by Greg Miller Scientific inspiration sometimes comes from unlikely sources. Two years ago, Gregory Berns, a neuroeconomist at Emory University in Atlanta, was on the couch with his kids watching American Idol. One of the contestants sang the melancholy hit song Apologize by the alternative rock band OneRepublic, and something clicked in Berns's mind. He'd used the song a few years earlier in a study on the neural mechanisms of peer pressure, in this case, how teenagers' perceptions of a song's popularity influence how they rate the song themselves. At the time, OneRepublic had yet to sign its first record deal. A student in Bern's lab had pulled a clip of Apologize from the band's MySpace page to use in the study. When Berns heard the song on American Idol, he wondered whether anything in the brain scan data his team had collected could have predicted it would become a hit. At the time, all 120 songs used in the experiment were by artists who were unsigned and not widely known. "The next day, in the lab, we talked about it." To find out what had become of the songs, the lab bought a subscription to Nielsen SoundScan, a service that tracks music sales. The database contained sales data for 87 of the 120 songs (not surprisingly, many songs had languished in MySpace obscurity). Berns reexamined the functional magnetic resonance imaging scans his group had collected from 27 adolescents in 2007, looking for regions of the brain where neural activity during a 15-second clip of a song correlated with the subject's likeability ratings. Two regions stood out: the orbitofrontal cortex and the nucleus accumbens. "That was a good check that we were on the right track, because we knew from a ton of other studies that those regions are heavily linked to reward and anticipation," Berns says. © 2010 American Association for the Advancement of Science.

Keyword: Hearing; Brain imaging
Link ID: 15418 - Posted: 06.11.2011

by Sarah C.P. Williams Craving an afternoon snack? Take a drag on a cigarette, and your hunger will likely disappear. Smoking is the number one cause of preventable deaths in the Unites States and other developed countries, causing lung cancer, heart disease, and chronic bronchitis. But smokers are, on average, skinnier than nonsmokers. New research reveals how nicotine, the active ingredient in cigarettes, works in the brain to suppress smokers' appetites. The finding also pinpoints a new drug target for nicotine withdrawal—and weight loss. The nicotine receptor in the brain has 15 subunits; they can combine in a multitude of ways to form different receptors with different jobs. Nicotine can bind to each combination and spur a cascade of distinct events; some lead to the addictive properties of cigarettes, others to an increase in blood pressure or a feeling of relaxation. It's long been known that nicotine causes a slump in appetite, and scientists suspected that this worked through receptors associated with reward and behavior reinforcement. After all, the brain considers both cigarettes and food to be rewards. But the new finding suggests that appetite has its own pathway. Behavioral neuroscientist Marina Picciotto of Yale University set out to study whether activating one particular nicotine receptor, dubbed α3β4, had antidepressant effects on mice. But as postdoctoral researcher Yann Mineur was caring for the mice, which had received drugs engineered to stimulate only α3β4 receptors, he noticed a side effect: the mice were eating less. © 2010 American Association for the Advancement of Science. .

Keyword: Obesity; Drug Abuse
Link ID: 15417 - Posted: 06.11.2011

By Lauren F. Friedman Anthony Weiner, the once cheered, now shamed New York congressman, made at least two mistakes in the past two weeks. First, he lied, and then he cried. "I have exchanged messages and photos of an explicit nature with about six women over the last three years," he admitted, after denying three days earlier that he publicly posted an R-rated picture of himself via Twitter. He punctuated his June 6 confession with frequent sniffling. Cameras caught him wiping away a tear at least once, and The New York Times referred to him as "weeping and stammering". Tears can take on different meanings depending on who leaks them and when. Here's why Weiner's waters went awry. "Crying evolved as a signal to others that we're vulnerable and in need, but we have to consider whether or not the situation is one where it is appropriate to show one's vulnerability," says Randolph R. Cornelius, a professor of psychology at Vassar College who has studied crying for decades. "There are lots of situations where we don't want to do that." Weiner might have hoped that his crying—however genuine it may have been—would elicit sympathy, but research and history have shown that people do not universally respond kindly to tears. A seminal 1982 study on self-presentation suggested that whereas people tend to reveal their own weakness as a cry for help, an emotional display can easily backfire. Most research shows that a typical response to crying is to offer emotional support, but that doesn't mean that our reaction to tears is uniformly positive. © 2011 Scientific American,

Keyword: Emotions
Link ID: 15416 - Posted: 06.11.2011

FOR people worried about the feminising effect of oestrogen-like chemicals in the water there is now a modern-day equivalent of the canary in the coal mine: a genetically modified fish in a bowl. Male fish exposed to oestrogen have delayed sperm development and grow smaller testes. Some industrial chemicals, such as bisphenol A, mimic oestrogen, but little is known about how the effects of different oestrogen-like chemicals add up in water. To find out, Xueping Chen and colleagues at Vitargent, a biotechnology company in Hong Kong, have created a genetically engineered fish that glows green when it is exposed to oestrogen-like chemicals. Chen's team took the green fluorescent protein gene from jellyfish and spliced it into the genome of the medaka fish, Oryzias melastigma, next to a gene that detects oestrogen. Chemicals that have oestrogen-like activity cause the fish to express the modified gene, making them glow. When the team tested the fish at eight sites around Hong Kong, they found that some chemicals that showed weak or no oestrogenic activity, including UV filters used in sunscreen, had combined in water to amplify or create an oestrogenic effect. The work is as yet unpublished. William Price of the University of Wollongong in New South Wales, Australia, warns the approach does not detect a biological response. © Copyright Reed Business Information Ltd.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 15415 - Posted: 06.11.2011

Analysis by Marianne English Red can symbolize danger, heat and even anger. It's true: The color's appearance in road signs, stoplights, labels and flushed cheeks often cautions humans to avoid harm. One study even found that Olympic competitors donning red uniforms were more successful at winning events, suggesting the color intimidates the competition. And a recent set of experiments featured in the journal Psychological Science indicates humans' apprehension of red may have evolutionary roots, leading to greater consideration of the color's use in human sports and primate habitats. In the study, Dartmouth College researchers measured reactions from rhesus macaque monkeys when they were given the option to take food from human testers. The species was studied because these primates have similar visual capabilities as humans and use redness as an expressive form of communication -- just like people blush or redden when aroused or angry. Scientists set up several experiments allowing the monkeys to "steal" food from human testers, each of whom dressed in a different color T-shirt and baseball cap -- either red, green or blue. Researchers predicted the monkeys would avoid stealing from the tester wearing red, and they were right. Monkeys preferred testers wearing green or blue and avoided those dressed in red, regardless of the tester's sex. The team says the monkeys' submissive actions suggest our avoidance of red may have evolved in humans' last common ancestor with © 2011 Discovery Communications, LLC.

Keyword: Emotions; Vision
Link ID: 15414 - Posted: 06.11.2011

By Melissa Dahl If you're hearing voices in your head, you may want to cut back on the caffeine. A recent Australian study showed a link between heavy coffee consumption, stress -- and auditory hallucinations. Here's what happened: The volunteers listened to white noise played through a computer's headphones for three minutes. Every time they heard even a snippet of Bing Crosby's White Christmas, they were told to press a hand tally counter. (They weren't aware of the real point of the study -- they were told it was about auditory perception.) The song was never played. But the participants who said they were very stressed, and very caffeinated -- those who regularly drank five or more cups per day, at 200 milligrams of caffeine each -- were more likely to imagine they'd heard it. "We believe that high stress, in addition to taking high levels of caffeine, makes people yet more stressed and thus makes them more likely to 'overreact' to the environment -- i.e., to hear things that just aren’t there," explains Simon Crowe, the lead author of the study and a neuroscientist at Australia's La Trobe University, located in Bundoora, Victoria. The report was published in the April issue of the journal Personality and Individual Differences It's worth noting here that there are some limitations to the study: The levels of stress and caffeine consumption were both self-reported by the 92 volunteers who participated in the experiment. And what if, somehow, the caffeine-stressball combo made participants more eager to try to please the researchers -- yes, of course we heard the song! It's lovely, isn't it?! © 2011 msnbc.com

Keyword: Drug Abuse; Hearing
Link ID: 15413 - Posted: 06.11.2011

by Jon Ronson THERE'S a children's picture book in the US called Brandon and the Bipolar Bear. Brandon and his bear sometimes fly into unprovoked rages. Sometimes they're silly and overexcited. A nice doctor tells them they are ill, and gives them medicine that makes them feel much better. The thing is, if Brandon were a real child, he would have just been misdiagnosed with bipolar disorder. Also known as manic depression, this serious condition, involving dramatic mood swings, is increasingly being recorded in American children. And a vast number of them are being medicated for it. The problem is, this apparent epidemic isn't real. "Bipolar emerges from late adolescence," says Ian Goodyer, a professor in the department of psychiatry at the University of Cambridge who studies child and adolescent depression. "It is very, very unlikely indeed that you'll find it in children under 7 years." How did this strange, sweeping misdiagnosis come to pass? How did it all start? These were some of the questions I explored when researching The Psychopath Test, my new book about the odder corners of the "madness industry". Freudian slip The answer to the second question turned out to be strikingly simple. It was really all because of one man: Robert Spitzer. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Schizophrenia
Link ID: 15412 - Posted: 06.09.2011

by Ferris Jabr Talk about intelligent design: a new polymer-covered electrode has the potential to monitor and deliver drugs to out-of-sync brain cells. If trials in animals are successful, it could one day help people to control epilepsy. Neuroscientists implant microelectrode arrays in brains to eavesdrop on – and sometimes influence – the electrical activity of neurons. Why not chemically influence the brain alongside this electrical manipulation, thought Xinyan Tracy Cui at the University of Pittsburgh, Pennsylvania, and her colleagues. So the team coated microelectrodes with an electrically conductive polypyrrole film. Then they loaded pockets within the film with different drugs and neurotransmitters such as glutamate, GABA and dopamine, and attached the arrays to samples of rat brain tissue. Applying an electrical current to the polymer caused it to change shape and release its drug cargo, which then acted on surrounding cells. Cui is currently working on replicating this demonstration in living rodents. Hits the spot Polypyrrole-coated microelectrode arrays, like ordinary arrays, could not only monitor neurons for unusual electrical activity but also deliver electrical impulses to keep neurons firing at the right tempo, like the brain pacemakers sometimes used to treat epilepsy. With the polypyrrole coating, however, microelectrode arrays could release drugs when they detect unusual activity – such as the haphazard electrical firing that characterises a seizure. Because electrodes reach into specific regions of the brain, the drugs would affect only neighbouring neurons. © Copyright Reed Business Information Ltd.

Keyword: Epilepsy
Link ID: 15411 - Posted: 06.09.2011

By Jeremy Laurance, Health Editor Scientists developing treatments for the devastating brain disorder Creutzfeldt-Jakob Disease (CJD) have unexpectedly blocked the onset of Alzheimer's disease, the most common cause of dementia. Researchers said they were "thrilled" at the unexpected discovery that two antibodies – extensively studied in relation to CJD – may also have an affect on Alzheimer's disease. Almost 500,000 people a year in the UK and 20 million worldwide suffer from Alzheimer's. The finding, published in Nature Communications, represents a "significant step forward in the battle to develop drugs to treat Alzheimer's disease," they say. The lead came from an American study by researchers at Yale University in 2009, which showed prion proteins causing CJD also play a role in Alzheimer's disease. The finding triggered a race by scientists to discover whether antibodies being developed as a treatment for CJD might also work against Alzheimer's. Now a study on mice at the Medical Research Council Prion Unit at University College London has indicated the antibodies block the damaging effects of a toxic substance called "amyloid beta", a protein which accumulates and becomes attached to the nerve cells in the brain. Over time, through its interaction with prion proteins, amyloid stops the nerve cells from communicating, causing memory loss, the distinctive symptom of Alzheimer's. ©independent.co.uk

Keyword: Alzheimers; Prions
Link ID: 15410 - Posted: 06.09.2011

A woman's cat ears perk up as she passes a young man in a park, only to flatten as she brushes off the encounter. A team of Japanese inventors have come with a new device that blends the country's fascination with cuteness and its penchant for experimental high-tech -- brainwave-controlled cat ears. The fluffy headwear reads users' brain activity, meaning the ears perk up when they concentrate and then flop down again to lay flat against the head when users enter a relaxed state of mind, say its developers. The gizmo is called "Necomimi" -- a play on the Japanese words for cat and ear, but the first two syllables are also short for "neuro communication", says Neurowear, the inventor team whose brainchild it is. "We were exploring new ways of communicating and we thought it would be interesting to use brainwaves," said Neurowear's Kana Nakano. "Because the sensors must be attached to the head, we tried to come up with something cute and catchy." A promotional video shows a young woman's cat ears perk up as she bites into a doughnut and again when she passes a young man in a park, only to flatten as she apparently brushes off the missed encounter, relaxes and smiles. robotic hand © 2011 Discovery Communications, LLC.

Keyword: Robotics
Link ID: 15409 - Posted: 06.09.2011

By Karen Weintraub, Globe Correspondent Could household chemicals be causing an increase in autism? The evidence isn’t cut and dried, but a coalition of environmental and health advocates said yesterday that it’s suggestive enough for people to worry. Shoppers can’t possibly avoid all potentially dangerous chemicals on their own -- questions have been raised about chemicals found in canned foods, clothing, furniture, cleaning products, pesticides, air pollution, cosmetics, toys and baby items. So, the government must do more to regulate them, the Safer Chemicals, Healthy Families group said. “We need chemical policy that protects our most vulnerable citizens,” said Donna Ferullo, director of program research at the Autism Society, a parent advocacy group. The Safer Chemicals, Healthy Families coalition called for an overhaul of the three-decades-old federal law that regulates chemical safety, called the Toxic Substances Control Act. Earlier this year, Senator Frank Lautenberg, D-NJ, introduced legislation to modify the law, though the odds of passing major chemical industry reform in an election year are slim. Chemical industry consultant Neal Langerman said he agrees that it’s time to overhaul the 1976 law -- not because of autism concerns, but because it doesn’t reflect current realities. The law was written, he said, at a time when scientists thought low-level exposure to most chemicals was safe. Now, Langerman said, we realize “we are more sensitive to these low levels than we thought we were.” And we’re also less willing today to believe companies and government when they say -- but don’t prove -- that products are safe. “That’s a significant change in our society,” said Langerman, also an officer with the American Chemical Society, a professional group for chemists. © 2011 NY Times Co.

Keyword: Autism; Neurotoxins
Link ID: 15408 - Posted: 06.09.2011

By Laura Sanders A plethora of genetic changes contributes to autism spectrum disorders, three new studies find. The new genetic data illustrate why researchers have struggled to find a single cause for the baffling suite of developmental and behavioral conditions, and may help point the way to a unifying process underlying them. The studies also begin to explain why autism spectrum disorders are more common in boys than girls. Though the specific genetic changes identified by a trio of papers in the June 9 Neuron account for only 5 to 8 percent of autism cases, what they reveal about the biology of autism may have much wider implications. “I think we’re still scratching the surface,” says Steve Scherer of the Hospital for Sick Children in Toronto, who wasn’t involved in the studies. “But we’re getting there, and I think these are very important papers.” Two of the studies examined DNA samples taken from carefully screened families, a cohort called the Simons Simplex Collection. Each family included two unaffected parents and one high-functioning child diagnosed with autism spectrum disorder. For most families, an unaffected sibling was also included. By studying genetic changes in unaffected family members, the researchers could find abnormalities — specifically, duplications and deletions of DNA called copy number variations — that were not passed down from parents but arose spontaneously in the genomes of affected children. “What was surprising is how unique each of the variants is,” says geneticist Huda Zoghbi of Baylor College of Medicine in Houston. “This really speaks to the immense heterogeneity of autism. We suspected it, but these data show it clearly.” © Society for Science & the Public 2000 - 2011

Keyword: Autism; Genes & Behavior
Link ID: 15407 - Posted: 06.09.2011

By BENEDICT CAREY Like any other high school junior, Wynn Haimer has a few holes in his academic game. Graphs and equations, for instance: He gets the idea, fine — one is a linear representation of the other — but making those conversions is often a headache. Or at least it was. For about a month now, Wynn, 17, has been practicing at home using an unusual online program that prompts him to match graphs to equations, dozens upon dozens of them, and fast, often before he has time to work out the correct answer. An equation appears on the screen, and below it three graphs (or vice versa, a graph with three equations). He clicks on one and the screen flashes to tell him whether he’s right or wrong and jumps to the next problem. “I’m much better at it,” he said, in a phone interview from his school, New Roads in Santa Monica, Calif. “In the beginning it was difficult, having to work so quickly; but you sort of get used to it, and in the end it’s more intuitive. It becomes more effortless.” For years school curriculums have emphasized top-down instruction, especially for topics like math and science. Learn the rules first — the theorems, the order of operations, Newton’s laws — then make a run at the problem list at the end of the chapter. Yet recent research has found that true experts have something at least as valuable as a mastery of the rules: gut instinct, an instantaneous grasp of the type of problem they’re up against. Like the ballplayer who can “read” pitches early, or the chess master who “sees” the best move, they’ve developed a great eye. © 2011 The New York Times Company

Keyword: Learning & Memory; Intelligence
Link ID: 15406 - Posted: 06.07.2011

By EMMA G. FITZSIMMONS CHICAGO — Martin Mireles says his mother was not happy with his tongue piercing: It didn’t fit his image as a former church youth leader. But as Mr. Mireles told her, it was for research. Paralyzed from a spinal cord injury since he was shot in the neck almost two decades ago, he was recently fitted with a magnetic stud that allows him to steer his wheelchair with his tongue. Now he is helping researchers at the Northwestern University School of Medicine here in a clinical trial of the technology, being financed with almost $1 million in federal stimulus funds. Mr. Mireles, 37, tested the equipment one recent afternoon by guiding a wheelchair through an obstacle course lined with trash cans. Mouth closed, he shifted the magnet to travel forward and backward, left and right. The study was one of about 200 projects selected from more than 20,000 applicants. “There was a ‘wow’ factor here,” said Naomi Kleitman, a program director at the National Institutes of Health and an expert on spinal cord injury research. “This is kind of a cool idea. The question is: Will it work well enough not to just be cool, but to be practical too?” A quarter-million Americans have severe spinal cord injuries, and experts estimate that there are about 10,000 new injuries each year. Millions more have some form of paralysis from an array of conditions, including stroke, multiple sclerosis and cerebral palsy. © 2011 The New York Times Company

Keyword: Robotics
Link ID: 15405 - Posted: 06.07.2011

By Jennifer Viegas The stress and high contact environment of horse shows may cause herpes to become active and contadious among horses, experts say. Equine herpes, a highly contagious infection among horses that can be fatal, may spread when stressed out show horses come together for competitions, according to animal health experts. That appears to have helped fuel the current equine herpes outbreak, which has killed at least 12 horses and sickened 72 others in 10 states so far. These states include Arizona, California, Colorado, Idaho, New Mexico, Nevada, Oklahoma, Oregon, Utah and Washington. "Most adult horses are infected with the virus," Philip Johnson, a professor of equine internal medicine at the University of Missouri's College of Veterinary Medicine, told Discovery News. "Like most herpes viruses -- human and animal -- infection leads to a life-long association between the virus and the host. In most healthy horses most of the time, the host's immune system prevents the virus from going active and being especially contagious." Given "the right circumstances," however, he said "the virus can defeat the constraints of the host's immune system and go active." © 2011 Discovery Communications, LLC.

Keyword: Stress; Neuroimmunology
Link ID: 15404 - Posted: 06.07.2011

About every 40 seconds, someone in the United States suffers a stroke, and more than 77 percent are first events. Although deaths due to strokes have declined, a stroke — caused by the sudden loss of blood flow to the brain or by bleeding in or around the brain, either of which can cause brain cells to die — can still have a staggering impact upon lives. New guidelines from the American Heart Association and the American Stroke Association offer updated advice for preventing a first stroke. Lower your blood pressure High blood pressure damages arteries so they clog or burst more easily, escalating the risks of both types of stroke: ischemic, caused by blockage of a blood vessel that supplies part of the brain; and hemorrhagic, the less common but deadlier stroke that occurs when a blood vessel bursts inside the brain. Treatment to lower blood pressure, including lifestyle changes and medication, can reduce those risks by a third. l  Recommendations: Have your blood pressure checked at least once every two years, more often if you’re 50 or older. If your reading is high-normal — above 120/80 mmHg but below 140/90, the cutoff for hypertension — try to lower it by adopting the lifestyle measures listed below. If your reading is 140/90 or higher, talk with your doctor about adding an antihypertensive drug. Improve cholesterol levels LDL (bad) cholesterol, a fatty substance in the blood, builds up plaque on artery walls, causing arteries to narrow. If plaque ruptures, a blood clot can form and block a blood vessel to the brain, causing a stroke.

Keyword: Stroke
Link ID: 15403 - Posted: 06.07.2011

by Kai Kupferschmidt The source of a deadly outbreak of Escherichia coli bacteria in Germany remains elusive as German officials today announced that the first tests of samples from a sprouts farm implicated in the outbreak were negative. The German farm had been shut down yesterday by authorities and the region's health minister had advised people not to eat the vegetables. The confusing turn of events comes less than a week after German officials suggested Spanish cucumbers were the source, only to later backtrack. Researchers are now analyzing the genome of the bacterium to understand its evolutionary history and possibly identify its source. Closer analysis of the genome might also offer some clues to how the Shiga toxin made by the bacterium is attacking the brain. This toxin normally targets the kidney, triggering the often fatal development of hemolytic-uremic syndrome (HUS). Usually neurological symptoms are seen in only a few percent of HUS cases, but in the current outbreak "about half the patients with HUS are developing neurological symptoms," Christian Gerloff, head of the neurology department at the University Medical Center Hamburg-Eppendorf, told ScienceInsider today. Alarm bells started going off when some patients showed problems finding words or giving the date, Gerloff recalls. It quickly became clear that a lot of patients were developing problems reading or doing simple calculations. "Patients were mixing up words and were disoriented. Later they developed muscle twitching and then progressing to epileptic fits," Gerloff says. © 2010 American Association for the Advancement of Science.

Keyword: Language; Epilepsy
Link ID: 15402 - Posted: 06.07.2011

We spend a third of our lives asleep. Every organism on Earth—from rats to dolphins to fruit flies to microorganisms—relies on sleep for its survival, yet science is still wrestling with a fundamental question: Why does sleep exist? During Shakespeare and Cervantes’ time, sleep was likened to death, with body and mind falling into a deep stillness before resurrecting each new day. In reality, sleep is a flurry of action. Trillions of neurons light up. The endocrine system kicks into overdrive. The bloodstream is flooded with a potent cocktail of critically vital hormones. Such vibrant activity begs the question: Where do we go when we go to sleep? Based on new sleep research, there are tantalizing signposts. Join us in exploring this slumbering journey. We’ll delve into the one-eyed, half-brained sleep of some animals; eavesdrop on dreams to understand their cognitive significance; and investigate extreme and bizarre sleeping behaviors like “sleep sex” and “sleep violence.” Join us in a discussion with leading researchers who delve into the one-eyed, half-brained sleep of some animals, eavesdrop on dreams to understand their cognitive significance, and investigate extreme and bizarre sleeping behaviors such as "sleep sex" and "sleep violence." Moderator: Carl Zimmer Participants: Carlos H. Schenck Marthew Wilson Niels Rattenborg © 2011 Scientific American,

Keyword: Sleep
Link ID: 15401 - Posted: 06.07.2011

Rowan Hooper, news editor IF YOU like to think of chimps as wise, rational tool-users, gorillas as gentle giants, or bonobos as sexed-up hippie apes, be prepared for a shock. Among African Apes, a collection of field diaries, is primatology given the Tarantino treatment. In the introduction, Martha Robbins of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, emphasises that extreme violence among primates is rare. The incidents described in the book stuck in the biologists' minds because they illustrate how aggression can influence ape society. They stuck in my mind too because, infrequent as they are, these are clearly not random episodes, but key moments in the lives of characters who behave in such familiar ways that we see ourselves in them. In the course of the book we learn about infanticide and violent infighting among silverback gorillas. We get to know Mlima, a gorilla the biologists have been observing almost daily for six years. Through diary entries we are there when they find her dying from wounds inflicted by a younger member of her own species. We also meet Volker, an ambitious young bonobo the researchers have followed for most of his life. Volker has close relations with Amy, a female whose baby the researchers believe he fathered, but the attention he pays her is finally punished: he is savagely beaten by his former friends. The biologists observe Volker's screaming face as he clings to a tree trunk, then never see him again. Josephine Head, also of the Max Planck Institute, describes how she tracked a trail of blood from where chimps had been vocalising loudly the night before, and made a horrible discovery: the spread-eagled body of an adult male chimp, his face battered and bruised, throat torn open and intestines dragged out. © Copyright Reed Business Information Ltd.

Keyword: Aggression; Evolution
Link ID: 15400 - Posted: 06.07.2011

by Shaoni Bhattacharya SEEMINGLY random acts of violence by bottlenose dolphins on porpoises could be down to sexual frustration among young males. Cases of the cetaceans killing other creatures for no apparent reason have been reported in UK waters. Now bottlenose dolphins have been seen attacking harbour porpoises in the Pacific Ocean. Crucially, these observations show for the first time that the attackers are young males (Marine Mammal Science, DOI: 10.1111/j.1748-7692.2011.00474.x). Mark Cotter at Okeanis, a non-profit conservation organisation in Moss Landing, California, and colleagues observed three acts of aggression by dolphins on lone porpoises. The dolphins chased the porpoises at high speed, rammed and then drowned them. In one particularly violent attack, three dolphins corralled their victim before seven others joined them to ram the porpoise to death. Cotter found most shocking the fact that two dolphins remained behind to play with the carcass before pushing it towards his boat. "It was almost like they said: 'We're done playing with it, here you go'." Competition for food does not seem to explain the attacks, as the dietary overlap between the two species is small, says Cotter. But the fact that 21 of the 23 attackers were males may be revealing. He believes that the attacks are "object oriented play" during the breeding season by young males who cannot get access to females because of competition from older males. "They are taking out their frustrations," he says. © Copyright Reed Business Information Ltd.

Keyword: Aggression; Sexual Behavior
Link ID: 15399 - Posted: 06.04.2011