Monday, December 30, 2013

Professor admits faking AIDS vaccine to get $19M in grants

By Andy Soltis
An Iowa State University professor resigned after admitting he falsely claimed rabbit blood could be turned into a vaccine for the AIDS virus.
Dr. Dong-Pyou Han spiked a clinical test sample with healthy human blood to make it appear that the rabbit serum produced disease-fighting antibodies, officials said.
The bogus findings helped Han’s team obtain $19 million in research grants from the National Institutes of Health, said James Bradac, who oversees the institutes’ AIDS research.
The remarkable findings were reported in scientific journals but raised suspicions when other researchers could not duplicate Han’s results.
The NIH uncovered the scam when it checked the rabbit serum at a lab and found the human antibodies.
Han resigned from his university post as an assistant professor of biomedical studies  in October. His case came to light this week when it was reported in the Federal Register.
Han agreed last month not to seek government contracts for three years, the register said.

Sunday, December 29, 2013

Photo Captures Apparent Encounter With Shark at Manhattan Beach

  • June Emerson made a startling discovery while reviewing the photos she took during a visit to Manhattan Beach on Friday.
    Among the images is one that shows her 12-year-old son Quinn and his friend, both with their surfboards, in front of a breaking wave – and what appears to be a rather sizable shark.
    Twelve-year-old Quinn Emerson, right, and a friend apparently had a close encounter with a shark at Manhattan Beach on Friday, Dec. 27, 2013. (Credit: June Emerson)

    “It was quite a shock to see” the photo, June Emerson said.
    “Many local surfers and lifeguards have seen this and believe it to be a shark,” she said. “Of course, I told my kids it was dolphin, as we live at the beach and are in the waters here almost daily.”
    Sightings of great white sharks are not uncommon near Manhattan Beach.

    The starfish are dying, and no one knows why

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    Something is killing starfish up and down the West Coast and no one knows what.
    A mysterious illness that first appeared in June in Washington state has now spread from Sitka, Alaska, to San Diego. Starfish first waste away and then "turn into goo," divers say. Whatever is causing it can spread with astonishing speed — a healthy group of starfish can die in just 24 hours.
    "It's widespread, it's very virulent and it's unlike anything we've seen in the past," said Pete Raimondi, a marine ecologist at the University of California-Santa Cruz who is one of the lead researchers in an international effort to track the outbreak.
    The ailment seems to hit starfish the hardest, with smaller numbers of sea urchins and sea cucumbers reported falling to it. No one knows what percentage of the West Coast's starfish are affected but in some areas they've been wiped out.
    So far at least 12 different starfish species are known to be at risk, Raimondi said.
    Marine biologists call starfish "sea stars" because they are not actually fish, but invertebrates. They've dubbed the ailment "sea star wasting syndrome."
    The first case was reported in a tide pool in Washington state's Olympic NationalPark in June. Within weeks sea stars in the Vancouver Aquarium in British Columbia were dying, and sea stars near Sitka, Alaska, also began to fall ill.
    The animals first "look a little bit odd," said Mike Murray, director of veterinary services at the Monterey Bay Aquarium in Monterey, Calif. "Their arms may be twisted or weirdly positioned."
    They then develop what look like tiny wounds on their surface and bits of whitish discoloration. Within days and sometimes hours, the animal begins to waste away and fall apart. "It's almost like they're melting," he says. "They turn into slime or goo, they just kind of disintegrate."
    Scientists are asking recreational divers to report outbreaks. Don Noviello is a member of the Kelp Krawlers Dive Club in Olympia Wash. He and a dive partner saw their first infected sea stars on Dec. 21.
    "It's like they become zombies of the sea," Noviello said. "I saw a leg walking away by itself," he said.
    Scientists are scrambling to find the cause. The National Science Foundation gave rapid response research grants over the summer so marine biologists could begin intensively studying the problem. Groups far and wide are involved, including the National Wildlife Center in Madison, Wis., Cornell University in Ithaca, N.Y., and various universities in Canada.
    Teams are now going up and down the West Coast looking for outbreaks so they can develop an accurate map of affected areas. The list is ever increasing. "We had our first report in Santa Barbara on Dec. 7," Raimondi said. "Last week, they found five affected areas there."
    Researchers believe the sea stars' actual disintegration and death is caused by bacterial infection, but they have no idea what's suddenly making them susceptible.
    Raimondi put it this way: "Suppose someone's walking down the street and they get stabbed in the arm and develop an infection and die. So the infection killed them, but the real question is this: Who stabbed them in the first place?"
    There have been previous, small scale sea star die-offs. While they looked similar, "there are only certain ways starfish can look when they die. A melting starfish is going to look like a melting starfish," Murray said.
    The cause could be a toxins, a virus, bacteria, manmade chemicals, ocean acidification, wastewater discharge or warming oceans. "We're not ruling anything out," Raimondi said.
    The fact that the ailment is so widespread is what's most troubling, said Benjamin Miner, a professor of marine biology at Western Washington University in Bellingham, Wash. "Every time you come up with what seems like a reasonable hypothesis, it's challenged because other affected places don't match."
    Whatever is killing the sea stars is highly lethal. "We've had populations go locally extinct overnight. Literally. Some species go from completely fine to a mush ball in 24 hours," said Miner, who's organizing the mapping project.
    Starfish may seem fairly unimportant, but they're actually a keystone species in many marine environments. Most live near the shore, but some inhabit the bottom of deep seas. Few things eat them, but they are a top predator, eating mussels, barnacles and sea snails.
    "The niche they fill is vital. If they die off, the ecological communities they live in could change fundamentally," Raimondi said.
    Sea stars aren't eaten by humans, and there is no danger to people who might come into contact with them, Murray said. However, "melting sea stars, or not, any time you handle wildlife, you want to wash your hands."
    Asked for a bright spot, Raimondi could only think of one: "Sea stars don't feel pain," so death by dissolving doesn't hurt them.

    Wednesday, December 25, 2013

    Killer whales dazzle in hourlong show off L.A.; ‘Like SeaWorld without the tanks’

    The Big Blue An Outdoor // Nature Blog

    Wild orcas leap and and splash in close proximity of awed researchers during the mammals' third consecutive holiday season visit to Southern California

    Photo showing young orca named Comet is courtesy of ©Eric Martin
    Killer whales are at the center of a broiling SeaWorld controversy, thanks to “Blackfish the Movie,” which has shed light on how the iconic mammals are treated in captivity.
    Many are boycotting SeaWorld parks. Animal rights advocates have arranged on-site protests, and several entertainers have canceled shows in opposition to SeaWorld’s captive killer whale programs.
    Photo showing spyhopping orcas is courtesy of ©Alisa Schulman-Janiger. She also provided the following four images for this story
    SeaWorld’s shows continue, however, the park insisting that its orcas are ambassadors who foster appreciation of the ocean and its critters.
    But this week off Los Angeles, four wild killer whales proved emphatically that their most spectacular shows are those performed willingly in the wild, and that fishy treats are not required for them to leap and splash.
    Alisa Schulman-Janiger, a killer whale researcher, and Eric Martin, a marine biologist, on Monday afternoon were witness to a show both said they will never forget.
    Chorus-line greeting
    “It was like SeaWorld without the tanks,” joked Martin, co-director of the Roundhouse Marine Studies Lab and Aquarium at the end of Manhattan Beach Pier.
    The encounter began nine miles west of Redondo Beach, with what Schulman-Janiger described as “a chorus line greeting,” and ended an hour later a bit farther to the north.
    The killer whales breached and spyhopped, surfed wakes created by the moving boat, and played beneath the vessel.
    They even killed a smaller mammal–most likely a common dolphin–and celebrated with more acrobatics.
    “They often do that after a kill,” Schulman-Janiger said, adding that this marks the third consecutive year these particular killer whales have appeared off Los Angeles during the holiday season. (Their home turf seems to be Monterey Bay in Central California.)
    The orcas are family members that include the matriarch cataloged by Schulman-Janiger as CA51, a 15-year-old male (CA51B), a 10-year-old male (CA51C), and a 3-year-old female (CA51D), who is named Comet because of her unusual eye patches.
    They’re part of a group of transient killer whales that are known to be boat friendly (CA51C  was nicknamed “Bumper” by Schulman-Janiger last December after it gently belly-bumped Martin’s boat during a lengthy encounter).This group, more than any other, has widened its range to include Southern California, presumably to prey on common dolphins.
    It used to include CA51′s 21-year-old daughter, who has formed a separate sub-pod with her two offspring.
    Monday’s sighting was the fifth in four weeks of the CA51 group off the Los Angeles/Long Beach area. The sighting was first made by volunteers with the ACS-LA Gray Whale Census and Behavior Project at Point Vicente on the Palos Verdes Peninsula.
    That inspired Schulman-Janiger and Martin to embark on a search aboard his 18-foot boat.
    They spotted a tall, black dorsal fin at 3:07 p.m. and 13 minutes later were surrounded by orcas.
    “They approached and came right at us and stopped all together,” Schulman-Janiger said. “It was like a chorus-line greeting. They swam under and around our boat and poked their faces out of the water. They did this five or six times.”
    When Martin would run his boat the killer whales would surf in its wake, the largest male a mere inches from the transom. When the boat stopped, the mammals surrounded the boat and resumed playing around and beneath the vessel, poking their heads out of the water for a closer look at their visitors.
    Said Martin: “They were making eye contact with us, not just the boat. They were looking into our eyes, the way a human does. I don’t see how it can get any better.”
    Perhaps this act could be labeled, “Blackfish, Wild and Free.”
    –Find Pete Thomas on Facebook

    Sunday, December 22, 2013

    Spike in Harm to Liver Is Tied to Dietary Aids

    Michael Stravato for The New York Times
    Christopher Herrera and his mother, Lordes Gonzalez, at home in Katy, Tex. A green tea extract nearly cost Christopher his liver.

    When Christopher Herrera, 17, walked into the emergency room at Texas Children’s Hospital one morning last year, his chest, face and eyes were bright yellow — “almost highlighter yellow,” recalled Dr. Shreena S. Patel, the pediatric resident who treated him.
    Chester Higgins Jr./The New York Times
    About 55,000 dietary supplements, largely unregulated, are sold in the United States.
    Christopher, a high school student from Katy, Tex., suffered severe liver damage after using a concentrated green tea extract he bought at a nutrition store as a “fat burning” supplement. The damage was so extensive that he was put on the waiting list for a liver transplant.
    “It was terrifying,” he said in an interview. “They kept telling me they had the best surgeons, and they were trying to comfort me. But they were saying that I needed a new liver and that my body could reject it.”
    New data suggests that his is not an isolated case. Dietary supplements account for nearly 20 percent of drug-related liver injuries that turn up in hospitals, up from 7 percent a decade ago, according to an analysis by a national network of liver specialists. The research included only the most severe cases of liver damage referred to a representative group of hospitals around the country, and the investigators said they were undercounting the actual number of cases.
    While many patients recover once they stop taking the supplements and receive treatment, a few require liver transplants or die because of liver failure. Naïve teenagers are not the only consumers at risk, the researchers said. Many are middle-aged women who turn to dietary supplements that promise to burn fat or speed up weight loss.
    “It’s really the Wild West,” said Dr. Herbert L. Bonkovsky, the director of the liver, digestive and metabolic disorders laboratory at Carolinas HealthCare System in Charlotte, N.C. “When people buy these dietary supplements, it’s anybody’s guess as to what they’re getting.”
    Though doctors were able to save his liver, Christopher can no longer play sports, spend much time outdoors or exert himself, lest he strain the organ. He must make monthly visits to a doctor to assess his liver function.
    Americans spend an estimated $32 billion on dietary supplements every year, attracted by unproven claims that various pills and powders will help them lose weight, build muscle and fight off everything from colds to chronic illnesses. About half of Americans use dietary supplements, and most of them take more than one product at a time.
    Dr. Victor Navarro, the chairman of the hepatology division at Einstein Healthcare Network in Philadelphia, said that while liver injuries linked to supplements were alarming, he believed that a majority of supplements were generally safe. Most of the liver injuries tracked by a network of medical officials are caused by prescription drugs used to treat things like cancer, diabetes and heart disease, he said.
    But the supplement business is largely unregulated. In recent years, critics of the industry have called for measures that would force companies to prove that their products are safe, genuine and made in accordance with strict manufacturing standards before they reach the market.
    But a federal law enacted in 1994, the Dietary Supplement Health and Education Act, prevents the Food and Drug Administration from approving or evaluating most supplements before they are sold. Usually the agency must wait until consumers are harmed before officials can remove products from stores. Because the supplement industry operates on the honor system, studies show, the market has been flooded with products that are adulterated, mislabeled or packaged in dosages that have not been studied for safety.
    The new research found that many of the products implicated in liver injuries were bodybuilding supplements spiked with unlisted steroids, and herbal pills and powders promising to increase energy and help consumers lose weight.
    “There unfortunately are criminals that feel it’s a business opportunity to spike some products and sell them as dietary supplements,” said Duffy MacKay, a spokesman for the Council for Responsible Nutrition, a supplement industry trade group. “It’s the fringe of the industry, but as you can see, it is affecting some consumers.” More popular supplements like vitamins, minerals, probiotics and fish oil had not been linked to “patterns of adverse effects,” he said.
    The F.D.A. estimates that 70 percent of dietary supplement companies are not following basic quality control standards that would help prevent adulteration of their products. Of about 55,000 supplements that are sold in the United States, only 170 — about 0.3 percent — have been studied closely enough to determine their common side effects, said Dr. Paul A. Offit, the chief of infectious diseases at the Children’s Hospital of Philadelphia and an expert on dietary supplements.
    “When a product is regulated, you know the benefits and the risks and you can make an informed decision about whether or not to take it,” he said. “With supplements, you don’t have efficacy data and you don’t have safety data, so it’s just a black box.”
    Since 2008, the F.D.A. has been taking action against companies whose supplements are found to contain prescription drugs and controlled substances, said Daniel Fabricant, the director of the division of dietary supplement programs in the agency’s Center for Food Safety and Applied Nutrition. For example, the agency recently took steps to remove one “fat burning” product from shelves, OxyElite Pro, that was linked to one death and dozens of cases of hepatitis and liver injury in Hawaii and other states.
    The new research, presented last month at a conference in Washington, was produced by the Drug-Induced Liver Injury Network, which was established by the National Institutes of Health to track patients who suffer liver damage from certain drugs and alternative medicines. It includes doctors at eight major hospitals throughout the country.
    The investigators looked at 845 patients with severe, drug-induced liver damage who were treated at hospitals in the network from 2004 to 2012. It focused only on cases where the investigators ruled out other causes and blamed a drug or a supplement with a high degree of certainty.
    When the network began tracking liver injuries in 2004, supplements accounted for 7 percent of the 115 severe cases. But the percentage has steadily risen, reaching 20 percent of the 313 cases recorded from 2010 to 2012.
    Those patients included dozens of young men who were sickened by bodybuilding supplements. The patients all fit a similar profile, said Dr. Navarro, an investigator with the network.
    “They become very jaundiced for long periods of time,” he said. “They itch really badly, to the point where they can’t sleep. They lose weight. They lose work. I had one patient who was jaundiced for six months.”
    Tests showed that a third of the implicated products contained steroids not listed on their labels.
    A second trend emerged when Dr. Navarro and his colleagues studied 85 patients with liver injuries linked to herbal pills and powders. Two-thirds were middle-aged women, on average 48 years old, who often used the supplements to lose weight or increase energy. Nearly a dozen of those patients required liver transplants, and three died.
    It was not always clear what the underlying causes of injury were in those cases, in part because patients frequently combined multiple supplements and used products with up to 30 ingredients, said Dr. Bonkovsky, an investigator with the network.
    But one product that patients used frequently was green tea extract, which contains catechins, a group of potent antioxidants that reputedly increase metabolism. The extracts are often marketed as fat burners, and catechins are often added to weight-loss products and energy boosters. Most green tea pills are highly concentrated, containing many times the amount of catechins found in a single cup of green tea, Dr. Bonkovsky said. In high doses, catechins can be toxic to the liver, he said, and a small percentage of people appear to be particularly susceptible.
    But liver injuries attributed to herbal supplements are more likely to be severe and to result in liver transplants, Dr. Navarro said. And unlike prescription drugs, which are tightly regulated, dietary supplements typically carry no information about side effects. Consumers assume they have been studied and tested, Dr. Bonkovsky said. But that is rarely the case. “There is this belief that if something is natural, then it must be safe and it must be good,” he said.

    'Superbug' bacteria widespread in U.S. chicken: consumer group


    By Charles Abbott
    WASHINGTON (Reuters) - About half of the raw chicken breasts in a nationwide sampling carried antibiotic-resistant "superbug" bacteria, a U.S. consumer group said on Thursday, calling for stricter limits on use of the medicines on livestock.
    It could be more difficult to treat people if they became ill after eating chicken with the antibiotic-resistant bacteria, said Consumer Reports, which describes itself as the world's largest independent product-testing organization.
    The group said it tested for six types of bacteria in 316 raw chicken breasts purchased from retailers nationwide during July. Almost all of the samples contained potentially harmful bacteria, it said.
    Some 49.7 percent carried a bacterium resistant to three or more antibiotics, according to the group, and 11 percent had two types of bacteria resistant to multiple drugs. Resistance was most common for the antibiotics used for growth promotion and disease treatment of poultry.
    Consumer Reports urged passage of a law to restrict eight classes of antibiotics for use only to treat humans and sick animals. The law would be more effective, it said, than the Food and Drug Administration's plan, announced last week, to phase down the non-medical use of antibiotics in livestock over three years.
    In addition, it said the Agriculture Department should set levels for allowable salmonella and campylobacter bacteria in poultry and give its inspectors the power to prevent sale of poultry meat that contains salmonella bacteria that is resistant to multiple antibiotics.
    Chicken is the most widely consumed meat in the United States. Americans are forecast to consume nearly 84 pounds per person in 2014, compared to 53 lbs of pounds of beef and 48 pounds of pork.
    The broiler industry said it will cooperate with the FDA's planned phase-down of antibiotics although it says there is negligible risk from current use of the drugs.
    Consumers should cook poultry to 165 degrees F (73.8C) to kill bacteria and take steps, such as using a separate cutting board for raw meat, to avoid cross-contamination of other foods, Consumer Reports said.
    (Editing by Ros Krasny and Eric Walsh)

    Thursday, December 19, 2013

    Neanderthal Fossil Indicates Incest Was Common

    Researchers examining the DNA extracted from the fossilized toe of a 50,000-year-old Siberian Neanderthal woman believe that the woman was the child of an incestuous relationship.

    The scientific journal Nature, which published the findings, also asserted that incest among Neanderthals was not taboo. The toe bone, found in 2010, yielded to scientists the woman’s genome, and that information was then processed through a number of simulated inbreeding scenarios. The scientists ascertained that the woman’s parents were either half-siblings born from the same mother or double first cousins. It also was theorized that the woman’s parents could have come from different generations of the same extended family.
    University of California at Berkley population geneticist Montgomery Slatkin, a researcher on the project, said that the possible parental combinations could include an aunt/nephew, uncle/niece, grandfather/granddaughter, or grandmother/grandson.
    Deputy Director of the University of Adelaide's Australian Centre for Ancient DNA Jeremy Austin said the period in which the Neanderthal woman lived was an era during which the Neanderthals were going extinct. Consequently, there were fewer choices for breeding. He stated, "On that basis, it's not particularly surprising. You can imagine they would have been living in very small and isolated family groups."
    The team of researchers was led by scientists from Germany's Max Planck Institute of Evolutionary Anthropology. They found that the genome sequence of the woman showed low levels of genetic diversity, indicating a small, sedentary population. The researchers also found that the genome sequence hinted that Neanderthals interbred with the Denisovans and that another human ancestor may have been part of the pattern, possibly Homo erectus.
    Austin was more interested in the possibility of interbreeding between Neanderthals and Denisovans than inbreeding among only Neanderthals. He said, "This new DNA sequence from this toe bone suggests that Denisovans and Neanderthals were also interbreeding.”
    There has already been evidence of interbreeding between Neanderthals and modern humans, as well as between Denisovans and modern humans.

    Monday, December 16, 2013

    The Private Life of the Barn Owl

    BBC - Natural World - Return Of The Eagle Owl

    National Geographic Wildlife Wonders, Owls - The Silent Hunters

    Magic of the Snowy Owl PBS


    From Wikipedia, the free encyclopedia

    Temporal range: Late Paleocene–Recent
    Little Owl (Athene noctua)
    Otus jolandae call
    Scientific classification e
    Kingdom: Animalia
    Phylum: Chordata
    Class: Aves
    Superorder: Strigimorphae
    Order: Strigiformes
    Wagler, 1830
    Ogygoptyngidae (fossil)
    Palaeoglaucidae (fossil)
    Protostrigidae (fossil)
    Sophiornithidae (fossil)
    Range of the Owl, all species.
    Strigidae sensu Sibley & Ahlquist
    Owls are a group of birds that belong to the order Strigiformes, constituting 200 extant bird of prey species. Most are solitary and nocturnal, with some exceptions (e.g., the Northern Hawk Owl). Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish. They are found in all regions of the Earth except Antarctica, most of Greenland, and some remote islands. Owls are characterized by their small beaks and wide faces, and are divided into two families: the typical owls, Strigidae; and the barn-owls, Tytonidae.


    Burrowing Owl (Athene cunicularia)
    Owls have large forward-facing eyes and ear-holes; a hawk-like beak; a flat face; and usually a conspicuous circle of feathers, a facial disc, around each eye. The feathers making up this disc can be adjusted in order to sharply focus sounds that come from varying distances onto the owls' asymmetrically placed ear cavities. Most birds of prey sport eyes on the sides of their heads, but the stereoscopic nature of the owl's forward-facing eyes permits the greater sense of depth perception necessary for low-light hunting. Although owls have binocular vision, their large eyes are fixed in their sockets—as are those of other birds—so they must turn their entire head to change views. As owls are farsighted, they are unable to see clearly anything within a few centimeters of their eyes. Caught prey can be felt by owls with the use of filoplumes—like feathers on the beak and feet that act as "feelers". Their far vision, particularly in low light, is exceptionally good.
    Owls can rotate their heads and necks as much as 270 degrees. Owls have fourteen neck vertebrae as compared to 7 in humans which makes their necks more flexible. They also have adaptations to their circulatory systems, permitting rotation without cutting off blood to the brain: the foramina in their vertebrae through which the vertebral arteries pass are about 10 times the diameter of the artery, instead of about the same size as the artery as in humans; the vertebral arteries enter the cervical vertebrae higher than in other birds, giving the vessels some slack; and the carotid arteries unite in a very large anastomosis or junction, the largest of any bird's, preventing blood supply from being cut off while the neck is rotated. Other anastomoses between the carotid and vertebral arteries support this effect.[1][2]
    The smallest owl—weighing as little as 31 grams (1 oz) and measuring some 13.5 centimetres (5 in)—is the Elf Owl (Micrathene whitneyi).[3] Around the same diminutive length, although slightly heavier, are the lesser known Long-whiskered Owlet (Xenoglaux loweryi) and Tamaulipas Pygmy Owl (Glaucidium sanchezi).[3] The largest owl by length is the Great Grey Owl (Strix nebulosa), which measures around 70 cm (28 in) on average and can attain a length of 84 cm (33 in).[3] However, the heaviest (and largest winged) owls are two similarly-sized eagle owls; the Eurasian Eagle-Owl (Bubo bubo) and Blakiston's Fish Owl (B. blakistoni). These two species, which are on average about 2.53 cm (1.00 in) shorter in length than the Great Grey, can both attain a wingspan of 2 m (6.6 ft) and a weight of 4.5 kg (10 lb) in the largest females.[3][4][5][6][7]
    Different species of owls make different sounds; this wide range of calls aids owls in finding mates or announcing their presence to potential competitors, and also aids ornithologists and birders in locating these birds and recognizing species. As noted above, the facial disc helps owls to funnel the sound of prey to their ears. In many species, these discs are placed asymmetrically, for better directional location.[8][verification needed]
    The plumage of owls is generally cryptic, but many species have facial and head markings, including face masks, ear tufts and brightly coloured irises. These markings are generally more common in species inhabiting open habitats, and are thought to be used in signaling with other owls in low light conditions.[9]

    Breeding and reproduction

    Owl eggs usually have a white color and an almost spherical shape, and range in number from a few to a dozen, depending on species and the particular season; for most, three or four is the more common number. Eggs are laid at intervals of 1 to 3 days and do not hatch at the same time.[citation needed]


    Most owls are nocturnal, actively hunting their prey only in darkness. Several types of owl, however, are crepuscular—active during the twilight hours of dawn and dusk; one example is the Pygmy owl (Glaucidium). A few owls are active during the day also; examples are the Burrowing Owl (Speotyto cunicularia) and the Short-eared Owl (Asio flammeus).

    The serrations on the leading edge of an owl's flight feathers reduce noise

    Owl eyes each have nictitating membranes that can move independently of each other, as seen on this Spotted Eagle-Owl in Johannesburg, South Africa

    Owls yawn
    Much of the owls' hunting strategy depends on stealth and surprise. Owls have at least two adaptations that aid them in achieving stealth. First, the dull coloration of their' feathers can render them almost invisible under certain conditions. Secondly, serrated edges on the leading edge of owls' remiges muffle an owl's wing beats, allowing an owl's flight to be practically silent. Some fish-eating owls, for which silence has no evolutionary advantage, lack this adaptation.
    An owl's sharp beak and powerful talons allow it to kill its prey before swallowing it whole (if it is not too big). Scientists studying the diets of owls are helped by their habit of regurgitating the indigestible parts of their prey (such as bones, scales and fur) in the form of pellets. These "owl pellets" are plentiful and easy to interpret, and are often sold by companies to schools for dissection by students as a lesson in biology and ecology.[10]

    Adaptations for hunting

    All owls are carnivorous birds of prey and live mainly on a diet of insects and small rodents such as mice, rats and hares. Some owls are also specifically adapted to hunt fish. They are very adept in hunting in their respective environments. Since owls can be found in nearly all parts of the world and across a multitude of ecosystems, their hunting skills and characteristics vary slightly from species to species, though most characteristics are shared among all species.[citation needed]

    Flight and feathers

    Most owls share an innate ability to fly almost silently and also more slowly in comparison to other birds of prey. Most owls live a mainly nocturnal lifestyle and being able to fly without making any noise gives them a strong advantage over their prey that are listening for any sign of noise in the dark night. A silent, slow flight is not as necessary for diurnal and crepuscular owls given that prey can usually see an owl approaching. While the morphological and biological mechanisms of this silent flight are more or less unknown, the structure of the feather has been heavily studied and accredited to a large portion of why they have this ability. Owls’ feathers are generally larger than the average birds’ feathers, have fewer radiates, longer pennulum, and achieve smooth edges with different rachis structures.[11] Serrated edges along the owl’s remiges bring the flapping of the wing down to a nearly silent mechanism. Research has shown that the serrations are more likely reducing aerodynamic disturbances, rather than simply reducing noise.[11] The surface of the flight feathers is covered with a velvety structure that absorbs the sound of the wing moving. These unique structures reduce noise frequencies above 2 kHz,[12] making the sound level emitted drop below the typical hearing spectrum of the owl’s usual prey[12][13] and also within the owl’s own best hearing range[citation needed]. This optimizes the owl’s ability to silently fly in order to capture prey without the prey hearing the owl first as it flies in. It also allows the owl to monitor the sound output from its flight pattern.


    Another characteristic of the owl which aids in their nocturnal prey capture is their eyesight. Owls are part of a small group of birds that live nocturnally, but do not use echolocation to guide them in flight in low-light situations. Owls are known for their disproportionally large eyes in comparison to their skull. An apparent consequence of the evolution of an absolutely large eye in a relatively small skull is that the eye of the owl has become tubular in shape.[14] This shape is found in other so-called nocturnal eyes, such as the eyes of prosimians and bathypelagic fishes.[15] Since the eyes are fixed into these sclerotic tubes, they are unable to move the eyes in any direction.[16] Instead of moving their eyes, owls swivel their head to visualize their surroundings. Owl’s heads are capable of swiveling through an angle of approximately 270°, easily enabling them to see behind them without relocating the torso.[16] This ability keeps bodily movement at a minimum and thus reduces the amount of sound the owl makes as it waits for its prey. Owls are regarded as having the most frontally placed eyes among all avian groups, which gives them some of the largest binocular fields of vision. But owls are farsighted and cannot focus on objects within a few centimeters of their eyes.[15][17] While it is commonly believed that owls have such great nocturnal vision due to their large (and thus very light-gathering) eyes and pupils and/or extremely sensitive rod receptors, the true cause for their ability to see in the night is due to neural mechanisms which mediate the extraction of spatial information gathered from the retinal image throughout the nocturnal luminance range. These mechanisms are only able to function due to the large sized retinal image.[18] Thus, the primary nocturnal function in the vision of the owl is due to its large posterior nodal distance; retinal image brightness is only maximized to the owl within secondary neural functions.[18] These attributes of the owl cause the nocturnal eyesight to be far superior to that of its average prey.[18]


    Owls exhibit specialized hearing functions and ear shapes that also aid in hunting. They are noted for asymmetrical ear placements on the skull in some genera. Owls can have either internal or external ears, but those genera exhibiting asymmetrical ear geometry only have external ear placements. Asymmetry has not been reported to extend to the middle or internal ear of the owl. Asymmetrical ear placement on the skull allows the owl to pinpoint the location of its prey. This is especially true for strictly nocturnal species such as the barn owls 'Tyto' or Tengmalm’s Owl.[16] With ears set at different places on its skull, an owl is able to determine the direction from which the sound is coming by the minute difference in time that it takes for the sound waves to penetrate the left and right ears.[citation needed] The owl turns its head until the sound reaches both ears at the same time, at which point it is directly facing the source of the sound. This time difference between ears is a matter of about 0.00003 seconds, or 30 millionths of a second. Like the eyes, which utilize feather movements to focus light, the ears are surrounded by feathers to maximize hearing capabilities. Behind the ear openings there are modified, dense feathers, densely packed to form a facial ruff, which creates an anteriorly-facing concave wall that cups the sound into the ear structure.[19] This facial ruff is poorly defined in some species and prominent, nearly encircling the face, in other species. The facial disk also acts to direct sound into the ears, and a downward-facing, sharply triangular beak minimizes sound reflection away from the face. The shape of the facial disk is adjustable at will to focus sounds more effectively.[16]


    While the auditory and visual capabilities of the owl allow it to locate and pursue its prey, the talons and beak of the owl do the final work. The owl kills its prey by using these talons to crush the skull and knead the body.[16] The crushing power of an owl’s talons varies according to prey size and type, and by the size of the owl. The Burrowing Owl (Athene cunicularia), a small partly insectivorous owl, has a release force of only 5 N. The larger Barn Owl (Tyto alba) needs a force of 30 N to release its prey, and one of the largest owls, the Great Horned Owl (Bubo virginianus) needs a force of over 130 N to release prey in its talons.[20] An owl’s talons, like those of most birds of prey, can seem massive in comparison to the body size outside of flight. The Masked owl has some of the proportionally longest talons of any bird of prey; they appear enormous in comparison to the body when fully extended to grasp prey.[21] An owl’s claws are sharp and curved. The family Tytonidae have inner and central toes of about equal length, while the family Strigidae have an inner toe that is distinctly shorter than the central one.[20] These different morphologies allow efficiency in capturing prey specific to the different environments they inhabit.


    The beak of the owl is short, curved and downward-facing, and typically hooked at the tip for gripping and tearing its prey. Once prey is captured, the scissor motion of the top and lower bill is used to tear the tissue and kill. The sharp lower edge of the upper bill works in coordination with the sharp upper edge of the lower bill to deliver this motion. The downward-facing beak allows the owl’s field of vision to be clear, as well as directing sound into the ears without deflecting sound waves away from the face.[citation needed]

    Snowy Owl blends well with its snowy surroundings


    The coloration of the owl’s plumage plays a key role in its ability to sit still and blend into the environment, making it nearly invisible to prey. Owls tend to mimic the colorations and sometimes even the texture patterns of their surroundings, the common barn owl being an exception. Nyctea scandiaca, or the Snowy Owl, appears nearly bleach-white in color with a few flecks of black, mimicking their snowy surroundings perfectly. Likewise, the Muted Wood-Owl (Strix ocellata) displays shades of brown, tan and black, making the owl nearly invisible in the surrounding trees, especially from behind. Usually, the only tell-tale sign of a perched owl will be its vocalizations or its vividly colored eyes.

    Evolution and systematics

    Great Horned Owl (Bubo virginianus) sleeping during daytime in a hollow tree
    The systematic placement of owls is disputed. For example, the Sibley-Ahlquist taxonomy finds that, based on DNA-DNA hybridization, owls are more closely related to the nightjars and their allies (Caprimulgiformes) than to the diurnal predators in the order Falconiformes; consequently, the Caprimulgiformes are placed in the Strigiformes, and the owls in general become a family Strigidae. A recent study indicates that the drastic rearrangement of the genome of the accipitrids may have obscured any close relationship of theirs with groups such as the owls.[22] In any case, the relationships of the Caprimulgiformes, the owls, the falcons and the accipitrid raptors are not resolved to satisfaction; currently there is an increasing trend to consider each group (with the possible exception of the accipitrids) a distinct order.
    There are some 220 to 225 extant species of owls, subdivided into two families: typical owls (Strigidae) and barn-owls (Tytonidae). Some entirely extinct families have also been erected based on fossil remains; these differ much from modern owls in being less specialized or specialized in a very different way (such as the terrestrial Sophiornithidae). The Paleocene genera Berruornis and Ogygoptynx show that owls were already present as a distinct lineage some 60–57 mya (million years ago), and, hence, possibly also some 5 million years earlier, at the extinction of the non-avian dinosaurs. This makes them one of the oldest known groups of non-Galloanserae landbirds. The supposed "Cretaceous owls" Bradycneme and Heptasteornis are apparently non-avialan maniraptors.[23]
    During the Paleogene, the Strigiformes radiated into ecological niches now mostly filled by other groups of birds.[clarification needed] The owls as we know them today, on the other hand, evolved their characteristic morphology and adaptations during that time, too. By the early Neogene, the other lineages had been displaced by other bird orders, leaving only barn-owls and typical owls. The latter at that time were usually a fairly generic type of (probably earless) owl similar to today's North American Spotted Owl or the European Tawny Owl; the diversity in size and ecology found in typical owls today developed only subsequently.
    Around the Paleogene-Neogene boundary (some 25 mya), barn-owls were the dominant group of owls in southern Europe and adjacent Asia at least; the distribution of fossil and present-day owl lineages indicates that their decline is contemporary with the evolution of the different major lineages of typical owls, which for the most part seems to have taken place in Eurasia. In the Americas, there was rather an expansion of immigrant lineages of ancestral typical owls.
    The supposed fossil herons "Ardea" perplexa (Middle Miocene of Sansan, France) and "Ardea" lignitum (Late Pliocene of Germany) were more probably owls; the latter was apparently close to the modern genus Bubo. Judging from this, the Late Miocene remains from France described as "Ardea" aureliensis should also be restudied.[24] The Messelasturidae, some of which were initially believed to be basal Strigiformes, are now generally accepted to be diurnal birds of prey showing some convergent evolution towards owls. The taxa often united under Strigogyps[25] were formerly placed in part with the owls, specifically the Sophiornithidae; they appear to be Ameghinornithidae instead.[26][27][28]

    The ancient fossil owl Palaeoglaux artophoron
    For fossil species and paleosubspecies of extant taxa, see the genus and species articles.
    Unresolved and basal forms (all fossil)
    • Berruornis (Late Paleocene of France) basal? Sophornithidae?
    • Strigiformes gen. et ap. indet. (Late Paleocene of Zhylga, Kazakhstan)
    • Palaeoglaux (Middle – Late Eocene of WC Europe) own family Palaeoglaucidae or Strigidae?
    • Palaeobyas (Late Eocene/Early Oligocene of Quercy, France) Tytonidae? Sophiornithidae?
    • Palaeotyto (Late Eocene/Early Oligocene of Quercy, France) Tytonidae? Sophiornithidae?
    • Strigiformes gen. et spp. indet. (Early Oligocene of Wyoming, USA)[24]


    • Ogygoptynx (Middle/Late Paleocene of Colorado, USA)


    • Eostrix (Early Eocene of WC USA and England - Middle Eocene of WC USA)
    • Minerva (Middle - Late Eocene of W USA) formerly Protostrix, includes "Aquila" ferox, "Aquila" lydekkeri, and "Bubo" leptosteus
    • Oligostrix (mid-Oligocene of Saxony, Germany)


    Tytonidae: Barn-owls

    Barn Owl (Tyto alba)
    • Genus Tyto – typical barn-owls, stand up to 500 millimetres (20 in) tall. Some 15 species and possibly one recently extinct
    • Genus Phodilus – bay-owls, 1–2 extant species and possibly one recently extinct
    Fossil genera
    • Nocturnavis (Late Eocene/Early Oligocene) includes "Bubo" incertus
    • Selenornis (Late Eocene/Early Oligocene) - includes "Asio" henrici
    • Necrobyas (Late Eocene/Early Oligocene – Late Miocene) includes "Bubo" arvernensis and Paratyto
    • Prosybris (Early Oligocene? – Early Miocene)
    Placement unresolved
    • Tytonidae gen. et sp. indet. "TMT 164" (Middle Miocene) – Prosybris?

    Strigidae: Typical owls

    Long-eared Owl (Asio otus) in erect pose

    Laughing Owl (Sceloglaux albifacies), last seen in 1914
    Fossil genera
    • Mioglaux (Late Oligocene? – Early Miocene of WC Europe) – includes "Bubo" poirreiri
    • Intutula (Early/Middle - ?Late Miocene of C Europe) - includes "Strix/Ninox" brevis
    • Alasio (Middle Miocene of Vieux-Collonges, France) - includes "Strix" collongensis
    • Oraristrix (Late Pleistocene)
    Placement unresolved
    • "Otus/Strix" wintershofensis: fossil (Early/Middle Miocene of Wintershof West, Germany) - may be close to extant genus Ninox[24]
    • "Strix" edwardsifossil (Middle/Late? Miocene)
    • "Asio" pygmaeusfossil (Early Pliocene of Odessa, Ukraine)
    • Strigidae gen. et sp. indet. UMMP V31030 (Late Pliocene) – Strix/Bubo?
    • Ibiza Owl, Strigidae gen. et sp. indet.prehistoric[29]

    Symbolism and mythology


    Among the Kikuyu of Kenya it was believed that owls were harbingers of death. If one saw an owl or heard its hoot, someone was going to die. In general, owls are viewed as harbingers of bad luck, ill health, or death. The belief is widespread even today.[30]

    The Little Owl, 1506, by Albrecht Dürer

    The Americas

    In the culture of the Uto-Aztec tribe, the Hopi, taboos surround owls, which are associated with sorcery and other evils. The Aztecs and Maya, along with other Natives of Mesoamerica, considered the owl a symbol of death and destruction. In fact, the Aztec god of death, Mictlantecuhtli, was often depicted with owls. There is an old saying in Mexico that is still in use:[31] Cuando el tecolote canta, el indio muere ("When the owl cries/sings, the Indian dies"). The Popol Vuh, a Mayan religious text, describes owls as messengers of Xibalba (the Mayan "Place of Fright").[32] The belief that owls are messengers and harbingers of the dark powers is also found among the Hočągara (Winnebago) of Wisconsin.[33] When in earlier days the Hočągara committed the sin of killing enemies while they were within the sanctuary of the chief's lodge, an owl appeared and spoke to them in the voice of a human, saying, "From now on the Hočągara will have no luck." This marked the beginning of the decline of their tribe.[34] An owl appeared to Glory of the Morning, the only female chief of the Hočąk nation, and uttered her name. Soon afterwards she died.[35][36] People often allude to the reputation of owls as bearers of supernatural danger when they tell misbehaving children, "the owls will get you."[37] Also, in the native Cherokee culture, as well as many other Native American cultures, owls are a very bad omen. It is said that if you are outside in the broad day light and an owl flies over your head a family member or loved one would die within the coming week.

    Middle East

    In Arab mythology, owls are seen as bad omens.[38]


    Lakshmi with the owl
    In Hinduism, an owl is the vahana, mount, of Goddess Lakshmi.

    Western culture

    Owl-shaped protocorinthian aryballos, ca. 640 BC., from Greece
    The modern West generally associates owls with wisdom. This link goes back at least as far as Ancient Greece, where Athens, noted for art and scholarship, and Athena, Athens' patron goddess and the goddess of wisdom, had the owl as a symbol.[39] Marija Gimbutas traces veneration of the owl as a goddess, among other birds, to the culture of Old Europe, long pre-dating Indo-European cultures.[40]
    T. F. Thiselton-Dyer in his Folk-lore of Shakespeare says that "from the earliest period it has been considered a bird of ill-omen, and Pliny tells us how, on one occasion, even Rome itself underwent a lustration, because one of them strayed into the Capitol. He represents it also as a funereal bird, a monster of the night, the very abomination of human kind. Virgil describes its death-howl from the top of the temple by night, a circumstance introduced as a precursor of Dido's death. Ovid, too, constantly speaks of this bird's presence as an evil omen; and indeed the same notions respecting it may be found among the writings of most of the ancient poets."[41] A list of "omens drear" in John Keats' Hyperion includes the "gloom-bird's hated screech."[42] Pliny the Elder reports that owl's eggs were commonly used as a hangover cure.[43]

    The coat of arms of Leeds, seen here on Leeds Bridge, displays three owls.
    In France, Belgium and the Netherlands, where owls are divided into eared owls (fr. hiboux / d. oehoes) and earless owls (fr. chouettes/ d. bosuilen), the former are seen as symbols of wisdom while the latter are assigned the grimmer meaning.[citation needed]
    Three Canadian provinces have owls as provincial symbols: the Great Horned Owl in Alberta, the Great Grey Owl in Manitoba, and the Snowy Owl in Quebec.
    Three owls appear on the coat of arms of the English city of Leeds, as the crest and the two supporters. They are derived from the arms of the city's first alderman, Sir John Saville.

    Use as rodent control

    Encouraging natural predators to control rodent population is a natural form of pest control, along with excluding food sources for rodents. Placing a new box for owls on a property can help control rodent populations (one family of hungry barn owls can consume more than 3,000 rodents in a nesting season) while maintaining the naturally balanced food chain.[44]

    Attacks on humans

    Although humans and owls frequently live together in harmony, there have been incidents when owls have attacked humans. In January 2013, a man from Inverness, Scotland went into shock and suffered heavy bleeding after being attacked by an owl, which was likely a 2 foot tall Eagle Owl[45] In 2007, a thief attempted to steal a barn owl named Addy, but was attacked by the owl and suffered a fractured leg and a bruised right eye.[46][47] The photographer Eric Hosking lost his left eye after attempting to photograph a tawny owl, which inspired the title of his 1970 autobiography, An Eye for a Bird.

    Conservation issues

    All owls are listed in Appendix II of the international CITES treaty (the Convention on Illegal Trade in Endangered Species of Wild Fauna and Flora). Although owls have long been hunted, a 2008 news story from Malaysia indicates that the magnitude of owl poaching may be on the rise. In November 2008, TRAFFIC reported the seizure of 900 plucked and "oven-ready" owls in Peninsular Malaysia. Said Chris Shepherd, Senior Programme Officer for TRAFFIC's Southeast Asia office, "This is the first time we know of where 'ready-prepared' owls have been seized in Malaysia, and it may mark the start of a new trend in wild meat from the region. We will be monitoring developments closely." Traffic commended the Department of Wildlife and National Parks in Malaysia for the raid that exposed the huge haul of owls. Included in the seizure were dead and plucked Barn Owls, Spotted Wood Owls, Crested Serpent Eagles, Barred Eagles, and Brown Wood Owls, as well as 7,000 live lizards.[48]