By Michael Torrice Add another ill effect to the negative consequences of stress. In addition to making us more irritable, forgetful, and unhealthy, stress also rearranges wiring in the brain, leading to bad decision-making, according to a new study in rats. Rats, like humans, aren't too hard to stress out. Stick them in an enclosed space or make them share a cage with a dominant comrade and the rodents get fairly unnerved. And that, researchers have found, leads to bad choices. Scientists at the University of Minho in Portugal and the U.S. National Institutes of Health (NIH) in Bethesda, Maryland, compared stressed and unstressed rats' responses to two tests. In the first test, they taught the rats to hit a lever to score one of two possible treats: a sip of a sugary solution or a food pellet. The scientists then changed the game, providing the rats with all of the snacks they wanted before giving them the option to press the lever. Satiated, the unstressed rats hit the lever significantly less. But the stressed rats continued pressing at the same rate. For the second test, the scientists trained the rodents to use two levers, one for each treat. After the rats learned the rules, the researchers picked one treat to dispense randomly, whether or not the rat hit the lever. The relaxed animals hit that treat's lever less often, while the stressed rats continued to hit both levers with equal frequency. © 2009 American Association for the Advancement of Science.

Keyword: Stress
Link ID: 13111 - Posted: 06.24.2010

Short-term complications and death rates were low following bariatric surgery to limit the amount of food that can enter the stomach, decrease absorption of food or both, according to the Longitudinal Assessment of Bariatric Surgery (LABS-1). The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. Results are reported in the July 30 issue of the New England Journal of Medicine. Less than 1 percent (0.3 percent) of patients died within 30 days of surgery, further supporting the short-term safety of bariatric surgery as a treatment for patients with extreme obesity. Bariatric surgery can have dramatic health benefits — such as improved blood sugar control or even reversal of type 2 diabetes. But it also carries serious risks, including death. The LABS-1 study aimed to evaluate the short-term safety of bariatric surgery to help doctors and patients understand the risks. "Evaluating the 30-day safety outcomes of bariatric surgery in large populations is an essential step forward," according to co-author Myrlene Staten, M.D. senior advisor for diabetes translation research at NIDDK, part of NIH. "And LABS-1 data are from all patients who had their procedure performed by a surgeon participating in the study, not from just a select few patients." Various types of bariatric surgery limit food intake, nutrient absorption or both. The major types of surgery undergone by participants in this study included laparoscopic adjustable gastric banding, laparoscopic Roux-en-Y gastric bypass and open Roux-en-Y gastric bypass.

Keyword: Obesity
Link ID: 13110 - Posted: 06.24.2010

By Laura Sanders Researchers have whipped up a batch of calorie-burning brown fat cells, a feat which may ultimately lead to new ways to treat obesity and metabolic disorders such as diabetes, a paper published online July 29 in Nature reports. “Brown adipose tissue is coming to the forefront of research in diabetes and obesity because its role is burning energy,” says Francesco Celi, an endocrinologist at the National Institute of Diabetes and Digestive and Kidney Diseases in Bethesda, Md. Unlike energy-storing white fat, brown fat burns energy. Known to keep small animals and dimply babies warm in cold temperatures, brown fat has been shown recently to be present in adults (SN: 5/9/09, p. 10). This finding made researchers think it might be feasible to combat obesity by increasing the amount and activity of brown fat stores in the adult body. Researchers knew that a protein named PRDM16 was important for producing brown fat cells from pre-muscle cells called myoblasts. In the new study, Bruce Spiegelman of the Dana Farber Cancer Institute and Harvard Medical School in Boston, Mass., and his colleagues found that PRDM16 requires a partner, called C/EBP-beta. Either protein on its own had no effect on mouse myoblasts in a lab dish. These myoblasts divided as usual. But when researchers increased the amount of both proteins, cells divided to create functional energy-burning brown fat cells, in addition to copies of themselves. Uncovering this method to make brown fat cells, Spiegelman says, “offers us an opportunity to play with the switch.” © Society for Science & the Public 2000 - 2009

Keyword: Obesity
Link ID: 13109 - Posted: 06.24.2010

By BENEDICT CAREY The sight was not that unusual, at least not for Mosul, Iraq, on a summer morning: a car parked on the sidewalk, facing opposite traffic, its windows rolled up tight. Two young boys stared out the back window, kindergarten age maybe, their faces leaning together as if to share a whisper. The soldier patrolling closest to the car stopped. It had to be hot in there; it was 120 degrees outside. “Permission to approach, sir, to give them some water,” the soldier said to Sgt. First Class Edward Tierney, who led the nine-man patrol that morning. “I said no — no,” Sergeant Tierney said in a telephone interview from Afghanistan. He said he had an urge to move back before he knew why: “My body suddenly got cooler; you know, that danger feeling.” The United States military has spent billions on hardware, like signal jamming technology, to detect and destroy what the military calls improvised explosive devices, or I.E.D.’s, the roadside bombs that have proved to be the greatest threat in Iraq and now in Afghanistan, where Sergeant Tierney is training soldiers to foil bomb attacks. Still, high-tech gear, while helping to reduce casualties, remains a mere supplement to the most sensitive detection system of all — the human brain. Troops on the ground, using only their senses and experience, are responsible for foiling many I.E.D. attacks, and, like Sergeant Tierney, they often cite a gut feeling or a hunch as their first clue. Copyright 2009 The New York Times Company

Keyword: Emotions; Attention
Link ID: 13108 - Posted: 06.24.2010

By MATT RICHTEL The first study of drivers texting inside their vehicles shows that the risk sharply exceeds previous estimates based on laboratory research — and far surpasses the dangers of other driving distractions. The new study, which entailed outfitting the cabs of long-haul trucks with video cameras over 18 months, found that when the drivers texted, their collision risk was 23 times greater than when not texting. The Virginia Tech Transportation Institute, which compiled the research and plans to release its findings on Tuesday, also measured the time drivers took their eyes from the road to send or receive texts. In the moments before a crash or near crash, drivers typically spent nearly five seconds looking at their devices — enough time at typical highway speeds to cover more than the length of a football field. Even though trucks take longer to stop and are less maneuverable than cars, the findings generally applied to all drivers, who tend to exhibit the same behaviors as the more than 100 truckers studied, the researchers said. Truckers, they said, do not appear to text more or less than typical car drivers, but they said the study did not compare use patterns that way. Compared with other sources of driver distraction, “texting is in its own universe of risk,” said Rich Hanowski, who oversaw the study at the institute. Copyright 2009 The New York Times Company

Keyword: Attention
Link ID: 13107 - Posted: 06.24.2010

By Jenny Lauren Lee Over-the-counter allergy medications turn obese, diabetic mice into healthy, normal-weight mice, researchers report. The new research focuses on mast cells, immune system players critical to the inflammatory response involved in allergies. The study appears along with three other independent studies in the July 26 online Nature Medicine that show a connection between type 2 diabetes and the immune system. “Certainly the study is very exciting,” says George King of Harvard University’s Joslin Diabetes Center in Boston, who was not involved in the research. “It’s the first type to identify mast cells as having a potential role in developing obesity.” Researchers from Harvard and their colleagues found that the inflammatory mast cells are as much as six times more abundant in the fat tissue of obese and diabetic humans and mice than in the fat tissue of normal-weight humans and mice. Under certain conditions (such as when a person with allergies inhales pollen), these mast cells leak inflammation-inducing molecules “like a trash bag with holes in it,” says Guo-Ping Shi, a coauthor of the study on mast cells. Anti-inflammatory drugs, such as those used in anti-allergy eye drops and nasal sprays, reduce allergic symptoms by stabilizing the mast cells, effectively putting an extra trash bag around the leaky one so inflammatory molecules can’t be released. Shi says the team was curious about whether pre-existing medicines that stabilize mast cells might also alleviate the symptoms of diabetes. © Society for Science & the Public 2000 - 2009

Keyword: Obesity; Neuroimmunology
Link ID: 13106 - Posted: 06.24.2010

By Tom Jackman Danny Watt once leapt from a moving train. He hurtled through the windshield of a rolling car. Got pummeled by drug dealers. Overdosed. Swallowed rat poison. Tried to hang himself. In his tumultuous 21 years, Danny Watt danced with death in the most amazing, horrible ways. In the end, two college students spotted him facedown in the cold, murky water of the C&O Canal one afternoon in April 2008. The medical examiner said Danny had drowned. It was an end that Danny's parents, Bobby and Mary Watt of Reston, had struggled to stave off for many years. But after refinancing their house three times to put their son in every substance abuse and mental health program imaginable, after going to countless meetings and hearings and hospitals and jails, after badgering every possible person in Fairfax County who might help them, they could not save Danny. "We just went through so much for so long," said Mary Watt, breaking into tears. "We tried and tried for so many years, fighting, only to lose." Danny Watt was a walking symbol of a phenomenon called co-occurring disorders, or dual diagnosis, which is estimated to affect 7 million adults in the United States. These people are both seriously mentally ill and abusing drugs or alcohol. About half of all adults who are seriously mentally ill are also thought to be addicted. The mental health community calls this "self-medication." The federal government estimates that 90 percent of people with co-occurring disorders do not get the treatment they need. © 2009 The Washington Post Company

Keyword: Schizophrenia; Drug Abuse
Link ID: 13105 - Posted: 06.24.2010

By Lynne Peeples in 60-Second Science Blog Give a dog a treat, and she just might learn that new trick. Could the same concept also help a human recover from a brain injury, or become a violin virtuoso? Rewards, especially in combination with drugs that enhance the neurotransmitter dopamine, may boost both cognitive and tactile learning, according to research published today in the journal PLoS Biology. “We have known a lot about reward mechanisms,” says Burkhard Pleger of the Max Planck Institute for Human Cognitive and Brain Sciences and lead author on the study, “but it was not well known how rewards influence sensory processing.” Researchers designed a game to elucidate this process. Prior to each set of four consecutive trials, Pleger and his colleagues showed participants how much reward could potentially be earned (incentives ranged from zero to 80 pennies). Subjects then attempted to distinguish which of two electric currents applied to their index fingers carried a higher frequency. If they were correct, the visual monetary reward was displayed. The higher the reward, Pleger and his colleagues found, the more correct decisions were made on subsequent trials. Subjects appeared to be learning. “They always had the carrot in front of their eyes,” says Pleger. A feedback between the sensory and reward centers, he explains, “optimized brain functions to get the highest possible reward.”

Keyword: Drug Abuse; Learning & Memory
Link ID: 13104 - Posted: 06.24.2010

By Rachel Ehrenberg A blue dye found in Gatorade and Rocket Pops could play a protective role in the cellular mayhem that follows spinal cord injury. In rats, the dye — known as FD&C Blue No.1 — appears to block a molecule that floods the injury site and kills nerve cells, a team reports in the July 28 Proceedings of the National Academy of Sciences. Rats dosed with the dye after injury showed greater improvement in motor skills than rats not receiving the dye. And the food colorant’s low toxicity suggests a new approach for treating spinal cord trauma in humans, injuries for which there are few therapies. “It’s not a cure,” says neuroscientist Maiken Nedergaard of the University of Rochester Medical Center in Rochester, N.Y., who led the new study. “I don’t think that anything can cure this, but for the patient it could be a big improvement.” The results are impressive and realistic, comments Lynne Weaver, a neuroscientist at the Robarts Research Institute in London, Canada. Weaver notes that the side effects of any new potential therapy must be considered, but “the principle is interesting.” ATP, for adenosine triphosphate, is known as the energy currency of cells, and the molecule is used like a battery whenever cells need to get stuff done. But a few years ago Nedergaard and her colleagues reported that ATP has a darker side. It wreaks havoc when the central nervous system is injured, flooding the injury site and hitting a receptor that sits on some immune system cells. ATP binds to this receptor, called P2X7, resulting in a cascade of events that leads to cell death. © Society for Science & the Public 2000 - 2009

Keyword: Regeneration; Brain Injury/Concussion
Link ID: 13103 - Posted: 06.24.2010

By DANA WALTERS In high school, I was a skeleton of who I am now. With pangs of hunger and a jutting rib cage, I was waiting for confidence and determination to flesh me out, fill me and protect me. The story of eating disorders, of young girls starving themselves for the sake of perfection, is a common one, written on the bathroom walls amid the graffiti of rumors and insults. Despite its ubiquity in high school, I believed my hunger was mine alone. Only later did I discover just how truly commonplace my story was. My eating disorder did not make me special. Only curing myself would. I grew up in Swarthmore, Pa., a town not unlike Middlebury, Vt., where I now attend school, but I still thought the substitution of the Green Mountains for the Philadelphia skyline would be just enough to drastically shift my unbalanced psyche. But the deeply instilled sense of overwork and suicidal efficiency still flourished. In Swarthmore, it dotted the driveways of professors, lawyers and doctors, gave nourishment to the soil along the streets named after the most competitive universities in the nation, and resonated in the enthusiasm with which parents flipped through the college announcement edition of the town paper. My new environment, it turned out, was much the same. When I arrived at Middlebury, the beautiful New England buildings screamed of the same hunger for achievement. The competition for perfection was not over. Students glowed with the masochism that drove us to fast ourselves into oblivion. Copyright 2009 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 13102 - Posted: 07.27.2009

PORTLAND, Maine - She was sociable and happy in high school. But in college that changed abruptly: Depressed and withdrawn, some days she couldn't get out of bed. And that wasn't all. "I had really odd thoughts," recalled the woman, now 21, who asked that her name not be used. While walking across campus at the University of Southern Maine, "sometimes I'd feel like people were just right behind me (who might) jump me or something." Story continues below ↓advertisement | your ad here She knew it wasn't true, but she couldn't shake the feeling. Sometimes, while driving, she saw imaginary, shadowy people on the sidewalk. And now and then, out of nowhere, there would be a woman's voice in her ear during class, or random soft noises like knocking or the fizzy hiss of a newly opened soda can. When she visited the university health service and talked about feeling depressed, a nurse practitioner saw another problem: a possible case of schizophrenia in the making. This schizophrenia "prodrome" — the early signs — involves a troubled mental state usually found in teens and young adults. It can lead to psychosis, the loss of touch with reality that marks not only schizophrenia, but also some forms of depression or manic-depression. The prodrome can linger for weeks, or years, before it gives way to psychosis — or mysteriously disappears without a trace. © 2009 The Associated Press.

Keyword: Schizophrenia
Link ID: 13101 - Posted: 06.24.2010

From The Economist print edition LABELS matter. Indeed, they can be the difference between life and death. Someone lying in a hospital bed labelled “minimally conscious state” will be kept on life support indefinitely. If the label says “vegetative state”, however, that life support could be turned off any time. A layman might not be able to tell the difference. But a doctor can. Or can he? A worrying study just published in BioMed Central Neurology by Caroline Schnakers, Steven Laureys and their colleagues at the University of Liège’s coma science group suggests that perhaps he cannot—or, perhaps worse, that he prefers to use his intuition rather than the latest diagnostic techniques to tell the difference. As a result, many people may be at risk of early termination even when they show flickering signs that their consciousness has not departed entirely. Vegetative patients are those who show no signs of awareness whatsoever, and in many countries courts can consider petitions to withdraw their food and water, allowing them to die (as happened in a blaze of publicity in the case of Terri Schiavo, in Florida, a few years ago) and for their organs to be removed for transplantation. Patients who do show signs of awareness—those who are able to obey a command to blink or track a moving object with their eyes, for example—are by definition not vegetative and are spared this fate. There is some evidence that, unlike those in a vegetative state, these patients feel pain. Efforts are made to ease their suffering and to rehabilitate them. © The Economist Newspaper Limited 2009.

Keyword: Miscellaneous
Link ID: 13100 - Posted: 06.24.2010

David Cyranoski Two teams of Chinese researchers have created live mice from induced pluripotent stem (iPS) cells, answering a lingering question about the developmental potential of the cells. Since Shinya Yamanaka of Kyoto University in Japan created the first iPS cells1 in 2006, researchers have wondered whether they could generate an entire mammalian body from iPS cells, as they have from true embryonic stem cells. Experiments reported online this week in Nature 2 and in Cell Stem Cell 3 suggest that, at least for mice, the answer is yes. For the first study, animal cloners Qi Zhou of the Institute of Zoology in Beijing and Fanyi Zeng of Shanghai Jiao Tong University started by creating iPS cells the same way as Yamanaka, by using viral vectors to introduce four genes into mouse fibroblast cells. The researchers hoped that the introduced factors would 'reprogram' the cells so that they could differentiate into any type of cell in the body. To check whether the reprogramming had worked, Zhou and Zeng first carried out a standard set of tests, including analysing whether their iPS cells had the same surface markers as embryonic stem cells. Going a step further, they then created a 'tetraploid' embryo by fusing two cells of an early-stage fertilized embryo. A tetraploid embryo develops a placenta and other cells necessary for development, but not the embryonic cells that would become the body. It is, in essence, a car without a driver. © 2009 Nature Publishing Group

Keyword: Stem Cells
Link ID: 13099 - Posted: 06.24.2010

By LISA W. FODERARO NORTH ELBA, N.Y. — It was built to be impenetrable, from its “super rugged transparent polycarbonate housing” to its intricate double-tabbed lid that would keep campers’ food in and bears’ paws out. The BearVault 500 withstood the ravages of the test bears at the Folsom City Zoo in California. It has stymied mighty grizzlies weighing up to 1,000 pounds in the backcountry of Yellowstone National Park. But in one corner of the Adirondacks, campers started to notice that the BearVault, a popular canister designed to keep food and other necessities safe, was being compromised. First through circumstantial evidence, then from witness reports, it became clear that in most cases, the conqueror was a relatively tiny, extremely shy middle-aged black bear named Yellow-Yellow. Some canisters fail in the testing stage when large bears are able to rip off the lid. But wildlife officials say that Yellow-Yellow, a 125-pound bear named for two yellow ear tags that help wildlife officials keep tabs on her, has managed to systematically decipher a complex locking system that confounds even some campers. In the process, she has emerged as a near-mythical creature in the High Peaks region of the northeastern Adirondacks. “She’s quite talented,” said Jamie Hogan, owner of BearVault, based in San Diego. “I’m an engineer, and if one genius bear can do it, sooner or later there might be two genius bears. We’re trying to work on a new design that we can hopefully test on her.” Copyright 2009 The New York Times Company

Keyword: Intelligence; Evolution
Link ID: 13098 - Posted: 06.24.2010

By Michael Price When it comes to keeping cool, toucans get top billing in the animal world. New research shows that the colorful bird uses its massive beak to rapidly radiate away heat, allowing it to chill out in tropical climates or when expending a lot of energy while flying. At its most efficient, the toucan is theoretically capable of jettisoning 100% of its overall body heat loss through its bill. Birds don't sweat. Neither do elephants or rabbits. Instead, these creatures flush an uninsulated body part--such as a beak or an ear--with blood and let the heat dissipate into the air. Glenn Tattersall, an evolutionary physiologist at Brock University in Canada, wanted to find out just how much of a cooling effect the toucan's giant beak provided. He and colleagues focused on the South American toco toucan (Ramphastos toco), which has the largest bill of any bird relative to its body size. (It can represent between 30% and 50% of the creature's overall body surface area.) The team then used infrared thermal scanners to record the bill's surface temperature while the bird was exposed to air ranging from 10° to 35°C--temperatures typical of the toucan's habitat--and also while flying. By comparing the temperature of the bill with the environmental temperature, Tattersall's team was able to gauge how much heat was being lost; the larger the difference, the more heat was escaping. The bill radiated a great deal of heat at high temperatures and when the toucan flew, indicating that, like elephants and rabbits do with their ears, the toucans flush their bills with blood to cool down. © 2009 American Association for the Advancement of Science.

Keyword: Miscellaneous
Link ID: 13097 - Posted: 06.24.2010

by Ewen Callaway Apparently not content with a talk show, a monthly glossy and, well, mega-stardom, Oprah Winfrey has also penetrated the human brain. When people see her picture or hear her name, specialised "Oprah neurons" fire away, new research suggests. Other public figures shouldn't be jealous. Our heads are also flush with cells attuned to Jennifer Aniston, Halle Berry, and even Saddam Hussein. The study of epileptic patients with electrodes implanted in their brains isn't an investigation of our celebrity-obsessed culture. Rather, the research explains how distinct images and sounds of a person can trigger a general concept of them, says Rodrigo Quian Quiroga, a neuroscientist at the University of Leicester, UK. "If I see my mother, I'm not just recognising my mother," he says. "Many things are happening. I remember the last time I saw her; I remember what she looks like; I remember that I love her; I remember her cooking." Four years ago, Quian Quiroga's team made headlines when it reported the existence of neurons that fire at the sight of different pictures Jennifer Aniston, or in some cases her name spelled out on a computer screen. To determine if these cells respond to visual cues only, or to information from other senses as well, Quian Quiroga and his colleagues added sound to their tests. © Copyright Reed Business Information Ltd

Keyword: Hearing; Vision
Link ID: 13096 - Posted: 06.24.2010

by Ewen Callaway It may not be obvious from the scratch marks cats dish out, but domestic felines favour one paw over the other. More often than not, females tend to be righties, while toms are lefties, say Deborah Wells and Sarah Millsopp, psychologists at Queen's University Belfast in Northern Ireland. However, these preferences only manifest when cats perform particularly dexterous feats. That's for the same reason we can open a door with either arm, yet struggle to write legibly with our non-dominant hand. "The more complex and challenging [the task], the more likely we're going to see true handedness," Wells says. She and Millsopp tasked 42 domestic cats to ferret out a bit of tuna in a jar too small for their heads. Among 21 females, all but one favoured the right paw across dozens of trials, while 20 out of 21 males preferentially used the left. One male proved ambidextrous. Not so for two simpler activities: pawing at a toy mouse suspended in the air or dragged on ground from a string. No matter their sex, all of the cats wielded their right and left paws about equally on these less demanding tasks. Hormone levels could explain sex differences in paw choice, Wells says. Previous research has linked prenatal testosterone exposure to left-handedness. While studies of two other domestic animals, dogs and horses, revealed similar sex biases. Journal reference: Animal Behaviour (DOI: 10.1016/j.anbehav.2009.06.010) © Copyright Reed Business Information Ltd

Keyword: Laterality
Link ID: 13095 - Posted: 06.24.2010

by Ewen Callaway Legend has it that before an execution, King Charles II of England closed one eye and aimed his blind spot on the head of the condemned man. This allowed Charles' brain to decapitate the prisoner before the axe took its turn. In the video above, you can take advantage of this ability by "decapitating" author and psychologist Richard Wiseman, just as Charles II did to his victims. When Wiseman's head falls into our blind spot, our brain makes sense of the mismatch by replacing his head with the yellow background. When Wiseman raises a black bar across his body, our brain jettisons the background to avoid splitting the bar into two discontinuous halves. Blind spots occur because of design quirk in the architecture of our eyes. Cells at the back of the eye, in a layer called the retina, gather light focused through our lens from everything that's in front of us. However, where a bundle of nerves connects our eyes to our brain these light-sensitive cells cannot grow. Hence, light that hits this bundle is not sensed and a blind spot is the result. Fortunately, our brain is good at filling in gaps in our field of vision, so even with one eye shut, we rarely notice our blind spot. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 13094 - Posted: 06.24.2010

by Jennifer Barone We live in a sonic world, immersed in vibrations that stimulate microscopic hair cells deep inside our ears. This unseen energy influences our mood, our learning, even our health. We experience it as comforting music, as information-laden speech, or—all too often—as irritating noise, a by-product of our increasingly mechanized world. Despite all the ways sound affects us, we often let it slip unnoticed into the background of our lives. Hoping to understand it better, I set out to explore the mysteries of sound in the course of one day. At 6:50 a.m., my alarm clock begins the assault on my ears as the groggy gray matter between them is rudely yanked toward consciousness. My eyes shoot open, and as awareness slowly crystallizes, a single idea crowds out all others: Make the noise stop. My right hand knows just what to do and immediately puts an end to the awful blare. The formal term for the unpleasant shock that jolts me awake is acoustic startle response. Loud, sudden noises can trigger movements involving the limbs, torso, and eyelids, as well as increases in heart rate and blood pressure. This stress reaction comes in handy when noise indicates danger from, say, a wild animal or a deadly explosion. It is less useful when the enemy is a clock. The rapid movement of an object (such as the speaker in my clock) throws surrounding air molecules into a frenzy. That disturbance produces waves of high and low pressure traveling at about 760 miles per hour, which we experience as sound.

Keyword: Hearing
Link ID: 13093 - Posted: 06.24.2010

By Cassandra Willyard Anyone who has woken to a cacophony of squawks and chirps knows that birdsong, no matter how melodious, isn't always a welcome sound. Past research suggests that birds aren't keen on human din either. But a new study finds that not all birds think alike: Some species actually appear to seek out noisy environments. Among birds, noise does more than annoy. It can hinder their ability to communicate. In fact, some scientists suspect that noise pollution is at least partly responsible for the decline of bird populations. Researchers, however, have had a hard time teasing out the impacts of noise from the impacts of other noise-associated factors, such as traffic and development. To sort out whether noise alone can affect bird nesting and reproduction, community ecologist Clinton Francis of the University of Colorado, Boulder, and his colleagues spent three summers in the pinyon-juniper woodlands of northwestern New Mexico. They located nests belonging to a variety of bird species on 18 wooded plots adjacent to natural gas extraction wells; they then followed those nests throughout the summer to see whether the hatchlings fledged. The study plots were nearly identical except for one key difference: Half of the natural gas wells had compressors so loud the researchers had to shout to be heard. The other half were quiet. Contrary to the findings of previous studies, which were unable to separate the impact of noise from other confounding variables, the researchers found no difference in bird density: Noisy sites contained as many nests as quiet sites. The team did, however, see differences in species richness. © 2009 American Association for the Advancement of Science.

Keyword: Hearing
Link ID: 13092 - Posted: 06.24.2010