Most Recent Links
Follow us on Facebook or subscribe to our mailing list, to receive news updates. Learn more.
By Bret Stetka Beloved crank and Seinfeld co-creator Larry David once told an interviewer that he tolerates people like he tolerates lactose — which is to say, I'm assuming, not well. David's particular degree of grumpiness might be extreme, and perhaps embellished in the interest his shtick, but his social misgivings echo those of many in their dotage who’d rather spend time with old friends than deal with the sweat and small talk required to go out and make new ones. Humans may not be alone here. According to new research, our primate cousins also become more socially selective with age, preferring the companionship of their “friends” to monkeys that are less familiar (or maybe just a drag at parties). The findings also hint at a possible evolutionary explanation for why our social preferences change over the years. The work, conducted primarily by researchers from the German Primate Center in Göttingen, Germany, was recently published in the journal Current Biology and entailed observing the behaviors of over 100 Barbary macaque monkeys, an out-going, some might say "screechy," species hailing from North Africa. To get a sense of how interest in non-social vs social stimulation changes over the course of their lifetimes, monkeys of varying ages were observed in the presence of both inanimate objects and other monkeys. They were first presented with three novel objects: animal toys, a see-through cube filled with glitter in a viscous liquid, and a tube baited with food. Those that had reached early adulthood were not interested in the objects without a reward. The younger ones were intrigued by all three. © 2016 Scientific American
Keyword: Evolution; Emotions
Link ID: 22396 - Posted: 07.05.2016
Laura Sanders Feeling good may help the body fight germs, experiments on mice suggest. When activated, nerve cells that help signal reward also boost the mice’s immune systems, scientists report July 4 in Nature Medicine. The study links positive feelings to a supercharged immune system, results that may partially explain the placebo effect. Scientists artificially dialed up the activity of nerve cells in the ventral tegmental area — a part of the brain thought to help dole out rewarding feelings. This activation had a big effect on the mice’s immune systems, Tamar Ben-Shaanan of Technion-Israel Institute of Technology in Haifa and colleagues found. A day after the nerve cells in the ventral tegmental area were activated, mice were infected with E. coli bacteria. Later tests revealed that mice with artificially activated nerve cells had less E. coli in their bodies than mice without the nerve cell activation. Certain immune cells seemed to be ramped up, too. Monocytes and macrophages were more powerful E. coli killers after the nerve cell activation. If a similar effect is found in people, the results may offer a biological explanation for how positive thinking can influence health. |© Society for Science & the Public 2000 - 2016
Keyword: Neuroimmunology; Emotions
Link ID: 22395 - Posted: 07.05.2016
Mo Costandi There’s much more to visual perception than meets the eye. What we see is not merely a matter of patterns of light falling on the retina, but rather is heavily influenced by so-called ‘top-down’ brain mechanisms, which can alter the visual information, and other types of sensory information, that enters the brain before it even reaches our conscious awareness. A striking example of this is a phenomenon called inattentional blindness, whereby narrowly focusing one’s attention on one visual stimulus makes us oblivious to other stimuli, even though they otherwise may be glaringly obvious, as demonstrated by the infamous ‘Invisible Gorilla’ study. Now researchers say they have discovered another extreme form of blindness, in which people fail to notice an unexpected image, even when shown by itself and staring them in the face. Marjan Persuh and Robert Melara of the City University of New York designed two experiments to investigate whether people’s prior expectations could block their awareness of meaningful and important visual stimuli. In the first, they recruited 20 student volunteers and asked them to perform a visual discrimination task. They were shown a series of images, consisting of successive pairs of faces, each of which were presented for half a second on a computer screen, and asked to indicate whether each pair showed faces of people of the same or different sex. Towards the end of each session, the participants were presented with a simple shape, which flashed onto the screen for one tenth of a second. They were then asked if they had seen anything new and, after replying, were told that a shape had indeed appeared, and asked to select the correct one from a display of four. This shape recognition task was then repeated in one final control trial. © 2016 Guardian News and Media Limited
Keyword: Attention
Link ID: 22394 - Posted: 07.04.2016
Jackie Goldstein Mental illness has been part of human society throughout recorded history, but how we care for people with mental disorders has changed radically, and not always for the better. In Colonial days, settlers lived in sparsely populated rural communities where sanctuary and community support enabled the tradition of family care brought from England. "Distracted persons" were acknowledged, but erratic behavior wasn't associated with disease. Records indicate unusual tolerance of bizarre behavior. When 18th century Pastor Joseph Moody of York, Maine, unable to face crowds, delivered sermons with a handkerchief covering his face, his behavior was tolerated for three years before he was relieved of his duties. As urban areas grew in size and number, a transient poor population with no access to family support led to almshouses, the first form of institutionalization, inspired by 18th century reforms in Europe. A Philadelphia Quaker who had visited an English retreat brought the idea to this country and in 1817 founded the Friends Asylum, a self-sufficient farm that offered a stress-free environment known as "moral treatment." Other private asylums followed, but they soon became overcrowded. By the late 19th century, this was addressed with larger state hospitals, which soon became overcrowded as well. People with mental disorders are more likely to be stigmatized owing to fear and misunderstanding when they aren't part of the community. And stigmatization can discourage those with a mental disorder from seeking or complying with treatment. © 2016 npr
Keyword: Schizophrenia
Link ID: 22393 - Posted: 07.04.2016
By Anthea Rowan The neurologist does not cushion his words. He tells us how it is: “She won’t read again.” I am standing behind my mother. I feel her stiffen. We do not talk of this revelation for days — and when we do, we do it in the garden of the rehab facility where she is recovering from a stroke. The stroke has scattered her memory, but she has not forgotten she will apparently not read again. I was shocked by what the doctor said, she confides. Me, too. Do you believe him? she asks. No — I am emphatic, for her and for me — I don’t. Mum smiles: “Me neither.” The damage wreaked by Mum’s stroke leaked across her brain, set up roadblocks so that the cerebral circuit board fizzes and pops uselessly, with messages no longer neatly passing from “A” to “B.” I tell the neuro: “I thought they’d learn to go via ‘D’ or ‘W.’ Isn’t that what’s supposed to happen — messages reroute?” “Unlikely,” he responds. “In your mother’s case.” Alexia — the loss of the ability to read — is common after strokes, especially, as in my mother’s case, when damage is wrought in the brain’s occipital lobe, which processes visual information. Pure alexia, which is Mum’s diagnosis, is much more rare: She can still write and touch-type, but bizarrely, she cannot read.
Keyword: Language; Stroke
Link ID: 22392 - Posted: 07.04.2016
Carl Zimmer Our genes are not just naked stretches of DNA. They’re coiled into intricate three-dimensional tangles, their lengths decorated with tiny molecular “caps.” These so-called epigenetic marks are crucial to the workings of the genome: They can silence some genes and activate others. Epigenetic marks are crucial for our development. Among other functions, they direct a single egg to produce the many cell types, including blood and brain cells, in our bodies. But some high-profile studies have recently suggested something more: that the environment can change your epigenetic marks later in life, and that those changes can have long-lasting effects on health. In May, Duke University researchers claimed that epigenetics could explain why people who grow up poor are at greater risk of depression as adults. Even more provocative studies suggest that when epigenetic marks change, people can pass them to their children, reprogramming their genes. But criticism of these studies has been growing. Some researchers argue that the experiments have been weakly designed: Very often, they say, it’s impossible for scientists to confirm that epigenetics is responsible for the effects they see. Three prominent researchers recently outlined their skepticism in detail in the journal PLoS Genetics. The field, they say, needs an overhaul. “We need to get drunk, go home, have a bit of a cry, and then do something about it tomorrow,” said John M. Greally, one of the authors and an epigenetics expert at the Albert Einstein College of Medicine in New York. © 2016 The New York Times Company
Keyword: Epigenetics; Genes & Behavior
Link ID: 22391 - Posted: 07.02.2016
By Jessica Hamzelou Imagine if each of the words in this article had their own taste, or the music you’re listening to played out as visual scene in your mind. For synaesthetes – a small proportion of people whose senses intertwine – this is the stuff of the every day. “Most people describe it as a gift,” says Jamie Ward, a neuroscientist at the University of Sussex in the UK. Now, he and his colleagues have found a new form of synaesthesia – one that moves beyond written language to sign language. It is the first time the phenomenon has been observed. “People with synaesthesia experience the ordinary world in extraordinary ways,” says Ward. In theory, any two senses can overlap. Some synaesthetes connect textures with words, while others can taste them. More commonly, written letters seem to have corresponding colours. An individual synaesthete may always associate the letter A with the colour pink, for instance. This type of synaesthesia has been found across many written languages, prompting Ward’s team to wonder if it can also apply to sign language. They recruited 50 volunteers with the type of synaesthesia that means they experience colours with letters, around half of whom were fluent in sign language too. All the participants watched a video of sign language and were asked if it triggered any colours. © Copyright Reed Business Information Ltd.
Keyword: Vision
Link ID: 22390 - Posted: 07.02.2016
By JAN HOFFMAN About 1.4 million adults in the United States identify as transgender, double a widely used previous estimate, according to an analysis based on new federal and state data. As the national debate escalates over accommodations for transgender people, the new figure, though still just 0.6 percent of the adult population, is likely to raise questions about the sufficiency of services to support a population that may be larger than many policy makers assumed. “There’s a saying: ‘You don’t count in policy circles until someone counts you,’” said Gary J. Gates, a demographer and former research director of the group that did the analysis, the Williams Institute at the U.C.L.A. School of Law, which focuses on law and policy issues related to sexual orientation and gender identity. The Williams Institute is the research group that produced a widely accepted estimate five years ago. Its new number was drawn from a much larger federal database than it used to reach the earlier projection of 0.3 percent, or 700,000 people. Noting that younger adults ages 18 to 24 were more likely than older ones to say they were transgender, researchers said that the new estimates reflected in part a growing awareness of transgender identity. The analysis may also reflect the limits of self-reporting in obtaining definitive data. In some states seen as more accepting, more adults identified themselves as transgender. In some states perceived as more resistant, fewer adults did so, even though the surveys were anonymous. The percentage of adults identifying as transgender by state ranged from lows of 0.30 percent in North Dakota, 0.31 percent in Iowa and 0.32 percent in Wyoming to highs of 0.78 percent in Hawaii, 0.76 percent in California and 0.75 percent in Georgia. In some states the results at first glance seemed surprising. In New York, for example, the percentage was 0.51; in Texas it was 0.66. © 2016 The New York Times Company
Keyword: Sexual Behavior
Link ID: 22389 - Posted: 07.02.2016
by Sarah Zielinski Among people, a man stepping aside to let a woman pass through a door first is seen as a gentlemanly — if a bit old-fashioned — act. Among banana fiddler crabs, though, this behavior is a trap — one that lets a male crab coerce a female into a mating she may not have preferred. To catch the attention of a female and lure her into his burrow, a male banana fiddler crab stands outside the entrance to his cave and waves the larger of his two claws. A female will look him over and consider his size, the color of his claw and how he’s waving it. If she likes what she sees, she’ll approach him. She might decide to enter his burrow and check it out, and once inside, she might stick around for mating if she thinks that the burrow has the right conditions for rearing her embryos. When a female approaches a male and his burrow, most males enter first, letting their potential mate follow him down. But many male crabs take another approach, stepping aside and following her into the lair — letting a male trap the female inside and mate with her, researchers report June 15 in PLOS ONE. Christina Painting of the Australian National University in Canberra and colleagues observed banana fiddler crabs in Darwin, Australia, during two mating seasons, watching what happened as males waved their claws and females made their choice. When a female was interested in a male, the guys entered the burrow first 32 percent of the time. While females were more likely to enter a burrow if a male entered first (71 percent versus only 41 percent when the guy stepped aside), the trapping strategy was more successful in getting a mating out of the meeting. When the male followed the female in, 79 percent of females stuck around the mate. But waiting for her to follow resulted in a pairing only 54 percent of the time. © Society for Science & the Public 2000 - 2016
Keyword: Sexual Behavior; Evolution
Link ID: 22388 - Posted: 07.02.2016
Laurel Hamers Even Amelia Earhart couldn’t compete with the great frigate bird. She flew nonstop across the United States for 19 hours in 1932; the frigate bird can stay aloft up to two months without landing, a new study finds. The seabird saves energy on transoceanic treks by capitalizing on the large-scale movement patterns of the atmosphere, researchers report in the July 1 Science. By hitching a ride on favorable winds, the bird can spend more time soaring and less time flapping its wings. “Frigate birds are really an anomaly,” says Scott Shaffer, an ecologist at San Jose State University in California who wasn’t involved in the study. The large seabird spends much of its life over the open ocean. Both juvenile and adult birds undertake nonstop flights lasting weeks or months, the scientists found. Frigate birds can’t land in the water to catch a meal or take a break because their feathers aren’t waterproof, so scientists weren’t sure how the birds made such extreme journeys. Researchers attached tiny accelerometers, GPS trackers and heart rate monitors to great frigate birds flying from a tiny island near Madagascar. By pooling data collected over several years, the team re-created what the birds were doing minute-by-minute over long flights — everything from how often the birds flapped their wings to when they dived for food. © Society for Science & the Public 2000 - 2016.
Keyword: Sleep; Animal Migration
Link ID: 22387 - Posted: 07.01.2016
By Tara Parker-Pope About one in eight women take an antidepressant at some time during pregnancy, reports Roni Rabin in today’s Science Times. But is it safe? Some new research shows that antidepressant use during pregnancy may be linked to certain problems in newborns. A new review of the medical literature concludes that treatment decisions for depression during pregnancy must be made on a case-by-case basis. “There’s not a one-size-fits-all answer,” said Dr. Kimberly Yonkers, a professor of psychiatry and obstetrics and gynecology at Yale School of Medicine who was the report’s lead author, and who acknowledged receiving research support from antidepressant manufacturers. “You can’t say, ‘Stop medication for all women because it’s harmful,’ and you can’t put all women on medication either.” To learn more, read the full story, “Depression Is a Dilemma for Women in Pregnancy,” and then please join the discussion below. Did you experience depression during pregnancy? Did you take medication to treat it? © 2016 The New York Times Company
Keyword: Depression; Development of the Brain
Link ID: 22386 - Posted: 07.01.2016
Angus Chen At the center of Geel, a charming Belgian town less than an hour's drive from of Antwerp, is a church dedicated to Dymphna, a saint believed to have the power to cure mental disorders. It's a medieval church with stone arches, spires and a half-built bell tower, and it has inspired an unusual centuries-old practice: For over 700 years, residents of Geel have been accepting people with mental disorders, often very severe mental disorders, into their homes and caring for them. It isn't meant to be a treatment or therapy. The people are not called patients, but guests or boarders. They go to Geel and join households to share a life with people who can watch over them. Today, there are about 250 boarders in Geel. One of them is a Flemish man named Luc Ennekans. He's slim and has green eyes, and he's 51 years old. NPR's Lulu Miller went to Geel and met him and his host family there and reported this story for Invisibilia. Like all of the guests in the town today, Ennekans first went to a public psychiatric hospital in Geel that manages the boarder program. Ennekans saw medical professionals and received treatment and an evaluation. Then he was paired with a household. His hosts, Toni Smit and Arthur Shouten, say that living with Ennekans was rough at the start. Ennekans became deeply attached to Smit. "If it were up to Luc, he would be hugging and kissing me all day," Smit says. He showered her with such affection, bringing her flowers, little kisses, linking arms with her on walks, that it began to interfere with Smit and Shouten's marriage. "You couldn't even give each other a hug or Luc is standing behind us," Shouten says. Wrinkles like this are common, according to the couple. They've had six boarders over the years, each with a unique set of challenges. © 2016 npr
Keyword: Schizophrenia; Depression
Link ID: 22385 - Posted: 07.01.2016
By Amina Zafar, CBC News The Zika virus can cause devastating brain defects in newborns with microcephaly, but also in babies with normal-sized heads and those born to women infected late in pregnancy, Brazilian doctors say. In Wednesday's issue of the journal The Lancet, researchers said that of 602 babies born in Brazil with definite or probable Zika cases one in five had head circumferences in the normal range. Dr. Cesar Victora of the Federal University of Pelotas in Rio Grande do Sul, Brazil, and his team say the current focus on screening for microcephaly or small head circumference alone is too narrow. "We should not equate Zika congenital infection with microcephaly," Victora said in an interview from Washington. "We could well have many babies with normal head size who are affected. We will need to think about other exams to screen these babies, such as improving the diagnostic test we have for Zika and also possibly in areas that are undergoing an epidemic, doing ultrasound of the brains of these babies as soon as they are born." The epidemic in the worst-hit northeastern regions of the country peaked in November 2015. While the current season is cooler and mosquitoes aren't reproducing in Brazil, public health authorities continue to advise pregnant women to avoid travel to countries with Zika outbreaks. Countries in South Asia, the Western Pacific Islands, and South and Central America also have outbreaks. ©2016 CBC/Radio-Canada.
Keyword: Development of the Brain
Link ID: 22384 - Posted: 07.01.2016
By Maya Smith Bonobos (pictured) are known as the peaceful ape. They’re less aggressive than their chimpanzee cousins, and when they have disagreements they’re more likely to make love, not war. Now, a new study reveals one way females keep the peace. In most primate societies, female genitals swell to advertise that they’re ready to mate, leading to fighting among males as they jostle for a partner. But in bonobos, the swellings only indicate fertility half the time, according to a study in the wild published this week in BMC Evolutionary Biology. The findings confirm what scientists have observed in captivity. The researchers behind the new study hypothesize females may have evolved the behavior to gain the upper hand in mating. Because males cannot look to sexual swellings as a reliable indicator of fertility, the females are free to choose their mates. And that helps everyone get along. © 2016 American Association for the Advancement of Science.
Keyword: Sexual Behavior; Aggression
Link ID: 22383 - Posted: 07.01.2016
by Bethany Brookshire There’s an osprey nest just outside Jeffrey Brodeur’s office at the Woods Hole Oceanographic Institution in Massachusetts. “I literally turn to my left and they’re right there,” says Brodeur, the organization’s communications and outreach specialist. WHOI started live-streaming the osprey nest in 2005. For the first few years, few people really noticed. All that changed in 2014. An osprey pair had taken up residence and produced two chicks. But the mother began to attack her own offspring. Brodeur began getting e-mails complaining about “momzilla.” And that was just the beginning. “We became this trainwreck of an osprey nest,” he says. In the summer of 2015, the osprey family tried again. This time, they suffered food shortages. The camera received an avalanche of attention, complaints and e-mails protesting the institute’s lack of intervention. One scolded, “it is absolutely disgusting that you will not take those chicks away from that demented witch of a parent!!!!! Instead you let them be constantly abused and go without [sic] food. Yes this is nature but you have a choice to help or not. This is totally unacceptable. She should be done away with so not to abuse again.” By mid-2015, Brodeur began to receive threats. “People were saying ‘we’re gonna come help them if you don’t,’” he recalls. The osprey cam was turned off, and remains off to this day. Brodeur says he’s always wondered why people had such strong feelings about a bird’s parenting skills. Why do people spend so much time and emotion attempting to apply their own moral sense to an animal’s actions? The answer lies in the human capacity for empathy — one of the qualities that helps us along as a social species. © Society for Science & the Public 2000 - 2016.
Keyword: Animal Rights; Emotions
Link ID: 22382 - Posted: 06.30.2016
By Aviva Rutkin MONKEYS controlling a robotic arm with their thoughts. Chicks born with a bit of quail brain spliced in. Rats with their brains synced to create a mind-meld computer. For two days in June, some of neuroscience’s most extraordinary feats were debated over coffee and vegetarian food at the Institute for Research in Cognitive Science in Philadelphia. The idea wasn’t to celebrate these accomplishments but to examine them. Martha Farah, a cognitive neuroscientist at the University of Pennsylvania, assembled a group of scientists, philosophers and policy-makers to discuss the moral implications for the animals involved. “An animal would go from being a thing to a person, with all the moral and legal status that implies“ “Neuroscience is remodelling – in sometimes shocking ways – the conventional boundaries between creatures versus organs versus tissue, between machines versus animals, between one species versus blended species,” Farah told New Scientist. “We thought, let’s look at the ways in which advances in animal neuroscience might raise new ethical issues that haven’t been encountered before, or that might have changed enough that they need revisiting.” It’s a timely question. Animal welfare has been hotly debated in some corners for years, but a handful of recent cases have brought the issue to the fore. Last year, under pressure from activists and Congress, the US National Institutes of Health shut down its chimp research programme, and sent the animals to sanctuaries. © Copyright Reed Business Information Ltd.
Keyword: Animal Rights
Link ID: 22381 - Posted: 06.30.2016
By Gary Stix Bullies often like being bullies—and an entire line of research links aggressive behaviors to brain areas tied to sensations of reward—sites deep below the organ’s surface with names like the ventromedial hypothalamus and the extended amygdala. One lingering puzzle is what precedes the aggressive act. What makes a person—or, in this case, a mouse—lash out? A new study, published June 29 in Nature, shows that the thought of being the aggressor simply feels good to certain animals. I had a fascinating talk this week with Scott Russo from the Icahn School of Medicine at Mount Sinai, the paper’s senior author, who described the significance of these findings. What did your study find? We discovered a brain circuit—connecting the basal forebrain and lateral habenula—that appears to control the motivation of a male mouse to be aggressive and subordinate another male mouse. The significance of these findings is that the circuit seems to be telling an animal that subordinating, or “bullying,” another animal is a rewarding behavior. To test this, we adapted a conditioned place preference protocol—often used to measure the rewarding properties of addictive drugs, whereby mice were allowed to attack an intruder mouse within one of two environmental contexts: When asked which of the two environmental contexts they preferred, aggressive mice chose the environment in which they were allowed to attack the intruder mouse over the environment in which they had no access to the intruder mouse. Interestingly, the basal forebrain and lateral habenula have been previously shown to support conditioned place preference to drugs of abuse, such as nicotine and cocaine, suggesting that similar neural processes mediate rewarding aspects of aggression and addictive substances. © 2016 Scientific American
Keyword: Aggression
Link ID: 22380 - Posted: 06.30.2016
When you walk into a room, your eyes process your surroundings immediately: refrigerator, sink, table, chairs. "This is the kitchen," you realize. Your brain has taken data and come to a clear conclusion about the world around you, in an instant. But how does this actually happen? Elissa Aminoff, a research scientist in the Department of Psychology and the Center for the Neural Basis of Cognition at Carnegie Mellon University, shares her insights on what computer modeling can tell us about human vision and memory. What do you do? What interests me is how the brain and the mind understand our visual environment. The visual world is really rich with information, and it’s extremely complex. So we have to find ways to break visual data down. What specific parts of our [visual] world is the brain using to give us what we see? In order to answer that question, we’re collaborating with computer scientists and using computer vision algorithms. The goal is to compare these digital methods with the brain. Perhaps they can help us find out what types of data the brain is working with. Does that mean that our brains function like a computer? That’s something you hear a lot about these days. No, I wouldn’t say that. It’s that computers are giving us the closest thing that we have right now to an analogous mechanism. The brain is really, really complex. It deals with massive amounts of data. We need help in organizing these data and computers can do that. Right now, there are algorithms that can identify an object as a phone or as a mug, just like the brain. But are they doing the same thing? Probably not. © 2016 Scientific American,
Keyword: Vision
Link ID: 22379 - Posted: 06.30.2016
By Aviva Rutkin Machine minds are often described as black boxes, their decision-making processes all but inscrutable. But in the case of machine intelligence, researchers are cracking that black box open and peering inside. What they find is that humans and machines don’t pay attention to the same things when they look at pictures – not at all. Researchers at Facebook and Virginia Tech in Blacksburg got humans and machines to look at pictures and answer simple questions – a task that neural-network-based artificial intelligence can handle. But the researchers weren’t interested in the answers. They wanted to map human and AI attention, in order to shed a little light on the differences between us and them. “These attention maps are something we can measure in both humans and machines, which is pretty rare,” says Lawrence Zitnick at Facebook AI Research. Comparing the two could provide insight “into whether computers are looking in the right place”. First, Zitnick and his colleagues asked human workers on Amazon Mechanical Turk to answer simple questions about a set of pictures, such as “What is the man doing?” or “What number of cats are lying on the bed?” Each picture was blurred, and the worker would have to click around to sharpen it. A map of those clicks served as a guide to what part of the picture they were paying attention to. © Copyright Reed Business Information Ltd.
Keyword: Vision
Link ID: 22378 - Posted: 06.30.2016
By Patrick Monahan Birds are perhaps best known for their bright colors, aerial prowess, and melodic songs. But research presented in Austin last week at the Evolution Conference shows that bacteria have granted some birds another important attribute: stink. Having long taken a back seat to sight and sound, scent is becoming more and more recognized as an important sense for songbirds, and dark-eyed juncos (Junco hyemalis, pictured) are no stranger to it. When these common birds clean their feathers—or preen—they spread pungent oil from their “preen glands” all over their bodies. The act is important for enticing mates: Three of the gland’s smelly chemicals are found in very different quantities in the two sexes, and males with a more masculine musk end up with more offspring. Females with a more feminine scent profile are more successful, too. But juncos likely aren’t making their perfume alone: Lots of those preen gland chemicals are naturally made by bacteria. And new work is making the bird-bacteria link even more firm. When researchers inject antibiotics into the juncos’ preen glands, the concentrations of three smelly molecules tend to decrease—the same three molecules that juncos find sexy in the right proportions, Danielle Whittaker of Michigan State University in East Lansing told attendees. So it seems like juncos may actually be picking mates based on their bacterial—rather than self-produced—body odor, a first for birds. © 2016 American Association for the Advancement of Science.
Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 22377 - Posted: 06.30.2016