Owls see as humans do

Humans and birds may be more similar than previously thought

Date:  July 2, 2018

Source:  Society for Neuroscience

Summary:

A study of barn owls published in JNeurosci suggests the visual systems of humans and birds may be more similar than previously thought.

The ability to perceive an object as distinct from a background is crucial for species that rely on vision to act on their environment. One way humans achieve this is by grouping different elements of a scene into "perceptual wholes" based on the similarity of their motion. This phenomenon has been mostly studied in primates, leaving open the question of whether such perceptual grouping represents a fundamental property of visual systems in general.

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Weird Looking Birds Freak Out Indian City

By Interrobang Staff on November 21, 2017

This video of a couple of birds found in a gas station bathroom went viral around a port city in India – people didn’t know what they actually were. They also could be aliens sent to spy on the bathroom habits of Indian people on Earth. That’s always a possibility.

http://www.worldstarhiphop.cvom/embed/114250

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Close encounters of the BIRD kind! Feathered creatures with spooky dark eyes are mistaken for ALIENS by Indian builders... but turn out to be barn owls

The feathery predators were filmed on a construction site in Visakhapatnam 

The adolescents birds are turning from chicks into adults in Andhra Pradesh

Eastern barn owls are closely related to the western barn owls found in Britain

By Liz Dunphy For Mailonline

PUBLISHED: 13:48, 20 November 2017 | UPDATED: 15:02, 20 November 2017

A video shared by Indian builders of so-called aliens turned out to be startled barn owls. 

The feathery predators were filmed on a construction site in Visakhapatnam, capital of the south-eastern Indian state of Andhra Pradesh. 

The builders who filmed them can be heard talking excitedly as two of the three owls stare at them with large dark eyes. 

The birds are adolescents, just moving from being chicks into adulthood. 

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Barn owls found to suffer no hearing loss as they age

September 20, 2017 by Bob Yirka report

(Phys.org)—A small team of researchers with the University of Oldenburg has found that barn owls do not suffer hearing loss as they get older. In their paper published in Proceedings of the Royal Society B, the group describes hearing tests they conducted with a group of trained owls, what they found and why they believe more study of the birds may lead to preventing hearing loss in aging humans.

Most everyone knows that growing older can lead to hearing loss. It happens because humans and other mammals have an inability to regenerate sensitive cells inside the ear. As damage accumulates over time, hearing degrades. This is not the case with birds, however. Prior research has shown that some experience little if any hearing loss in their old age. In this new effort, the researchers looked to see if that also applied to long-lived birds such as the barn owl.

Barn owls are the most widespread of all the owls—they are found all around the world except in polar and desert regions. They earned their name by taking up residence in barns, drawn by the rodents that are attracted to stored grains. Barn owls have exceptionally good hearing—approximately 10 times as sensitive as human hearing, according to previous research. Barn owls are able to use hearing alone to capture prey moving in total darkness. They also live a long time—some in captivity have lived to be over 20 years of age.

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Barn owls threatened by Africanized bees in South Florida

Date:  June 19, 2015

Source:  University of Florida Institute of Food and Agricultural Sciences

Summary:  Throughout the past two decades, researchers have seen barn owl populations in the Everglades Agricultural Area, centered around Belle Glade, expand from mere dozens to more than 400 nesting pairs. But these beneficial raptors, currently listed as a threatened species, are now being threatened by Africanized honey bees.

Swarming as frequently as eight times per year, the invasive bees have been taking over nesting boxes Raid and students have built for the owls, using them as hives, and displacing or even killing the desired raptors.

"In 20 years, we've never had any problems with any other critters moving into our boxes," said Raid, a plant pathologist for UF's Institute of Food and Agricultural Sciences. "But the Africanized honey bees became established in 2005 and are spreading throughout the peninsula of Florida."

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Barn owl boxes in Suffolk 'stolen and vandalised'

Five barn owl boxes which are part of a Suffolk community project have been stolen or vandalised, with the animals taken to "spend their lives in cages".

The boxes were erected in an attempt to halt a decline in barn owl numbers.

They are made by a group of disabled people and Hollesley Bay prisoners, and monitored by volunteers.

Kathy Piotrowski, of the Suffolk Community Barn Owl Project, said it was sad that a "few mindless people" were undoing people's hard work.

About 1,700 boxes have been put up around the county and they have been credited with helping to turn around the birds' fortunes locally.

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Barn owl bumper brood in Cambridgeshire celebrated

Conservationists are celebrating after barn owls nesting at a Cambridgeshire farm hatched twice as many chicks as this time last spring.

Three pairs of birds at Lark Rise farm have produced 17 chicks in total and may have a second brood this summer.

The UK barn owl population was hit badly last year after a late spring.

Vince Lea, from The Countryside Restoration Trust which runs the farm, said the brood was "the biggest ever" in the 12 years since the owls arrived.

"We had no owls in this area for a long time, then eventually they started to nest and generally we'd have about three chicks per pair each year," he said.

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Yorkshire's hatched barn owl eggs spark recovery hopes

7 May 2014 Last updated at 18:17

Two out of six barn owl eggs laid in a nest box in North Yorkshire have hatched sparking hopes of a population recovery.

Wildlife conservationist Robert Fuller, from Thixendale, put up 10 nest boxes in the area last year to help the birds survive and breed.

A clutch of six barn owl eggs were laid by a breeding pair last month.

The Yorkshire Wildlife Trust warned that recent harsh winters had left the barn owl numbers "at an all time low".

The two eggs hatched on Tuesday night.

Mr Fuller, who has put up a total of 150 nest boxes over the last five years, is monitoring the remaining four eggs, which he expects to hatch in the next few days.

The Trust, which is running a campaign to save barn owls, said the number of breeding pairs in the UK was estimated to be 4,000 in the mid 2000s. Last year it dropped to 1,000.

The charity said the barn owl population had been in decline since World War Two due to the loss of habitat and nest sites, but the recent "run of bad winters, and the prolonged snow of March 2013 had left the UK's population of barn owls at the lowest it has ever been".

http://www.bbc.co.uk/news/uk-england-york-north-yorkshire-27314911

Why Do Barn Owls Divorce?

Posted by Jennifer S. Holland in Weird & Wild on April 29, 2014

Love is a fickle thing—even in barn owls. These normally monogamous birds sometimes call it quits and move on to new partners—nearly a quarter of the time, in fact, says a new study published April 28 in the Journal of Evolutionary Biology. Among people in the U.S., the divorce rate is about 40 percent.

And while these “divorces” may mean sacrificing quality for quantity, both sexes can benefit from the split.

On a faithful note, barn owls tend to divorce only when breeding isn’t going well—for example, if there are only a few eggs laid or not many surviving chicks. When a pair is making a lot of babies, the birds remain quite loyal—and that chick-making relationship only gets better with time because the two mate more often, potentially maximizing the size of the family long-term.

Sometimes, It’s Splitsville 

Amélie N. Dreiss and Alexandre Roulin, of the University of Lausanne, Switzerland, studied a population of free-living barn owls in western Switzerland for 24 years, observing how the pairs bonded and how many babies they had.

Barn owls are productive parents, often laying two broods per year with up to 11 (an average of six) eggs per brood.

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Barn Owls - via Ghostman Raines - heard about on Radio Devon

Out of 145 Barn Owls found dead through accidents (66%), starvation (32%), shooting (2%) and poisoning (<1%), 10% contained residues of rodenticides, difenacoum or brodifacoum, in their livers. Difenacoum was in the range 0.005-0.106 microg g(-1) fresh weight, and brodifacoum was in the range 0.019-0.515 microg g(-1). Minimum levels of detection were about 0.005 microg g(-1) for both chemicals. Mice fed for 1 day on food containing difenacoum and brodifacoum died after 2-11 days. Within these mice residues were present at greater concentration in the liver than in the rest of the carcass. The mean mass of residue in a whole 35g mouse was estimated at 10.17 microg (range 4.73-20.65 microg) for difenacoum and 15.36 microg (range 8.07-26.55) for brodifacoum. Such poisoned mice were fed to Barn Owls for successive periods of 1, 3 and 6 days. All six owls fed on difenacoum-dosed mice survived all three treatments, in which up to an estimated 101.7 microg of difenacoum was consumed, and the coagulation times of their blood returned to near normal in less than 5-23 days. Four of the six owls fed on brodifacoum-dosed mice died 6-17 days after the 1-day treatment, but the survivors also survived the 3-day and 6-day treatments. Those that died had each eaten 3 mice, with a combined weight of about 105g and a total brodifacoum content of about 46.07 microg, which was equivalent to a dose of 0.150-0.182 mg kg(-1) of owl body weight. After death these owls had 0.63-1.25 micro g(-1) of brodifacoum in their livers. Blood from the survivors would not coagulate at 9 days post-treatment, but did so at 16 days in one bird and between 38 and 78 days in the other. It is concluded that: (1) Barn Owls in Britain are now widely exposed to second-generation rodenticides; (2) not all owls exposed to these chemicals are likely to receive a lethal dose; (3) brodifacoum is more toxic to owls than difenacoum; and (4) while there is yet no evidence that rodenticides have had any appreciable effect on Barn Owl populations in Britain, further monitoring of residue levels and population trends in desirable.

Barn owl nestlings recognise their siblings' calls

Barn owl nestlings recognise their siblings' calls, according to researchers.

Instead of competing aggressively for food, young barn owls are known to negotiate by calling out.

A team of scientists in Switzerland discovered that the owlets have remarkably individual calls.

They suggest this is to communicate each birds' needs and identity in the nest.

The findings were announced in the Journal of Evolutionary Biologyby Dr Amelie Dreiss and colleagues at the University of Lausanne, Switzerland.

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We must act now to save beautiful owls under threat

BARN owls in Worcestershire are under threat in what is being described as “the worst breeding season for 30 years”.

The Worcester Barn Owl Conservation Group (WBOCG) has found numbers of the popular farmland bird have decreased dramatically since 2009, with only four nests found in a recent survey, compared to the usual 13.

Bird numbers usually start to increase once the weather starts to get warmer after the winter but a report by the British Trust for Ornithology found deaths had increased by 208 per cent at the end of March this year.

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Barn Owl Project to help preserve endangered birds

In Thailand, people believe that barn owls will bring them bad luck. Let's say if the bird is resting on the roof of someone's house, it is believed that death is brought there at their door step. Someone will die.

However, a group of Thais today are trying to change such superstitions, for they say that barn owls are in fact quite useful in helping farmers catch and kill rats and mice on their farms.

Such help is obvious in oil palm plantation and rice paddy fields. Usually, a barn owl catches and eats one or two rats every day, making a big dent on the rat population at 350-700 rats annually.

Having the birds in your farm then becomes a very good thing, but due to the Thai belief and ratsbane and other poisons used on farms, the number of barn owls has dropped dramatically almost to the point of extinction.

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