EAST LANSING, Mich.—When it comes to producing more offspring, larger female hyenas outdo their smaller counterparts. A new study by Michigan State University researchers, which appears in Proceedings of the Royal Society, revealed this as well as defined a new way to measure spotted hyenas’ size. “This is the first study of its kind that provides an estimate of lifetime selection on a large carnivore,” said MSU graduate student Eli Swanson, who published the paper with MSU faculty members Ian Dworkin and Kay Holekamp, all members of the BEACON Center for the Study of Evolution in Action. “In short, we were able to document that larger female hyenas have more cubs over their lifetime than do smaller females as well as develop a novel approach for estimating body size.” Size can be one of the most important traits affecting an animal’s life. It influences eating, getting eaten, speed and agility, and attractiveness to potential mates. However, overall height and weight measurements may not capture differences in more specific traits like leg length that might be more important in survival. To identify the most-important traits, researchers sedated hyenas in Kenya and took 13 measurements on each subject, including total body length, skull size and leg length. They found that while overall size didn’t affect reproductive success, some clusters of traits did. They also learned that the length of the lower leg, the height at the shoulder and body length were all individually associated with more reproductive success. © 2011 U.S.News & World Report LP

Keyword: Evolution; Sexual Behavior
Link ID: 15149 - Posted: 03.29.2011

A drug containing the sleep hormone melatonin is to be tested in Scotland to find out if it helps reduce the effects of dementia. Glasgow-based firm, CPS Research, aims to recruit 50 people with Alzheimer's disease for the clinical trial of the drug, Circadin. Alzheimer's patients do not have normal melatonin levels and the study will gauge the effects of adding it. Initial findings suggest it may lead to improved well being during the day. The most common cause of dementia is Alzheimer's disease - which causes the death of brain cells - but other conditions that affect the brain can also cause it. Dr Gordon Crawford, of CPS Research, said: "Dementia is a shattering condition for patients, their families and friends. By reducing the symptoms of the illness, it is hoped that both patients and their carers can enjoy a better quality of life and manage the condition more effectively. "In our groundwork for this project we investigated a slow-release version of the natural compound melatonin. Our findings suggested that the participants functioned better during the day - possibly due to a better quality sleep pattern." BBC © MMXI

Keyword: Alzheimers; Biological Rhythms
Link ID: 15148 - Posted: 03.29.2011

by Andy Coghlan The molecules that fuel thinking and memory have evolved far more in human brains compared with other primates. Philipp Khaitovich of the Partner Institute for Computational Biology in Shanghai, China, and colleagues analysed brain tissue from deceased humans, chimpanzees and rhesus macaques to study the concentrations of 100 chemicals linked with metabolism. In the human prefrontal cortex, the levels of 24 of these were drastically different from levels in the corresponding brain regions of the other primates. In the cerebellum, however, there were far fewer differences between humans and the other animals, with just six chemicals showing different concentrations. This suggests that, since our lineage split off from other primates, the evolution of metabolism in the thinking and learning parts of our brains has gone much further than in our "primitive" cerebellum. Khaitovich says the comparison confirms the key role played in human thought by glutamate, a chemical that energises brain cells and ferries messages between them. It was present at relatively low levels in humans, which he says is because it is used faster in energy-hungry human brains. "Brain metabolism probably played an important role in evolution of human cognition," Khaitovich says, "and one of the potentially most important changes was in glutamate metabolism." © Copyright Reed Business Information Ltd.

Keyword: Evolution; Attention
Link ID: 15147 - Posted: 03.29.2011

By Carolyn Y. Johnson In a small, plain room at the Boston Children’s Museum, scientists are asking deep questions about the foundations of human knowledge — with the help of toddlers and squeaky balls. At the Museum of Science, they are watching children play, gaining insights into how teaching works. Among the lessons: Teaching too much can stifle exploration. Until recently, mystery surrounded the precise ways in which babies and toddlers begin to make sense of the world. But researchers, with clever experiments at these museums and elsewhere, are finding that young children have a surprisingly sophisticated intuitive grasp of probabilities, which they use to make inferences. When a toy does not work, or a squeeze ball squeaks, even babies weigh data and make informed bets about why. The results are forming the basis for a new understanding of one of the most distinctive traits of the human mind — the ability to make, test, and continually adjust ideas about how one thing causes another. Such insights could help classroom teachers. “We start with these newborn babies and by the time they’re 4 years old, they have a lot of common sense knowledge about the world. They have ideas about physics, they have ideas about other people, they have ideas about causal relationships,’’ said Laura Schulz, associate professor of cognitive sciences at the Massachusetts Institute of Technology. “The way we get the world right is by making bets — based on probabilities, given the evidence.’’ © 2011 NY Times Co.

Keyword: Development of the Brain; Learning & Memory
Link ID: 15146 - Posted: 03.29.2011

By MURRAY CARPENTER The latest skirmish in the caffeine wars — this one involving the high levels of caffeine in so-called energy drinks, especially those consumed by children — recalls one of the earliest. It happened a century ago this month, in a courtroom in Chattanooga, Tenn. The trial grabbed headlines for weeks and produced scientific research that holds up to this day — yet generated no federal limits for caffeine in foods and beverages. Those levels remain virtually unregulated today. As two researchers recently wrote in The Journal of the American Medical Association, nonalcoholic energy drinks “might pose just as great a threat to individual and public health and safety” as alcoholic ones, and “more research that can guide actions of regulatory agencies is needed.” Nobody used the term “energy drink” in 1911, but the drink that was on trial in Chattanooga contained as much caffeine as a modern Red Bull — 80 milligrams per serving. The drink was Coca-Cola. Harvey Washington Wiley, the “crusading chemist” who led the Bureau of Chemistry in the United States Department of Agriculture, had brought a lawsuit against the Coca-Cola Company, accusing it of adulterating the drink by adding a harmful ingredient: caffeine. (Current levels of caffeine in a Coke are much lower.) © 2011 The New York Times Company

Keyword: Drug Abuse; Sleep
Link ID: 15145 - Posted: 03.29.2011

By TARA PARKER-POPE More than 10 million Americans suffer from anorexia, bulimia and other eating disorders. And while people tend to think such problems are limited to adolescence and young adulthood, Judith Shaw knows otherwise. A 58-year-old yoga instructor in St. Louis, Ms. Shaw says she was nearing 40 when she decided to “get healthy” after having children. Soon, diet and exercise became an obsession. “I was looking for something to validate myself,” she told me. “Somehow, the weight loss, and getting harder and firmer and trimmer and fitter, and then getting recognized for that, was fulfilling a need.” Experts say that while eating disorders are first diagnosed mainly in young people, more and more women are showing up at their clinics in midlife or even older. Some had eating disorders early in life and have relapsed, but a significant minority first develop symptoms in middle age. (Women with such disorders outnumber men by 10 to 1.) Cynthia M. Bulik, director of the Eating Disorders Program at the University of North Carolina, Chapel Hill, says that though it was initially aimed at adolescents, since 2003 half of its patients have been adults. “We’re hearing from women, no matter how old they are, that they still have to achieve this societal ideal of thinness and perfection,” she said. “Even in their 50s and 60s — and, believe it or not, beyond — women are engaging in extreme weight- and shape-control behaviors.” © 2011 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 15144 - Posted: 03.29.2011

by Rebecca Kessler Fear of heights can drive people to extremes, from crossing the country by bus to avoid flying to commuting extra hours every week to circumvent a high bridge. A new study now suggests one counterintuitive path to relief: The human stress hormone cortisol seems to improve the effectiveness of behavioral therapy to help people overcome their fear of heights. The standard treatment for many phobias involves exposing someone to the source of their fear in a safe environment—either in real life or, increasingly, using virtual reality. When nothing bad happens, that person gradually learns that the source—whether it's heights, snakes, or enclosed spaces—is safe. In a process called "extinction," new memories of safe experiences prevail over ingrained memories of scary ones. The treatment works, but it can take many repetitions to stick and is unpleasant enough that some patients drop out. So researchers have been looking for drugs that might be used in combination with extinction-based therapy and can help speed it up. One drug called D-cycloserine, which helps new memories form, is being tested in clinical trials in people with certain phobias. But human and animal studies have shown that hormones released during stressful situations go one step further, not only promoting the creation of new "safe" memories but also inhibiting fear memories, says cognitive neuroscientist Dominique de Quervain of the University of Basel in Switzerland, who lead the present study, published today in the Proceedings of the National Academy of Sciences. © 2010 American Association for the Advancement of Science.

Keyword: Emotions; Hormones & Behavior
Link ID: 15143 - Posted: 03.29.2011

By Randy Dotinga MONDAY, March 28 (HealthDay News) -- Memories of devastating heartbreaks appear to trigger activity in the brain that's similar to when people suffer physical pain, new research suggests. "This tells us how serious rejection can be sometimes," said study author Edward E. Smith, director of cognitive neuroscience at Columbia University. "When people are saying 'I really feel in pain about this breakup,' you don't want to trivialize it and dismiss it by saying 'It's all in your mind.'" The finding could lead to more than a better understanding of the link between emotional and physical pain, Smith said. "Our ultimate goal is to see what kind of therapeutic approach might be useful in relieving the pain of rejection." Previous research has shown a link between what Smith calls "socially induced pain" -- the kind you get from dealing with other people -- and physical pain. For the new study, Smith and colleagues looked at rejection specifically. "From everyday experience, rejection seems to be one of the most painful things we experience," Smith said. "It seems the feelings of rejection can be sustained even longer than being angry." But where do you find rejected people? In New York City, of course, where hundreds or even thousands of relationships must fall apart every day. The researchers advertised online and in newspapers in search of people whose romantic partners had broken up with them. In all cases, they hadn't wanted the breakups to happen. © 2011 U.S.News & World Report LP

Keyword: Emotions; Pain & Touch
Link ID: 15142 - Posted: 03.29.2011

By Michelle Andrews, In any given year, more than a quarter of U.S. adults have a diagnosable mental health problem — from depression to bipolar disorder — yet fewer than half get any kind of treatment for it. The figures are similar for children. Many who do receive care get it through their primary-care physician rather than a mental health professional like a psychiatrist or psychologist. That’s partly by choice: People prefer to talk to someone they know and trust about medical problems, and for many, there’s still a stigma in seeing a “shrink.” But part of the reason people turn to their primary-care doctors or go without care is that it can be tough to get an appointment with a mental health expert. Psychiatrists, in particular, are in short supply, especially in rural areas. A recent survey conducted for the Tennessee Psychological Association, for example, found that the average wait to see a psychiatrist for a non-emergency appointment was 54 days for patients with private health insurance and 90 days for those covered by TennCare, the state’s Medicaid program, says Lance Laurence, director of professional affairs for the TPA. “It’s a huge access issue,” says Katherine Nordal, executive director for professional practice at the American Psychological Association, a trade group for psychologists. Psychologists say they have a solution to help address the access problems: Give them more authority to prescribe psychotropic medications. They can already prescribe in New Mexico and Louisiana, as well as in all branches of the military and the Indian Health Service. A half-dozen other states are considering measures that would give more psychologists prescribing authority. © 1996-2011 The Washington Post

Keyword: Depression
Link ID: 15141 - Posted: 03.28.2011

By JESSE LICHTENSTEIN One day in the fall of their sophomore year, Matthew Fernandez and Akash Krishnan were at Akash’s house in Portland, Ore., trying to come up with an idea for their school’s science fair. At Oregon Episcopal School, all students in 7th to 11th grade are required to enter a project in the Aardvark Science Expo (the aardvark is the school’s mascot), and these two had teamed up for the last three years. Temporarily defeated, they popped in a DVD of “I, Robot.” There’s a scene in the movie when Will Smith, who plays a robot-hating cop, visits Bridget Moynahan, the impossibly gorgeous scientist, and they begin to argue. She gets angry. Her personal robot immediately walks into the room and asks: “Is everything all right, Ma’am? I detected elevated stress patterns in your voice.” It’s a minor exchange — a computer recognizing emotion in a human voice — in a movie full of futuristic robots wreaking havoc, but it was an aha moment for a desperate research team. Their reaction, as Matt describes it, was: “ ‘Hey, that’s really cool. I wonder if there’s any science there.’ ” There was — it was just really hard. With emotion recognition, they stumbled onto a thorny problem. Computers have become very good at parsing an audio signal into specific words and identifying their meaning. But spoken language is more than just semantics. “If I say ‘happy’ and you say ‘happy,’ it’ll sound kind of similar, and a computer can try to match that up,” Matt explains. But it’s far from clear what elements in an audio signal indicate happiness or anger as a quality of voice. Trying to figure that out quickly consumed them. Matt stayed up late reading research papers, ignoring his other homework. Akash was up until 3 a.m. many nights, reading and programming. They spent long hours at each other’s houses or talking on Skype. © 2011 The New York Times Company

Keyword: Emotions; Robotics
Link ID: 15140 - Posted: 03.28.2011

By JEFF Z. KLEIN The debate in the N.H.L. over how to curb concussions is only the latest example of tensions between liberal and traditional forces that have shaped hockey since its beginnings in 19th-century Canada. Montreal's former star Ken Dryden has urged the N.H.L. to ban all hits to the head. The extremes in the current standoff include general managers, sponsors and fans who favor a ban on hits to the head and their old-school counterparts who see such a drastic rule change as potentially robbing the league of its rugged appeal just when its popularity is growing. “The nature of the game is always being changed, but the rules, regulations, understandings and mythologies don’t change,” Ken Dryden, the Hall of Fame goalie from the Montreal Canadiens, said in describing the traditionalist impulse. “That’s when you get into trouble,” he added, “when you don’t recognize the immense changes on one side, and don’t have the corresponding changes that make sense to the different game that evolves.” Dryden broke his long silence on hockey matters this month, joining the team sponsors Air Canada and Via Rail, and the team owners Mario Lemieux of Pittsburgh and Geoff Molson of Montreal in urging the league’s general managers to recommend a prohibition of all hits to the head. The International Ice Hockey Federation, the N.C.A.A. and the Ontario Hockey League — all feeder organizations to the N.H.L. — have bans. © 2011 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 15139 - Posted: 03.28.2011

By Emma Brennand Cuckoos' egg forgery skills are increasingly being put to the test, as host birds evolve better defences, say scientists. These brood parasites, as they are called, are master deceivers - hiding their eggs in other species' nests. To avoid detection, cuckoos have evolved to mimic colour and pattern of their favoured host birds' eggs. But researchers have developed "bird's-eye view" models to find out how the hosts see the intruders' copycat eggs. If host birds do not reject cuckoo eggs, the newly hatched cuckoo chick ejects other eggs from the nest by hoisting them onto its back and dumping them over the edge. This study revealed details about the "evolutionary arms race" in which cuckoos are embroiled; as they evolve better mimicry, their hosts evolve the skills to spot these damaging intruders. Mary Caswell Stoddard and Martin Stevens from the Department of Zoology at the University of Cambridge, UK, published their findings in the journal Evolution. Previous egg pattern research has focused on assessing differences between colour and markings based on human visual inspection."But birds have better colour vision than humans do," Ms Stoddard told BBC News. BBC © MMXI

Keyword: Evolution; Vision
Link ID: 15138 - Posted: 03.28.2011

By Rachel Ehrenberg Navy sonar unquestionably disturbs beaked whales, concludes a new analysis investigating how underwater sound affects these elusive deep-divers. The results, published online March 14 in PLoS ONE, suggest that the current noise levels deemed risky for beaked whales need to be lowered. During sonar exercises at the U.S. Navy’s underwater test range in the Bahamas, beaked whales stopped their chirpy echolocations and fled the area, experiments employing a huge array of underwater microphones revealed. Other experiments that exposed tagged whales to increasing levels of sound found that at exposures of around 140 decibels, the animals stopped hunting for food and slowly swam toward the surface, heading north toward the only exit of the deepwater basin known as the Tongue of the Ocean. Current regulations rate underwater exposures of about 160 decibels as disturbing. “It seems beaked whales may be more sensitive than other species to sound,” says study leader Peter Tyack of the Woods Hole Oceanographic Institution in Massachusetts. “At the very least we may need a special rule for these whales,” he says. “If the criteria are changed they will be more protected.” Until a few different species of beaked whales started showing up in unusual mass strandings, the animals were understudied and rarely seen. Because the strandings often coincided with nearby naval sonar exercises, scientists suspected sonar was somehow driving these whales to the beach. And strange bubbles in the bodies of some of the whales suggested that sonar might trigger behavior that gave the whales the equivalent of the bends. © Society for Science & the Public 2000 - 2011

Keyword: Hearing
Link ID: 15137 - Posted: 03.26.2011

By Janet Raloff Obesity subtly diminishes memory and other features of thinking and reasoning even among seemingly healthy people, an international team of scientists reports. At least some of these impairments appear reversible through weight loss. Researchers also report one likely mechanism for those cognitive deficits: damage to the wiring that links the brain’s information-processing regions. A number of studies in recent years have shown that individuals with diseases linked to obesity, including cardiovascular disease, hypertension and type 2 diabetes, don’t score as well on cognitive tests as less hefty individuals do. To test whether weight alone — and not disease — might be partially responsible, John Gunstad of Kent State University in Ohio and his colleagues recruited 150 obese individuals for a series of cognitive tests. These people weighed on average just under 300 pounds, although some were substantially heavier. Two-thirds would shortly undergo weight-loss surgery. Scores on the tests were assessed against those of people in the Brain Resource International Database, a large multicenter project with data on very healthy people. Obese individuals in the new study initially performed on the low end of the normal range for healthy individuals from the database on average, Gunstad says, although nearly one-quarter of the obese participants’ scores on memory and learning actually fell within what researchers consider the impaired range. © Society for Science & the Public 2000 - 2011

Keyword: Obesity
Link ID: 15136 - Posted: 03.26.2011

by Carl Zimmer Teenagers are a puzzle, and not just to their parents. When kids pass from childhood to adolescence their mortality rate doubles, despite the fact that teenagers are stronger and faster than children as well as more resistant to disease. Parents and scientists alike abound with explanations. It is tempting to put it down to plain stupidity: Teenagers have not yet learned how to make good choices. But that is simply not true. Psychologists have found that teenagers are about as adept as adults at recognizing the risks of dangerous behavior. Something else is at work. Scientists are finally figuring out what that “something” is. Our brains have networks of neurons that weigh the costs and benefits of potential actions. Together these networks calculate how valuable things are and how far we’ll go to get them, making judgments in hundredths of a second, far from our conscious awareness. Recent research reveals that teen brains go awry because they weigh those consequences in peculiar ways. Some of the most telling insight into the adolescent mind comes not from humans but from rats. Around seven weeks after birth, rats hit puberty and begin to act a lot like human teens. They start spending less time with their parents and more with other adolescent rats; they become more curious about new experiences and increasingly explore their world. Teenage rats also develop new desires. It’s not just that they get interested in sex but also that their landscape of pleasure goes through an upheaval. Miriam Schneider, a behavioral pharmacologist who studies adolescence at the University of Heidelberg, and her colleagues recently documented this shift. © 2011, Kalmbach Publishing Co.

Keyword: Development of the Brain
Link ID: 15135 - Posted: 03.26.2011

Matt Kaplan It seems that the constant threat of predation could have a more subtle effect on prey animals than first thought. Female birds that are exposed to predators while they are ovulating produce smaller offspring than unexposed females, researchers have found. The chicks may be smaller, but surprisingly, their wings grow faster and longer than those of chicks from unexposed mothers — an adaptation that might make them better at avoiding predators in flight. The mere presence of a predator can change the behaviour of prey animals. Numerous studies show that birds which are frequently presented with predators increase their nest-defence behaviours and usher their youngsters out of the nest faster, presumably to stop them from being sitting ducks. Yet a new study by Swiss ecologists suggests that predator effects could go beyond behaviour, to physiology. In a previous study in 20051, when ovulating female barn swallows (Hirundo rustica) were presented with models of predators, researchers found that their eggs contained higher than normal levels of corticosterone, a stress hormone. A follow-up examination showed that increased corticosterone reduced egg hatchability and led to fledglings being smaller. However, no one was sure whether this was simply the negative effects of stress or an adaptive response to help offspring cope better with intense predator presence. Keen to tease apart this problem, evolutionary ecologists Michael Coslovsky and Heinz Richner at the University of Bern in Switzerland studied a natural population of ovulating great tits (Parus major) nesting in Bremgartenwald forest near Bern. © 2011 Nature Publishing Group,

Keyword: Stress
Link ID: 15134 - Posted: 03.26.2011

Helen Thomson, biomedical news editor A paralysed woman was still able to accurately control a computer cursor with her thoughts 1000 days after having a tiny electronic device implanted in her brain, say the researchers who devised the system. The achievement demonstrates the longevity of brain-machine implants. The woman, for whom the researchers use the pseudonym S3, had a brainstem stroke in the mid-1990s that caused tetraplegia - paralysis of all four limbs and the vocal cords. In 2005, researchers from Brown University in Providence, Rhode Island, the Providence VA Medical Center and Massachusetts General Hospital in Boston implanted a tiny silicon electrode array the size of a small aspirin into S3's brain to help her communicate better with the outside world. The electrode array is part of the team's BrainGate system, which includes a combination of hardware and software that directly senses the electrical signals produced by neurons in the brain which control the planning of movement. The electrode decodes these signals to allow people with paralysis to control external devices such as computers, wheelchairs and bionic limbs. In a study just published, the researchers say that in 2008 - 1000 days after implantation - S3 proved the durability of the device by performing two different "point-and-click" tasks by thinking about moving a cursor with her hand. © Copyright Reed Business Information Ltd.

Keyword: Robotics
Link ID: 15133 - Posted: 03.26.2011

by Jacob Aron The latest generation of 3D technology has seen mixed success at the cinema, and 3D TVs are yet to establish themselves in the living room. Perhaps the true home of 3D is on mobile devices, where you don't even need special glasses. New Scientist takes a look at the future of 3D on the move. How can you have 3D without glasses? Simple – you do it all the time. We perceive the world in three dimensions because our eyes see two slightly different images and our brain interprets the difference as depth. Films or games displayed on an ordinary 2D screen don't contain any of that depth information, so we perceive them as flat surfaces. Traditional 3D screens add depth information back in by simultaneously displaying or rapidly alternating between two images, relying on viewing glasses to show the separate images to each eye. The red and cyan filters of the original 3D specs have now been replaced by the polarised light systems used in cinemas or active shutter glasses for 3D TVs, but the principle is much the same. Everyone would like to get rid of those 3D glasses, which is why screen manufacturers are researching two other techniques. Parallax barriers add a slotted barrier in front of the screen: each slot reveals a thin strip of the screen to one eye while the adjacent barrier blocks it from the other, so that all the slots together create separate images for each eye. Another technology, lenticular lenses, achieves the same effect with columns of bumpy lenses that redirect light to each eye – you might have once owned a ruler that used a very basic version to make moving or 3D images. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 15132 - Posted: 03.26.2011

By Laura Sanders When courting, male mice lacking the chemical messenger serotonin don’t seem to care whether the object of their affection is female. Mice without the neurotransmitter no longer eschew the smells of other males, wooing them instead with squeaky love songs and attempts to mount them, researchers report online March 23 in Nature. Serotonin’s surprise role in mouse courtship may lead to a deeper understanding of how brain cells control a complex behavior. “Nobody thought that serotonin could be involved in this kind of sexual preference,” says study coauthor Zhou-Feng Chen of Washington University School of Medicine in St. Louis. Scientists emphasize that the male-male courtship seen in the lab isn’t equivalent to human homosexuality. And what, if anything, serotonin has anything to do with human sexual behavior is still an open question. “We have to be cautious because this is work done in mice,” Chen says. “I would be extremely careful to extrapolate these results into humans. We just don’t know much about this.” In the study, male mice that were genetically engineered to lack serotonin-producing brain cells still courted females. But when given the choice between males or females, these mice no longer reliably chose females over males. In tests where both a male and a female mating partner were present, nearly half of the serotonin-lacking males mounted the male first, report researchers led by Yi Rao of the National Institute of Biological Sciences and Peking University in Beijing. © Society for Science & the Public 2000 - 2011

Keyword: Sexual Behavior
Link ID: 15131 - Posted: 03.24.2011

by Shanta Barley Female hamadryas baboons may be vulnerable to a form of domestic violence from which they feel unable to escape – even if they have the opportunity. Most large papionin monkeys – a group including macaques, baboons and mandrills – rely on wandering males to disperse genes through the population. But studies suggest that gene flow through populations of hamadryas baboons (Papio hamadryas) in north-east Africa is mainly through females – even though males keep tight control of them and punish wanderers through vicious biting. In 1968, biologist Hans Kummer suggested that females move when they are abducted by another male – but only now have biologists observed such abductions. Mathew Pines at the Filoha Hamadryas Project in Addis Ababa, Ethiopia, witnessed three abductions between 2007 and 2009. Each time, the original male embarked on an often bloody rescue mission to locate and retrieve the female. Larissa Swedell at the City University of New York, Pines's co-author on the new study, speculates that abduction is not considered a "fair" way to gain a new female, and so the loss isn't accepted by the original male. The rescue missions were helped by the females, who willingly returned to the rescuer despite a history of violent treatment by that male. "The bond is so strong that a female will run to her male when she is frightened, even if he is the source of the threat," says Swedell. © Copyright Reed Business Information Ltd.

Keyword: Aggression; Sexual Behavior
Link ID: 15130 - Posted: 03.24.2011