and dusk. Coupled with their exceptional camouflage, this makes them notoriously elusive—although they figure largely in the mythology of many Asian cultures, wild snow leopards weren’t even caught on camera until the 1970s.
Now, for the first time, a team of researchers from the Snow Leopard Trust and Panthera, a wild cat conservation organization, have captured video of a wild snow leopard mother and cubs in a den, seen above. “This is incredible. Snow leopards are so rare and elusive that people often talk about them as ‘ghosts’ of the mountains,” said Brad Rutherford, Executive Director of the Snow Leopard Trust. “This is the first documented visit of a den site with cubs, and thanks to this video we can share it with the world.”
The search began back in 2008, when an team of scientists affixed GPS collars to several snow leopards encountered in Mongolia’s Gobi Desert. Then, this past May, a pair of females from the study began restricting their movements to a smaller area, indicating they were preparing to give birth. Researchers tracked the VHF signals emitted by the collars through steep mountain outcroppings, coming upon a pair of dens located less than four miles apart in the Tost Mountains on June 21st.
“As we stood outside the den we could hear the cub and smell the cats but not see anything inside the den,” said Panthera scientist Orjan Johansson. He and colleagues acted quickly, taping a camera to their antenna pole and extending it over the ledge blocking the den entrance. The footage captured shows a female leopard looking up at the camera, keeping a protective paw over her cub.
At the second den—a narrow crack in a cliff wall—the scientists discovered that the mother was away hunting, leaving her two male cubs unattended, seen below. “This was an unprecedented opportunity,” said Rutherford. “We wanted to be as careful as possible and only take the most pressing data.” The team quickly weighed, measured, photographed and collected hair samples from the cubs, which allowed genetic testing that confirmed sex and other information. More pictures of the cubs are available at Panthera’s photo gallery.
The team also implanted microchip ID tags—each of which are roughly the size of a grain of rice—under the cubs’ skin, which will allow the researchers to identify the animals as part of future conservation projects. After leaving, they tracked signals from the mother’s VHF collar to ensure that she returned to the den, and they note that she is still with the cubs now. The researchers do not plan to visit the dens again, so as to limit future disturbance to the cubs.
The team says that the information collected will be extremely valuable in future attempts to conserve the endangered species. Remarkably little is known about snow leopard behavior, and most of what we understand about the rearing of cubs is known from studying the animals in a zoo environment. Until know, scientists had to speculate about typical litter sizes, cub weights, sex ratios and survival rates.
“Knowledge about the first days and weeks of life is vital to our understanding of how big cat populations work, and how likely it is for a newborn to reach adulthood and contribute to a healthy population,” said Panthera’s Howard Quigley. “A valid conservation program requires such information, which this new development in snow leopard research provides.”
The organization plans to use the microchip ID tags affixed to the cubs to learn about the characteristics of a typical snow leopard upbringing, such as how long the cubs remain in dens, when they being to hunt with their mothers and when they start to venture out on their own. Along with future GPS collaring programs, these data will assist with large-scale conservation efforts across the species’ range.
“We have spent years trying to determine when and where snow leopards give birth, the size of their litters and the chances a cub has of surviving into adulthood,” said Tom McCarthy, director of Panthera’s snow leopard program. “This is one of those exceptional moments in conservation where after years of effort, we get a rare glimpse into the life of an animal that needs our help in surviving in today’s world.”