Category: Animal research
The Secret Life of Urban Crows
From the old shopping bag she unsheathed the dead crow and turned it in what little sunshine strained through the fibrous clouds. The black feathers sparkled in the light, and close inspection revealed iridescent blues and purples. She covered it back up with a tan cloth and, with the draped bird lying breast down on her two upturned palms, stepped gingerly onto a patch of grass. She tore the linen away and unveiled the corpse to the gray heavens.
There was nothing at first, just an empty sky. Then, a caw. A crow appeared on a nearby power line. Then another caw and another crow. Suddenly crows flew in from all directions. Their plaintive entreaties soon combined into a chorus. New arrivals joined what quickly grew into a cacophonous dervish of black silhouettes swirling directly above Swift.
It was like sorcery. Conjuring dozens of birds from thin air by simply removing fabric from a body.
This, according to Swift, is what its like to attend a crow funeral—an instinctive ritual that evolved generations ago and was just discovered by humans; Swift coauthored an article on her findings in the journal Animal Behaviour in 2015. The gist: Upon spotting one of its dead, the flock attends to the fallen bird en masse with loud shrieking. Given enough time the throng will mob any predator it thinks is responsible, like say, a human in a Dick Cheney mask, or in a mask like the one Swift had in her bag (the lab affectionately refers to that be-soul-patched fellow as Joe).
Dogs have ‘episodic memories’ just like humans, suggests study
A team from Hungary have discovered that dogs are able to recall their owner’s actions, even when they were not specifically instructed to do so, suggesting that dogs, like humans, have what is known as “episodic memory” – memories linked to specific times and places.
“I think that dog owners more or less suspect, at least, that dogs can remember events from the past – what is novel is the type of memory they can use for doing so,” said Claudia Fugazza lead author of the study from the MTA-ELTE Comparative Ethology Research Group. “This study shows that they can use a type of memory that allows them to recall and remember events that were not known to be important.”
New videos prove crows can make complex tools that only humans have made before
Though we’ve long known that crows use tools to get food (and occasionally to amuse themselves), scientists have lacked definitive evidence. Which is why two intrepid researchers invented the crow tailcam, to record the inventiveness of these birds in the wild.
UK researchers Jolyon Troscianko and Christian Metz had observed crows making tools in the wild, as had some of their colleagues. But none of them ever caught this amazing feat of intelligence on video. A couple of years ago, Metz co-authored a paper about how crows make hooked tools, carefully fashioning them out of branches, in order to get at hard-to-reach grubs inside a piece of wood. But he was quick to point out that those feats of tool-making were done in captivity—where animals often develop a penchant for tool-making that they wouldn’t have in the wild. In a paper out last week from Biology Letters, however, Troscianko and Metz describe how they finally caught wild crows making their hooked tools on video.
Not to put too fine a point on it, they put cameras on the crows’ butts. More precisely, they used biodegradable rubber to attach tiny cameras to the birds’ two strongest tail feathers, giving the researchers a below-the-belly view of the crow’s activities. Because crows often lower their heads to foot level to eat and make tools, this was also an excellent vantage point to capture tool-making in action.
Apocalypse Pig: The Last Antibiotic Begins to Fail
On Thursday, researchers from several Chinese, British and US universities announced in the journal Lancet Infectious Diseases that they have identified a new form of resistance, to the very last-ditch drug colistin—and that it is present in both meat animals and people, probably comes from agricultural use of that drug, can move easily among bacteria, and may already be spreading across borders.
Dogs are man’s best friend thanks to bonding hormone, research shows
A rush of hormone that helps people bond could explain why humans and dogs have been best friends for thousands of years, say researchers in Japan.
The scientists found that dog owners experienced a surge of oxytocin when their pets gazed into their eyes, a dramatic effect that was mirrored in the animals themselves.
The same hormone has been shown to spike in mothers’ brains when they look into their children’s eyes. The physiological response drives maternal caring and strengthens the bond between mothers and their babies.
The latest finding suggests that dogs have tapped into this ancient biological mechanism, and through it reinforced the ties that have existed between humans and dogs since the animals were first domesticated thousands of years ago.
Dogs Know What That Smile on Your Face Means
Researchers don’t yet know whether the dogs’ ability to discriminate between the two expressions is because of past experiences or the result of the domestication process.
Whatever the reason, it’s not so surprising that dogs can tell facial expressions apart, Müller says. “Because they spend so much time with humans, they have a lot of opportunities to see human expressions.”
Marc Bekoff, a behavioral ecologist who specializes in canines at the University of Colorado, Boulder, agrees. People and dogs have forged an incredibly close connection over thousands of years together, says Bekoff, who wasn’t involved in the study. Along the way, dogs have been bred for certain traits, and “one of the traits would be the ability to read us.” (Read “How to Build a Dog” in National Geographic magazine.)
The question now is whether dogs that spend a lot of time with people would be as good at picking up our expressions as dogs without a lot of people experience, Bekoff adds.
How Dogs Understand What We Say
Psychologists reported Wednesday in the journal Current Biology that dogs do pay attention to the meaning of words. And they process that information in a different part of the brain than where they process emotional cues in speech.
To figure all that out, graduate student Victoria Ratcliffe at the University of Sussex in England set up a clever experiment. She brought 250 dogs into the lab. And then for each one, Ratcliffe put a speaker on either side of the dog’s head. Then she played the command “to come” out of both speakers, at the same time. At first, the command sounded normal. It had both meaningful words and emotional cues in it. Then Ratcliffe started to manipulate the speech in the command. In some instances, she removed all the inflections in the speaker’s voice. In other instances, she kept the inflections in the speaker’s voice but removed the words (or replaced the words with gibberish). For each command, Ratcliffe recorded which way the dogs turned their heads — toward the left speaker or toward the right speaker. Even though both speakers were playing the same sounds, a clear pattern emerged.
When the dogs heard commands that still had meaningful words in them, about 80 percent of the animals turned to the right. When they heard commands, with just emotional cues in them, most dogs turned to the left. That result sounds simple. But Andics, who wasn’t involved in the study, says the findings show something surprising: “That dogs are able to differentiate between meaningful and meaningless sound sequences.”
Cows Would Probably Prefer Less Cowbell, Study Finds
The iconic clanking of bells worn by bovine has been a part of idyllic countryside soundscapes for centuries, helping herdsman keep better track of their cattle grazing in the fields — but as it turns out, unlike Christopher Walken’s character in that famous Saturday Night Live sketch, cows would probably prefer a bit less cowbell.
According to a new study out of Switzerland, researchers from Federal Institute of Technology in Zurich found that the sounds produced by those heavy, metal bells wasn’t so pleasing to the animals who are forced to wear them. The team found that the ringing heard by cows laden with cowbells reached as high as 113 decibels, about as loud as a jackhammer.
“If someone had an eight-hour work day in 100-decibel noise, it is bad for his health,” says acoustics expert, Beat Hohman, to newspaper Schweiz am Sonntag. “In humans we would expect a hearing impairment to develop after being exposed to this high noise for a certain length of time.”
Researchers note that cattle’s hearing is much more sensitive than humans, making the deafening sound of metal on metal exactly that; they suspect that thousands of cows have lost their hearing because it.
How Animal Welfare Leads to Better Meat: A Lesson From Spain
It wasn’t until later, as we watched the pigs inhale their meal, that Armando talked about the rationale behind his methods. He explained that research being conducted in Australia and New Zealand is showing that when stress is minimized in animals, the meat has a lower pH and is consistently more delicate than in animals that experience stress during transport, handling, and slaughter. In other words, when it comes to making a high-quality, rarefied product like jamon Ibérico, a little tenderness goes a long way.
After the tour was done, Loli brought plates of fresh goat cheese and toast rounds spread with homemade pate to a picnic table beside the house, along with a warm salad of cilantro, red potatoes, carrots, tomatoes, and hard-boiled eggs, all from the garden and henhouse. I wondered out loud whether these studies might provide an economic incentive for animal welfare on factory farms. I later realized that industrial meat producers are already well aware that stress has adverse affects on meat. There are even names for the consequences of abuse, like Pale Soft Exudative (PSE). It’s so common in fact that the U.N. Food and Agriculture Organization talks extensively about PSE in its “Guidelines for Humane Handling, Transport and Slaughter of Livestock.” When the animals are subjected to manhandling, fighting in the pens, and bad stunning techniques, the fright and stress causes a rapid breakdown of muscle glycogen. This lightens the color of the meat and turns it acidic and tasteless, making it difficult to sell, so it is usually discarded.
According to research by Kansas State University, PSE causes the U.S. pork industry losses of $275 million annually. If not motivated by morals, industrial pig farmers could avoid profit loss by allowing animals to rest before they are slaughtered, giving them enough space and some water. Unfortunately, most meat today is ground beyond recognition and consumers can’t taste the difference, so the cost of creating stress-free environments for animals doesn’t pay off.
But there’s a side to this that’s more alarming than the threat of tasteless meat.The Journal of Animal Science and researchers at the University of Milan’s Faculty of Veterinary Medicine recently confirmed that fear experienced during slaughter significantly elevates meat’s levels of stress hormones—adrenaline, cortisol, and other steroids. Studies on human consumption of artificial growth hormones, which are believed by many to affect our reproductive systems and other bodily processes, have already resulted in policy changes in many countries, including those that make up the E.U. Attention is now turning to these naturally occurring fear-induced hormones as scientists worry that their consumption causes similar problems.
Clever Trout Match Chimps in a Cognitive Challenge
Certain forms of collaboration are supposed to be so sophisticated that only the smartest creatures—namely humans and perhaps a few close relatives—are capable of them. Yet this exclusive club has a new and unexpected member: a species of fish, a class of animals seldom associated with high-level intelligence.
As demonstrated in a series of experiments published today in Current Biology, coral trout not only solicit the help of moray eels when they hunt, but also pick their hunting partners wisely. They know when they need help, and quickly learn which eels best provide it. It’s a seemingly simple yet surprisingly sophisticated cognitive trick.
“Prior to our study, chimpanzees and humans were the only species known to possess both of these abilities,” said zoologist Alex Vail of England’s University of Cambridge. “I think the evidence is mounting that fish have more going on in their heads in terms of cognition than they have been given credit for.”
In earlier research, Vail and colleagues observed that coral groupers and coral trout—two closely-related species of large, reef-dwelling predatory fish found in the Indian and western Pacific oceans—used their bodies to point moray eels at prey hiding in otherwise inaccessible seabed holes. The eels followed directions, flushing prey from the holes and giving groupers an easy meal.
In the cognitive argot, this appeared to be evidence of referential communication: groupers didn’t merely express an emotional state or some straightforward want, as with a mating display. Rather, their gestures referred to an external object, and seemed to display conscious intent. It was not the behavior of a stimulus-response machine.
It was an exciting finding. In recent years, even as scientific journals burst with studies of clever crows and empathic rats and tool-using dolphins, fish remained at the back of the class. Yet that may say more about our own assumptions than anything else. Fish have been around for more than 500 million years, and have as much evolutionary incentive as other creatures to smarten up.
In the new study, Vail and his colleagues, fellow Cambridge zoologist Andrea Manica and biologist Redouan Bshary of Switzerland’s University of Neuchatel, decided to give coral trout an especially challenging test, adapting an experiment originally conducted with chimpanzees.
That experiment, published to widespread scientific acclaim in 2006, involved one chimp freeing another from a cage in order to jointly tug on a rope, thus releasing food that couldn’t be reached by a single chimp’s efforts. Chimps figured out when they needed help and learned which other chimps best provided it—aptitudes that until then had been considered uniquely human.