That Really Is a Live Owl's Eyeball, Seen Through Its Ear

By Mindy Weisberger, Senior Writer | February 7, 2018 06:14am ET

Some say that eyes are the windows to the soul. But in owls, the ears are literally windows to the animals' eyeballs.

Unnerving glimpses of the inside of an owl's head — in which a view of the bird's sizable bluish-white eyeball is visible through its ear hole — were captured in photos by writer and naturalist James McCormac, author of "Birds of Ohio" (Lone Pine Publishing, 2004), who shared the images with Live Science.

Like all birds, owls lack the external ear structures found in most mammals; the birds' ears are unadorned openings in their skulls, visible only when the feathers on the sides of the animals' heads are parted. But these owls' unusually large earholes and eyes also offer a "behind the scenes" peek at their visual system, showcasing the evolutionary adaptations in sight and hearing that make the birds so successful at stealthy nighttime hunting, McCormac told Live Science. [Whooo Knew? 10 Superb Facts About Owls]

McCormac photographed his owl subjects — northern saw-whet owls (Aegolius acadicus) — in southern Ohio during a data-collection initiative by Project Owlnet. In this effort, scientists and members of the public track this owl species to understand the bird's migration patterns.

Twice a year — in the fall and spring — participants in the project use audio recordings that mimic the owls' calls to lure the animals into nets, and then the researchers attach bands to the owls' legs, according to the Project Owlnet website. Before the birds were released, McCormac had the opportunity to take a closer look at their heads — and to snap photos of the gaping holes showing the bulging sacks of the animals' eyeballs, he told Live Science.

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Asia’s Harry Potter obsession poses threat to owls

From Indonesia to India, wild birds are being sold as pets to families who want their own Hedwig. Ecologists call for protection to help species survive

Robin McKie

Saturday 12 August 2017 21.44 BSTLast modified on Sunday 13 August 2017 06.43 BST

The Harry Potter phenomenon has broken publishing and cinema box-office records and spawned a series of lucrative theme parks. But wildlife experts are sounding the alarm over a sad downside to JK Rowling’s tales of the troubled young wizard. The illegal trade in owls has jumped in the far east over the past decade and researchers fear it could endanger the survival of these distinctive predators in Asia.

Conservationists say the snowy owl Hedwig – who remains the young wizard’s loyal companion for most of the Harry Potter series – is fuelling global demand for wild-caught birds for use as pets. In 2001, the year in which the first film was released, only a few hundred were sold at Indonesia’s many bird markets. By 2016, the figure had soared to more than 13,000, according to researchers Vincent Nijman and Anna Nekaris of Oxford Brookes University in a paper in Global Ecology and Conservation. At around $10 to $30, the price tag is affordable to most middle-class families.

The issue is of critical concern because the owls being offered for sale are nearly all taken from the wild. “The overall popularity of owls as pets in Indonesia has risen to such an extent that it may imperil the conservation of some of the less abundant species,” Nijman and Nekaris say.

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Owls' wings could hold the key to beating wind turbine noise

Date:  July 4, 2017

Source:  IOP Publishing

Summary:  Inspiration from owls' wings could allow aircraft and wind turbines to become quieter, suggests a new study. Researchers studied the serrations in the leading edge of owls' wings, gaining new insight into how they work to make the birds' flight silent. Their results point towards potential mechanisms for noise suppression in wind turbines, aircraft, multi-rotor drones and other machines.

Read on  

Traffic noise reduces wild owls' foraging efficiency

Date: September 27, 2016

Source: Hokkaido University

A team of researchers has found that traffic noise reduces the foraging efficiency of wild owls by up to 89 percent. The team's world-first study examined how different levels of such noise affect the hunting efficiency of these nocturnal predators, which employ a keen auditory sense to locate prey in the darkness.

As transportation networks rapidly develop around the world, concerns have been heightening over the adverse effects of traffic noise on wild animals, particularly "acoustic predators," which depend on their acute sense of hearing to catch prey. However, as it is difficult to observe wild owls' nighttime foraging activities, the hypothesis that traffic noise reduces the hunting efficiency of acoustic predators was unsubstantiated prior to this study.

The team of researchers from Hokkaido University's Graduate School of Agriculture, the Forestry and Forest Products Research Institute, and California Polytechnic State University developed an artificial prey rustling sound to attract owls and thus facilitate observation of the birds' nighttime hunting pursuits. From December 2014 to March 2015, the team conducted experiments at 103 locations in Yufutsu Plain in Hokkaido and Sendai Plain in Miyagi Prefecture -- both in northern Japan -- where owls overwinter. In the experiments, researchers scrutinized the foraging activities of 78 owls (45 short-eared owls and 33 long-eared owls) while playing back different levels of recorded traffic noise and a constant level of an artificial prey rustling sound.

Read more

Owls' ability to hunt impaired by noise, research shows

Date: June 2, 2016

Source: Boise State University

Researchers have determined that noise has the potential to degrade owl habitat. The study by Jesse Barber, assistant professor of biology at Boise State University, and Tate Mason, a Boise State alumnus and education coordinator for The Peregrine Fund, is the first to examine the impact of noise on a predatory bird. Their findings were recently published in the journal Biological Conservation under the title "Anthropogenic noise impairs owl hunting behavior."

In the study, northern saw-whet owls hunted mice in a field-placed flight tent under the same acoustic conditions found 50-800 meters (55-875 yards) from a natural gas compressor station.

Owls are specialized avian hunters, and many are particularly well adapted to hunting by ear. In this study, researchers challenged 31 owls to hunt mice by ear (in the absence of light) under varying noise conditions. In this way, the independent effect of noise on hunting could be measured. Data showed that the owls experienced an 8 percent drop in hunting success per decibel increase in noise.

Read more … 

Silent flights: How owls could help make wind turbines and planes quieter

Date: June 21, 2015

Source: University of Cambridge

Summary: A newly designed material, which mimics the wing structure of owls, could help make wind turbines, computer fans and even planes much quieter. Early wind tunnel tests of the coating have shown a substantial reduction in noise without any noticeable effect on aerodynamics.

Early tests of the material, which mimics the intricate structure of an owl's wing, have demonstrated that it could significantly reduce the amount of noise produced by wind turbines and other types of fan blades, such as those in computers or planes. Since wind turbines are heavily braked in order to minimise noise, the addition of this new surface would mean that they could be run at much higher speeds -- producing more energy while making less noise. For an average-sized wind farm, this could mean several additional megawatts worth of electricity.

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Salem warns of aggressive owls after multiple attacks

Alisha Roemeling, Statesman Journal6:05 p.m. PST January 31, 2015

An owl has struck again in Bush's Pasture Park, swooping down on the scalps of unsuspecting joggers.

After multiple reports this month of runners being attacked by the large birds, city parks workers have placed signs in the park to warn people of aggressive owls during nesting season.

Two signs were erected this week near the eastern wooded area of the park, near the parking lot on Mission Street SE. The sign indicates that the trail is closed, but the area is not roped off.

According to Keith Keever with the Parks Operations Division, the city was alerted to an owl attack Monday, which prompted them to briefly close the area. Monday's report was the second in three weeks. The city received a third report of an owl encounter Wednesday evening.

"We closed the area for about an hour Monday morning following the recommendation of some Audubon experts," said Keever. "But we can't close all the trails in the park, so we decided to just put up some warning signs so people know about the issue."

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Federal judge shoots down lawsuit to end owl, bird shootings near New York City airports to protect planes

Judge John Gleeson ruled that the feds and the Port Authority were carrying out the bird-hazard reduction plan within legal limits. The lawsuit was filed by a Colorado-based advocacy group last year following the fatal shootings of three snowy white owls.

BY JOHN MARZULLI 

NEW YORK DAILY NEWS 

Friday, October 3, 2014, 7:44 PM

A federal judge has shot down a lawsuit that sought to stop the killing of snowy white owls and migratory birds near New York City airports so they would not pose a threat to aviation.

Friends of Animals, a Colorado-based advocacy group, filed the suit last year in Brooklyn Federal Court in response to the fatal shootings of three snowy white owls at Kennedy Airport.

Judge John Gleeson ruled that the feds and the Port Authority were carrying out the bird-hazard reduction plan within legal limits, but expressed hope that they could “find the tools to diminish the danger to planes without killing so many birds.”

Jennifer Barnes, a lawyer for Friends of Animals, said she was disappointed and would explore options pertaining to whether the ruling could be appealed.

It was disclosed during the litigation that nearly 9,000 birds of various species were killed at city airports in 2012 to prevent them from being sucked into jetliners’ engines — a situation that can bring down a plane. A bird strike was blamed for the engine failure that forced hero pilot Chesley Sullenberger to land a U.S. Airways jet in the Hudson River in 2009.

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Chile: Owls drafted in to fight deadly hantavirus

Officials in Chile are turning to an unlikely ally - wild owls - as they try to fight a contagious disease that has already caused about 15 deaths, it seems.

Owls are the natural predators of the rats carrying the deadly hantavirus, the Santiago Times newspaper reports. Long-tailed pygmy rice rats transmit the virus to humans as they come into contact with campers in the forest, while foraging for bamboo.

But forest fires during Chile's summer months have forced the rats into urban areas, making more people sick. The disease does not affect the rats themselves.

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Why are owls attacking people in Missouri?

Strange days in Missouri. Why strange? KY3 News has been receiving multiple reports that people in southeast Springfield have been “attacked” by owls, plural, or perhaps just one particularly aggressive owl.

There’s Timmery Clark, who sent the station a picture of a bird just hanging out on the back of her head. Clark told KYTV, “It was very gentle--I thought it might hurt me, but both times it very calmly and gently settled on my head (even though I was laughing and screaming). It was pretty surreal, but a funny moment to have caught on film!”

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The Secrets of Owls' Near Noiseless Wings

Nov. 24, 2013 — Many owl species have developed specialized plumage to effectively eliminate the aerodynamic noise from their wings -- allowing them to hunt and capture their prey in silence.

A research group working to solve the mystery of exactly how owls achieve this acoustic stealth will present their findings at the American Physical Society's (APS) Division of Fluid Dynamics meeting, held Nov. 24 -- 26, in Pittsburgh, Pa. -- work that may one day help bring "silent owl technology" to the design of aircraft, wind turbines, and submarines.

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Veeries Very Quiet When Owls Are About

July 30, 2013 — Study shows birds eavesdrop on owls and change their dusk singing patterns to avoid becoming potential prey

If you hear an owl hooting at dusk, don't expect to catch the flute-like song of a Veery nearby. This North American thrush has probably also heard the hoots, and is singing much less to ensure that it does not become an owl's next meal.

veery

Research by Kenneth Schmidt of Texas Tech University and Kara Loeb Belinsky of Arcadia University in the US, published in Springer's journal Behavioral Ecology and Sociobiology, provides insights into just how eavesdropping between predators and prey around dusk may be shaping communication in birds.. The study is the first to use the playback of recorded owl vocalization at sunset to study how birds change their behavior when potential predators are heard nearby.

Perching birds are generally more exposed during periods of extended singing. They are less vigilant and their song can often attract the attention of a predator to their fixed location. Despite this risk, dawn and dusk chorusing is a common trait. One such perching bird is the Veery (Catharus fuscescens), a common small brown and white thrush that is most active during the day. Its most common call is a harsh, descending "vee-er," from which the bird gets its name. This particularly vocal bird has a breezy, flute-like song, a pronounced dusk chorus and is often heard singing well after sunset.. This behavior could potentially expose the bird to predation.

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How owls swivel their heads

By Jonathan Amos

Science correspondent, BBC News

It's the owl's greatest trick - turning its head almost a full circle.

The puzzle has been how the bird doesn't throttle itself in the process. If we did it, we'd cut the blood supply to our brains and pass out.

But according to two US-based scientists, the owl has some very smart bone and vascular structures running along its neck to the skull.

These features protect blood vessels from damage and maintain the flow even when the head is swivelled 270 degrees.

"They haven't developed just one answer to the problem; they have several answers," said Dr Philippe Gailloud from Johns Hopkins University School of Medicine.

"And it's because of this set of solutions that we don't see lots of owls lying on the forest floor having suffered strokes," the interventional neuroradiologist told BBC News.

Most birds have extremely flexible necks, but the owls are the avian species that have perhaps garnered the greatest attention for their neck-twisting exploits.

They must turn their heads in this extraordinary way because of their eyes' narrow field of view and relative immobility.

It's true they have double the number of bones in their neck compared with us - 14 versus seven cervical vertebrae. But it's really the way the animal manages the flow of oxygenated blood to its brain that underpins the impressive feat.

Continued: http://www.bbc.co.uk/news/science-environment-21279609

If You Cut Down a Tree in the Forest, Can Wildlife Hear It?

Dec. 14, 2012 — A new tool developed by the Wildlife Conservation Society (WCS) and its partners is being used by scientists and land managers to model how noise travels through landscapes and affects species and ecosystems -- a major factor in land and wildlife management decisions such as where to locate new roads or recreational trails.

The tool, SPreAD-GIS, uses spatial data layers to predict how sound spreads from a source through the surrounding landscape and how it is affected by such factors as vegetation, terrain, weather conditions, and background sound levels. By determining how sound propagates, potential impacts to wildlife can be forecasted. Such impacts can include reducing habitat quality, altering the geographic distribution of species, disrupting animal communication, and causing stress.

In an example discussed in the paper, the sensitivities of humans and owls to motor vehicle sound levels were compared. The results of the SPreAD-GIS analysis showed that in the same location, motor vehicle noise would affect owls in an area 45 percent larger than the area affected for humans. Exposure to noise may affect an owl's livelihood as the animal relies on its acute sense of hearing to detect even the slightest movement of its prey.

Read on:  http://www.sciencedaily.com/releases/2012/12/121214112614.htm

Owls' Ability to Fly in Acoustic Stealth Provides Clues to Mitigating Conventional Aircraft Noise

ScienceDaily (Nov. 19, 2012) — Owls have the uncanny ability to fly silently, relying on specialized plumage to reduce noise so they can hunt in acoustic stealth. Researchers from the University of Cambridge, England, are studying the owl's wing structure to better understand how it mitigates noise so they can apply that information to the design of conventional aircraft.

They present their findings at the American Physical Society's (APS) Division of Fluid Dynamics meeting, held Nov. 18 -- 20, in San Diego, Calif.

"Many owl species have developed specialized plumage to effectively eliminate the aerodynamic noise from their wings, which allows them to hunt and capture their prey using their ears alone," said Justin Jaworski with the department of applied mathematics and theoretical physics at the University of Cambridge. "No one knows exactly how owls achieve this acoustic stealth, and the reasons for this feat are largely speculative based on comparisons of owl feathers and physiology to other not-so-quiet birds such as pigeons."

All wings, either natural or engineered, create turbulent eddies as they cut through the air. When these eddies hit the trailing edge of the wing, they are amplified and scattered as sound. Conventional aircraft, which have hard trailing edges, are particularly noisy in this regard.

Continued:  http://www.sciencedaily.com/releases/2012/11/121119104525.htm

India’s owls threatened by illegal trade

India's Festival of Lights darkens the future for owls

November 2012. TRAFFIC, the wildlife trade monitoring network, is warning of a possible increase in illegal owl trade and owl sacrifices around Diwali, the Hindu Festival of Lights, which this year falls on 13th November.

Owls are sacrificed on auspicious occasions such as Diwali and their body parts used in ceremonial rituals, when Shaman (black magic practitioners also referred to as tantriks) prescribe various uses for owls and their body parts, including the skull, feathers, ear-tuffs, claws, heart, liver, kidney, blood, eyes, fat, beak, tears, eggshells, meat and bones.

The owl is sacred in Indian culture
"It is unfortunate that although many people consider the owl sacred in Indian culture and a vehicle (vahan) of Goddess Lakshmi, superstitions and false beliefs manipulated over the ages have created a demand for owls and their body parts in black magic ceremonies," said TRAFFIC's Abrar Ahmed, an expert on the Indian bird trade.

Large species sought
Although hunting and trade in all Indian owl species is banned under the Wildlife (Protection) Act 1972, hundreds of owls are trapped and traded every year. Owl species most highly sought after by traders are large species, particularly those with false "ear-tufts" (feather extensions on the head), since these are considered to have the greatest magical properties.

In 2010, TRAFFIC released Imperilled Custodians of the Night, a report highlighting the various ways owls or their body parts are used in black magic, street performances, taxidermy, consumption, occult medicines, for capturing other birds and even their eggs used for gambling.

Continued:  http://www.wildlifeextra.com/go/news/india-owl.html