by Emily Underwood In the Hans Christian Andersen tale "The Nightingale," a songbird melts an emperor's heart with its singing, but flies away when the ruler forces it to sing duets with a jeweled, mechanical bird that warbles only waltzes. There's a moral here, a new study suggests. Although humans have long attributed musical qualities to birdsong, cold, hard statistics show that's all an illusion. The birds we prize most for their songs sound most like the human voice, says Robert Zatorre, a cognitive neuroscientist at McGill University in Montreal, Canada, who was not involved in the study. The sounds they make have clear tones, repeat similar phrases, and are made of discrete notes. Despite these pleasing attributes, however, it has never been scientifically proven that the notes in birdsong follow the same organizational rules that govern most musical compositions. In fact, says ecologist Marcelo Araya-Salas of New Mexico State University in Las Cruces, author of the new study, no one has ever addressed the question using quantitative methods. Billions of potential notes exist between the low and high notes in an octave. But for reasons that researchers only partially understand—the physiological limits of human hearing, for example, and cultural preferences that have evolved over time—most music is based on variations of only five to 12 notes. A baby grand piano, which has 88 keys, is tuned so that each octave is divided into twelve equal intervals, called half-steps, that form the 12-note chromatic scale underlying most of Western music. The seven-note diatonic scale, "do, re, mi, fa, so, la, ti (do)," is another familiar example, as is the ancient five-note, pentatonic scale used in Greek lyre music and nearly every riff played on the electric guitar. © 2010 American Association for the Advancement of Science

Keyword: Animal Communication; Aggression
Link ID: 17172 - Posted: 08.16.2012

By Rick Nauert PhD Senior News Editor Most of us take the ability to read and write for granted. For some, however, these fundamental skills are difficult to master. Sadly, factors associated with the variety of symptoms that contribute to a diagnosis of dyslexia have remained obscure. New research may change this picture as researchers announce a major advancement toward understanding the cause of dyslexia. Neuroscientist Begoña Díaz, Ph.D., and her colleagues at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, have discovered an important neural mechanism underlying dyslexia. They believe problems arise in the part of the brain called the medial geniculate body in the thalamus. Experts believe this discovery can provide the basis for developing potential treatments for the condition. People who suffer from dyslexia have difficulties with identifying speech sounds in spoken language. For example, while most children are able to recognize whether two words rhyme even before they go to school, dyslexic children often cannot do this until late primary school age. Most people suffer from dyslexia for their whole lives although many learn to compensate. Experts say that between five and 10 percent of children suffer from dyslexia, yet very little is known about its causes. © 1992-2012 Psych Central

Keyword: Dyslexia
Link ID: 17143 - Posted: 08.11.2012

By Lara Salahi Can one head injury lead to Alzheimer’s? New research suggests one moderate to severe head injury can disrupt the proteins that regulate an enzyme associated with Alzheimer’s disease. Researchers from Tufts University School of Medicine and Harvard Medical School first measured protein levels in the brains of mice two days after they had incurred moderate to severe head trauma. The researchers found a reduction in the levels of two proteins, GGA1 and GGA3, and an increased level of the enzyme BACE1, which has previously been associated with Alzheimer’s disease. Researchers analyzed Alzheimer’s patients’ brain tissue and found the same protein reduction and enzyme level increase the mice had experienced. The findings suggest that a single brain injury could significantly increase the risk of developing Alzheimer’s disease, according to the researchers. BOTTOM LINE: A moderate to severe head injury can disrupt the proteins that regulate an enzyme associated with Alzheimer’s. CAUTIONS: The study does not look at the long-term effects of enzyme disruption after a traumatic brain injury and whether it leads to the development of Alzheimer’s disease. WHERE TO FIND IT: Journal of Neuroscience, July issue © 2012 NY Times Co.

Keyword: Alzheimers; Aggression
Link ID: 17135 - Posted: 08.07.2012

by Douglas Heaven Watch where you look – it can be used to predict what you'll say. A new study shows that it is possible to guess what sentences people will use to describe a scene by tracking their eye movements. Moreno Coco and Frank Keller at the University of Edinburgh, UK, presented 24 volunteers with a series of photo-realistic images depicting indoor scenes such as a hotel reception. They then tracked the sequence of objects that each volunteer looked at after being asked to describe what they saw. Other than being prompted with a keyword, such as "man" or "suitcase", participants were free to describe the scene however they liked. Some typical sentences included "the man is standing in the reception of a hotel" or "the suitcase is on the floor". The order in which a participant's gaze settled on objects in each scene tended to mirror the order of nouns in the sentence used to describe it. "We were surprised there was such a close correlation," says Keller. Given that multiple cognitive processes are involved in sentence formation, Coco says "it is remarkable to find evidence of similarity between speech and visual attention". Word prediction The team used the discovery to see if they could predict what sentences would be used to describe a scene based on eye movement alone. They developed an algorithm that was able to use the eye gazes recorded from the previous experiment to predict the correct sentence from a choice of 576 descriptions. © Copyright Reed Business Information Ltd.

Keyword: Language
Link ID: 17087 - Posted: 07.25.2012

By Travis Riddle In the final hand of the 2011 World Series of Poker, Pius Heinz, a 22-year-old German who had honed his poker chops online was matched up against 35-year-old Martin Staszko – a former Hyundai automobile plant foreman. Staszko was in bad shape, having only about a quarter of the chips his younger opponent had, and had been dealt a relatively mediocre hand. Despite this, he decided to risk it all in an attempt to wage a comeback. In effect, he was lying, and Heinz, fortunately blessed with a relatively good hand, called him on his lie. Heinz, having successfully detected his opponents attempt at deceit, won the hand, the tournament, and $8.7 million while Staszko, the failed deceiver, took runner up and had to console himself with just $5.4 million. Although humans are the only species that plays poker, we are far from the only species that uses deception. And though several million dollars may seem like a high stakes game to us, the stakes for animals which use deception are even higher – often life or death. A frog which successfully fakes its croak to make itself seem bigger will be more likely to succeed in life than a similarly sized one which unsuccessfully fakes its croak. However, the ability to detect deception is just as important as the ability to deceive. A female frog with a talent for detecting deception will be more likely to mate with the actual biggest frog in the pond, rather than the one which only sounds the biggest, ensuring a greater likelihood of success for her genes. And so the evolutionary arms race continues, with liars and lie detectors successively attempting to one-up each other in reproductive fitness. © 2012 Scientific American,

Keyword: Emotions; Aggression
Link ID: 17086 - Posted: 07.25.2012

A simple insole could help people who've survived a stroke to regain their balance. When someone suffers a stroke, one side of the body can be weakened, which raises the possibility of unstable walking and debilitating falls. Physiotherapists try to help patients learn to shift their body weight slightly to the weaker side that's been affected by the stroke to regain their balance, but it doesn't always work well. When the lower extremities and muscles are weakened after a stroke, people often learn how not to use that side of the body, even after they've recovered a bit, said Alexander Aruin, a physical therapy professor at the University of Illinois at Chicago. Aruin, who has a background in engineering, invented an insole that when fitted into a patient's shoe slightly lifts and tilts the body toward the stroke-affected side to restore balance. Physical therapy for stroke aims to help patients learn to shift their body weight slightly to the weaker side.Physical therapy for stroke aims to help patients learn to shift their body weight slightly to the weaker side. (Kim Kyung Hoon/Reuters) The device is used in conjunction with physical therapy to help people learn to bear weight equally through both legs and improve their strength and maintain balance. In a study, Aruin's team gave the insoles to individuals with stroke for six weeks and compared them to a control group who did not receive the insoles but did do physiotherapy. © CBC 2012

Keyword: Stroke
Link ID: 17071 - Posted: 07.21.2012

By Marissa Fessenden Autistic children struggle with many obstacles, including learning to speak. And, experts have noted, if these children learn verbal skills by age five, they tend to become happier and higher-functioning adults than do their nonverbal peers. Thirty years ago, psychiatrists expected only half of all autistic children would gain speaking abilities. Recent studies, however, indicate that as many as 80 percent of children with autism can learn to talk. One such study in 2006 showed that toddlers who received intensive therapy aimed at developing foundational oral language skills made significant gains in their ability to communicate verbally. Now researchers have followed up with a number of those kids and found that most of them continued to reap the benefits of that therapy years after it had ended. Several early behaviors build a foundation for language. These abilities have also been linked to whether a child can anticipate another person's mental state and use that understanding to explain and predict behavior. Developing this "theory of mind" may be a central difficulty for children with autism. Kasari's team targeted two of the early behaviors in their work: The first is the ability to engage in symbolic play, in which one object represents another—a child pretending a doll is his parent, for instance. The second is joint attention, wherein a child divides focus between an object and another person. This behavior can be thought of as "sharing looks." For example, when a child points to show a playmate a toy train, she looks at the moving train and checks to see if her playmate is engaged. In the initial study, Connie Kasari of the University of California, Los Angeles, and her colleagues evaluated 58 children between three and four years old in a randomized controlled study. © 2012 Scientific American,

Keyword: Autism; Aggression
Link ID: 17057 - Posted: 07.18.2012

By GRETCHEN REYNOLDS Much has been studied and reported, particularly in this newspaper, about the short-term effects of concussions on young athletes, as well as the potential longer-term outcomes for professional athletes who engage in high-level contact sports like football and ice hockey for many years, putting themselves at risk for multiple concussions and the lesser but still consequential subconcussive injuries. But until recently, far less has been understood about the long-term implications, if any, of concussions experienced years ago by recreational athletes. Does a 55-year-old man who played high school football in the ’70s and perhaps grew dizzy or “had his bell rung” after a tackle or two need to worry about the state of his brain today, even if he never had a formal diagnosis of concussion? Or do I, because I bounced my head hard against the slopes several times while learning to snowboard 10 years ago? The emerging answer, according to recent research, would seem to be a cautious “probably not,” although there may be reason to monitor how easily names and places come to mind. For a study published in May in the journal Cerebral Cortex, researchers at the University of Montreal examined the brains of a group of healthy, middle-aged former athletes, all of whom had played contact sports in college about 30 years ago and some of whom had sustained concussions while doing so. In the years since, the athletes had stopped competing but had remained physically active. None complained of failing memories or other symptoms of cognitive impairment — or at least, not more so than any group of 50- and 60-year-olds would be expected to complain. Copyright 2012 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 17029 - Posted: 07.12.2012

By Ruth Williams If a child you know refuses to share his toys, chances are he knows he is doing wrong but cannot help it. New research published in March in Neuron reveals that underdevelopment of an impulse control center in the brain is, at least in part, the reason children who fully understand the concept of fairness fail to act accordingly. As babies, we are inherently selfish, but as we grow, we become better at social strategy—that is, satisfying our own needs while behaving in a manner acceptable to others. Nikolaus Steinbeis of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, wondered how this skill develops. Steinbeis and his team examined kids aged six to 14 performing two similar decision-making tasks that involved sharing poker chips with an anonymous recipient (the chips were redeemable for prizes). In task one, the size of a child's offering carried no consequences, but in the second task, the anonymous youngster could reject the offer, if he or she considered it unfair, and both children would get nothing. Task two thus required social strategy; task one did not. In task one, older and younger children behaved similarly. But in task two, younger children both made worse offers and were more willing to accept bad offers even though they understood that these offers were unfair. Imaging the kids' brains while they performed the tasks revealed less activity in the younger kids' impulse-control regions in their prefrontal cortex, the seat of decision making and self-control in the brain. In addition, independent of age, less activity in this region paralleled less social strategy. © 2012 Scientific American,

Keyword: Development of the Brain; Aggression
Link ID: 17014 - Posted: 07.09.2012

By Sandra G. Boodman, Of course Diane O’Leary was seriously tired — who wouldn’t be? A doctoral candidate in philosophy with a demanding academic schedule and a 3-year-old son, O’Leary had flown home to Sydney after her family’s annual visit to relatives in Upstate New York. A few days after that 1994 flight, when O’Leary had to stop in the middle of a dance class because she was too exhausted to continue, she chalked it up to bad jet lag. And a week or so later, when she couldn’t walk up a small hill with her son without stopping to rest on a bench, the 33-year-old wasn’t alarmed. “I managed to get myself through it,” she recalled, adding that she was accustomed to being somewhat tired. But a few weeks later, when the exhaustion didn’t recede, O’Leary consulted her general practitioner. He sent her to a specialist, who made a worrisome diagnosis that would prove to be the first of many wrong answers: chronic fatigue syndrome, an illness that is not relieved by rest. Several months later, after she developed joint pain along with the fatigue, doctors decided she had rheumatoid arthritis, a serious inflammatory disorder that can cause joint destruction. The following year, that diagnosis was jettisoned in favor of a severe form of lupus, an autoimmune disease in which the body attacks its own tissues. But after medications that are the mainstay of treating lupus had no effect — and she developed strange new symptoms — O’Leary’s doctors shifted focus, suggesting that she was also suffering from an underlying psychological disorder. She said she remembers one doctor telling her, “You’re just nervous, honey.” © 1996-2012 The Washington Post

Keyword: Stroke; Aggression
Link ID: 16995 - Posted: 07.03.2012

by Andy Coghlan One of the key elements of memory – how we store and retrieve words according to what they mean – has been unravelled by analysing electrical signals from people's brains while they recalled lists of words. Although the discovery cannot identify the individual words being filed, which could effectively make a very basic form of mind-reading possible, it does for the first time reveal the electrical circuitry vital for storing words according to what they mean, rather than where they came in a sequence, for example. "Our main focus is on how people organise their memories," says Jeremy Manning, currently at Princeton University. "So we looked at the degree to which people organised their memories according to the meanings of words." Calling Roget The researchers recruited 46 patients with epilepsy who had already had electrodes implanted in their brains for treatment purposes. The electrodes allowed the researchers to measure electrical activity in the brain as the participants viewed lists of 15 to 20 words. A minute later, the patients were asked to recall aloud as many as possible, in any order. Collectively, the participants viewed 1550 lists, including a total of 24,760 words. The researchers included within each list words with similar meanings or associations, such as "goose" and "duck", to see if recall of one prompted recollection of the other. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory; Aggression
Link ID: 16987 - Posted: 06.30.2012

WASHINGTON — A Covidien device for rare malformed blood vessels can get stuck in the brain and has been linked to nine patient deaths, U.S. regulators warned. The device, made by Covidien unit ev3, uses a spongy material to block off blood flow to abnormal tangles of blood vessels before they are removed by surgery. The material is delivered to the brain through a tube inserted into a groin artery, known as a catheter. But the catheter can get stuck in the spongy material while inside the brain, causing serious complications including hemorrhage and death, the U.S. Food and Drug Administration said in a notice posted to its website on Thursday. Since the device was approved in 2005, the FDA said it has received more than 100 reports of the catheter breaking after it became stuck, including nine deaths. In at least 54 cases, the catheter could not be removed, leaving it implanted in the patient. "Neither (the spongy material) nor the catheter is intended to be long-term implants, and patients may need additional medical interventions to have the catheter removed if it becomes entrapped," the FDA said in the notice. If the catheter is not removed, parts of it can also migrate to other parts of the body. (c) Copyright Thomson Reuters 2012

Keyword: Stroke
Link ID: 16986 - Posted: 06.30.2012

By Brian Palmer, A friend recently asked me whether black bears in Appalachia have Southern accents and whether they have trouble understanding black bears raised in Canada or Alaska. Taken literally, those are notions more fit for a Disney movie than a scientist. In a more abstract sense, however, it’s a profound inquiry that fascinates zoologists and psychologists alike. Is communication learned or innate in nonhuman animals? Can geographically distant groups of the same species develop local culture: unique ways of eating, playing and talking to each other? I posed those questions to Darcy Kelley, a Columbia University professor who studies animal communications. “In most species, communication appears to have a genetic basis,” she said. “Regional accents can only develop in the small number of species that learn their vocalizations from others.” Research suggests that the overwhelming majority of animals are born knowing how to speak their species’s language. It doesn’t really matter where those animals are born or raised, because their speech seems to be mostly imprinted in their genetic code. University of Pennsylvania psychologist Bob Seyfarth and biologist Dorothy Cheney conducted a classic experiment on this question. They switched a pair of rhesus macaques and a pair of Japanese macaques shortly after birth, so that the Japanese macaque parents raised the rhesus macaque babies, and the rhesus macaque parents raised the Japanese macaque babies. © 1996-2012 The Washington Post

Keyword: Language; Aggression
Link ID: 16973 - Posted: 06.27.2012

By SINDYA N. BHANOO If you’ve heard one pygmy goat kid bleating, you’ve heard them all — unless, that is, you’re a mother goat. A new study reports that mothers can recognize the calls of their kids even after more than a year of separation. In the wild, female goats tend to stay within their groups, while males disperse. For their study, researchers separated the goats after weaning, and found that the mothers remembered the calls of their offspring for 7 to 13 months. The study appears in the journal Proceedings of the Royal Society B. “Mothers responded more to their kids born the previous year than to newborn kids born to other mothers,” said Elodie F. Briefer, an evolutionary biologist at Queen Mary, University of London, and one of the study’s authors. Dr. Briefer and her colleagues recorded kids when they were 5 weeks old, and played the recordings back to the mothers through a loudspeaker later. It isn’t clear why mother goats have this ability, but it could help mothers and daughters stay bonded and prevent mothers from inbreeding with their sons, Dr. Briefer said. “These functions would happen later in life, but the mothers would need to recognize their grown-up kids,” she said. The researchers worked with nine female pygmy goats and their kids at a farm in Nottinghamshire, England. They measured how quickly the goats responded to recorded calls, how many calls they made in response to what they heard, and how long they looked at the loudspeaker. © 2012 The New York Times Company

Keyword: Animal Communication; Aggression
Link ID: 16966 - Posted: 06.26.2012

John von Radowitz A protein needed to re-grow injured nerves in limbs has been identified, raising the prospect of new treatments. The findings, in mice, have implications for helping patients recover from peripheral nerve injuries. They also open up new pathways for investigating how to regenerate neurons in the spinal cord and brain. Peripheral nerves provide the sense of touch and drive the muscles that move the arms, legs and feet. Unlike central nervous system nerves of the spinal cord, they can regrow after being cut or crushed. But how this happens is still not well understood. Scientists conducting the new research, reported in the journal Neuron, identified a signalling protein that helps switch on the regeneration process. The molecule, called leucine zipper kinase (DLK), regulates signals that tell a nerve cell it has been injured, often communicating over distances of several feet. Mice lacking DLK were unable to regrow severed nerves. Lead researcher Professor Aaron DiAntonio, from Washington University in St Louis, US, said: "DLK is a key molecule linking an injury to the nerve's response to that injury, allowing the nerve to regenerate. © independent.co.uk

Keyword: Regeneration; Aggression
Link ID: 16944 - Posted: 06.21.2012

Ewen Callaway Ten years ago, psychiatrist David Skuse met a smart, cheery five-year-old boy whose mother was worried because her son had trouble following conversations with other kids at school. He struggled to remember names and often couldn’t summon the words for simple things such as toothpaste. Skuse is an expert on language development at the Institute of Child Health at University College London, but he had never encountered anything like the boy’s condition. His scientific curiosity was piqued when the mother, who is bilingual, mentioned her own difficulties remembering words in English, her native tongue. Her mother, too, had trouble recounting what had happened in television shows she had just seen. “The family history of this word-finding problem needs further investigation,” Skuse noted at the time. About half the members of this family, dubbed JR, share similar language deficits and brain abnormalities. These deficits seem to be inherited across at least four generations, Skuse and his colleagues report today in Proceedings of the Royal Society B1. Identifying the genetic basis of the family’s unique trait — which they call the ‘family problem’ — could help to explain how our brains link words to objects, concepts and ideas. “It’s like that tip-of-the-tongue moment; you’re struggling to find a word,” says Josie Briscoe, a cognitive psychologist at the University of Bristol, UK, and a study co-author. The researchers tested eight JR family members on a number of language and memory tasks to better understand their deficits. © 2012 Nature Publishing Group,

Keyword: Language; Aggression
Link ID: 16943 - Posted: 06.20.2012

By Jillian Eugenios Yasel Lopez, 16, was fishing with a friend in Miami when their three-foot spear gun went off unexpectedly, piercing Lopez through his head. Doctors are calling his survival from the accident, nearly two weeks ago, a miracle. The gun went off unexpectedly when the teenagers were loading it with a spear, sending it straight into Lopez's skull, Tamron Hall reported on TODAY Monday. The force of the impact was so strong it knocked him into the water. Acting quickly, his friend called 911 and Lopez was soon airlifted to Miami's Jackson Memorial Hospital where doctors raced to save him. Doctors revealed details Monday about Lopez's ordeal, and how they worked to save his life. “We used a high-speed drill to drill the bone at either end to create an opening through which we could remove the spear,” one of the doctors told reporters. They first had to cut the spear to prevent it from moving and allow doctors to do tests. After the spear was cut, doctors said they were able to plan the surgery: “We were able to position him laying with his left side down, right side up, and then we were able to open a large incision." Dr. George Garcia, who helped to save Lopez's life, said that Lopez was awake and interacting with hospital staff when he arrived, though he became agitated and panicky. “We didn't know if that was a result of the injury to his brain or if he was just scared or in a lot of pain.” Dr. Garcia said that that the fact that Lopez was lucid throughout gave the doctors confidence the teenager would survive. © 2012 msnbc.com

Keyword: Brain Injury/Concussion
Link ID: 16938 - Posted: 06.20.2012

By DAVID TULLER Late one evening last December, 18-year-old Michelle Vaquero was crossing a busy street in San Jose, Calif., when a car slammed into her. She landed more than 30 feet away. An ambulance rushed her to Santa Clara Valley Medical Center, where doctors diagnosed traumatic brain injury. Miriam Richards, Ms. Vaquero’s mother, said that doctors at first offered little cause for optimism. “The impact was so severe that they didn’t give us any hope,” she said. “They didn’t tell us she’d be fine. They didn’t know how bad it was.” Ms. Vaquero has been steadily recovering since the accident, and there is reason for Ms. Richards to hope that progress will continue. Shortly after she arrived at the hospital, Ms. Vaquero was enrolled in a study examining whether a surprising new treatment could minimize the damage to her brain: a three-day infusion of progesterone, the reproductive hormone. The study, financed by the National Institutes of Health and overseen by Emory University in Atlanta, is designed to test the hypothesis that the hormone can reduce mortality and disability if administered right after a traumatic brain injury. Patients must begin the infusion within four hours of the injury, with outcomes assessed after six months. The study is one of two large trials of progesterone that have generated excitement among doctors because no medications have been approved for preventing the worst outcomes associated with serious brain injuries. Dr. David Gordon, an assistant professor of neurosurgery at Montefiore Medical Center in the Bronx who is not involved in the research, said that he has “some measure of cautious optimism” about progesterone. © 2012 The New York Times Company

Keyword: Brain Injury/Concussion; Aggression
Link ID: 16933 - Posted: 06.19.2012

By Bill Briggs I had done all my crying weeks before. But pacing a hospital hallway -- as nurses changed the diapers of my silent, blank-faced, 20-year-old daughter in the room behind me -- I asked my wife for a hug. I don’t request many. I try to give more hugs than I get. But that August night, I yearned for the blonde girl lying in the bed 20 feet away, a respiration machine blowing oxygen through a hole cut into her trachea. Advertise | AdChoices “I miss her voice. I miss her laugh,” I told Nancy -- my wife and Andrea’s stepmom -- as she wrapped her arms around me. “I really just miss Andrea.” One month earlier, on July 26, my cell phone rang as I gobbled a final forkful of dinner in my living room. I didn’t recognize the number. A somber woman asked if I was the father of Andrea Briggs and told me, flatly, that Andrea was in a nearby hospital. Now standing, my knees flinched. I held a corner of my desk for support as I peppered the woman with urgent questions that she wouldn’t answer. “Is she alive? Can you just please tell me if my daughter is alive?” I demanded, my voice rising. “She is in very critical condition,” the woman said. “Come to Denver Health Medical Center as soon as possible.” The nauseous pang in my stomach blended with a strange, detached numbness and I felt like I was walking in someone else’s body. I grabbed my car keys, fully believing I was on my way to say goodbye to my only child. © 2012 msnbc.com

Keyword: Brain Injury/Concussion
Link ID: 16915 - Posted: 06.16.2012

by Helen Fields When a male club-winged manakin (Machaeropterus deliciosus) wants to attract a female in the Andean cloud forest, he raises his wings over his back and vibrates a pair of giant feathers to make a "PEEP!" sound (as in video above). A scientist at Cornell University suspected there were odd bones under those strange feathers, so she teamed up with colleagues to do computed-tomography scans of the manakin and some close relatives. Bird bones are hollow, with air pockets that make flight easier. But the club-winged manakin is an oddball. The scans revealed that its humerus, the bone that starts at the shoulder, is solid. The ulna, in the next section of wing, is also solid. It's also just plain wacky: While the other birds' ulnae are long, thin, and smooth with a knob at each end, the club-winged manakin's ulna is shaped like a club and covered with lumps and bumps. (And yet they still manage to fly.) The scientists, who report their findings online today in Biology Letters, think the bumps grasp the ends of the special resonating feathers, which poke through the skin, for better sound control, and that the dense bone may make the sound louder by bouncing it out through the feather. © 2010 American Association for the Advancement of Science

Keyword: Sexual Behavior; Aggression
Link ID: 16906 - Posted: 06.13.2012