Outside My Window

Do owls hoot more when the moon is full?

Eurasian eagle owls do.  Maybe great horned owls do too.

In 2009 biologists conducted a study in Spain to find out if moonlight influenced Eurasian eagle owl vocalizations. They radio-tagged 26 breeding eagle owls and tracked them continuously during all phases of the moon.

When the scientists analyzed the data they found that the amount of hooting was directly correlated to the amount of moonlight.  On new moon nights the owls hardly hooted, but as the moon got brighter they had more to say and they said it from higher perches where their white throat patches gleamed in the moonlight as they spoke.

The white throat patch is important.

Like our great horned owls (Bubo virginianus), Eurasian eagle owls (Bubo bubo) have white throat feathers that are only visible when they hoot.  (The owl in this picture is hooting even though we can’t hear him.)  In bright moonlight the white throat patch is apparently a visual cue that backs up the sound.  Perhaps it helps the mate or rival find the bird that’s vocalizing.

Tonight the moon is full.   Will our great horned owls be talking?   Listen…

(photo by Adam Kumiszcza from Wikimedia Commons. Click on the photo to see the original)

Three readers alerted me to this video that’s sweeping the Internet.

In Russia, a hooded crow repeatedly surfs down a snowy roof, riding something that looks like a Frisbee.  When the video begins, there’s already a surf-track on the roof, evidence that he’s been doing this for a while.

Crows just want to have fun. 

(video from YouTube)

UPDATE, 23 Jan 2012: If you click on the video today you’ll see that it is no longer available because of a copyright claim.  This is good!  This is how copyright protection should and does work.  When someone claims a copyright has been infringed, the material is removed from the Internet.  SOPA and PIPA would have done more than remove the content.  They would shut down YouTube — or this blog for linking to it.

Two heads are better than one.  Are twenty better than two?

Among humans this is certainly the case.  The more people working together on a problem, the more likely it will be solved quickly.  Each person’s unique talents contribute to the whole and larger groups are more likely to contain someone with the right skills.  In sociology this is called the pool of competence.

Last September the Proceedings of National Academy of Sciences published a study by Oxford University of the pool of competence among birds.  In Europe there are social birds similar to our chickadees, though larger, called the great tit (Parus major) and the blue tit (Cyanistes caeruleus).  Both species are curious and learn from each other.

To test the birds’ ability, researchers set up intricate bird feeder problems for the flocks at Oxford’s Wytham Woods.  The feeders were equipped with levers and blocking devices that the birds could eventually bypass to get the seeds.

Smaller flocks took a long time to solve the puzzle but the larger the flock, the faster the problem was solved, making the seed accessible to all.  The surprise was that there was no upper limit on flock size after which this advantage tailed off.

Twenty is better than two.  Thirty is better than twenty.  More is better in the pool of competence.

Click here to read more about this study.

And… in this photo these birds look a lot like chickadees but they’re much more colorful.  Click here to see the great tit’s beautiful yellow belly and black stripe.  Click here for a better view of the blue tit.

(photo of a great tit and blue tit by Martin Mecnarowski via Wikimedia Commons. Click on the image to see the original.)

Mirror, mirror on the wall
Who’s the smartest of them all?

Based on our definition of smartness, humans always win this contest.  One of the ways we measure is this:  Is the animal self-aware?

A classic test for determining self-awareness is the mirror test developed by Gordon Gallup, Jr. in 1970.  In it, an animal is marked with an odorless spot that he can see only when standing in front of a mirror.  If the animal looks in the mirror and grooms or touches the spot, it indicates he understands his own reflection.  He flunks the test if he thinks his reflection is another animal (a rival, for instance) or if he looks behind the mirror to find the other animal.

My cat has flunked the mirror test so often she has stopped looking in mirrors.  She even flunks the birds-on-TV test because she looks behind the television to find the birds.

Only a few animals have passed the mirror test.  These include chimpanzees, gibbons, bonobos, orangutans, dolphins, orcas, Asian elephants, European magpies, pigeons (in a video test) and humans more than 18-24 months old.  Yes, baby humans flunk the test.

Even New Caledonian crows, known to be extremely smart, don’t recognize themselves in mirrors but they know how to use them.  A study published last fall showed that New Caledonian crows can see a reflection of hidden food and immediately retrieve the food using the mirror.

Unfortunately most birds flunk the mirror test and some of them waste a lot of time doing it.  During the breeding season birds often mistake their own reflections for rivals and attack mirrors relentlessly.

Mockingbirds don’t even wait for the breeding season.  They’re territorial all year.  This one attacked his own reflection in a car mirror in November in Florida.  Peggy Sherman took photographs and tells the story here on her Camping Tales blog.

This mockingbird shouldn’t feel too bad about flunking.  We humans recognize ourselves in mirrors but most of us still don’t understand how mirrors work.  We tend to think that someone else we see in a mirror can see himself in the mirror too.  Nope.  We only see each other.

(photo by Peggy Sherman on her Camping Tales blog)

This video is sweeping the Internet.  If you haven’t seen it yet you’ll love watching this huge starling flock, called a murmuration, swirling above two girls canoeing in Ireland.

Starlings flock in large numbers in the winter when they’re getting ready to roost.  If the flock sees a predator, each bird pulls in closer to his neighbor until the mass of birds looks like a solid swirling ball.

This flock must feel threatened — they’re flying that close!

And I wonder  … where’s the peregrine?

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(video by Liberty Smith and Sophie Windsor Clive on Vimeo.  Read about their encounter in this article at the Huffington Post.)

Yesterday at the lake at Moraine State Park I saw some blue jays across the cove.  I didn’t pay much attention until I heard an unusual noise coming from their direction.  Was there a green heron over there?

I checked with my binoculars.  No green heron.  Just three blue jays and an immature sharp-shinned hawk. 

The jays were having fun.  The hawk was not.

The blue jays loafed in the trees and waited for the hawk to attack.  The sharpie swooped but the jays always evaded him.  One jay in particular taunted the hawk by flying close and allowing the hawk to chase him.  This must have given the jay an adrenaline rush because the sharpie was faster and sometimes nearly tagged the jay.  At those exciting moments the jay made a green heron noise.

This game went on for 20 minutes.  The hawk could not win.  He was exactly the same size as the blue jays and his speed and anger were no match for their cunning brains.  The sharpie burned a lot of energy but he was not going to quit.

It ended when the “green heron” jay got bored and flew away.

At last the sharp-shinned hawk could focus on finding a meal of an appropriate size.

(Immature sharp-shinned hawk and blue jay; both photos by Marcy Cunkelman)

Today we travel with the BBC to Indonesia where we find a drab bird with an unusual skill:  interior decoration.

Male Volgelkop bowerbirds don’t have beautiful plumes to attract the ladies so they compensate by building and maintaining beautifully decorated bowers where they ultimately mate with the females.

The bower is no nest.  It’s a work of art which requires constant maintenance over a period of years.  Each feature must be placed to its best advantage, then replaced when it fades or goes out of fashion.

To make his bower easy to find, the male announces it using his amazing voice which can mimic almost any sound.  The birds in this video seem to prefer Star Wars’ sounds.

If everything works as planned the male attracts a mate.

Watch the video to see how it’s done and learn a valuable lesson:  It pays to decorate with flowers.

(video from BBC One on YouTube)

On a recent browse through Science Daily I came upon this amazing headline:  Songbirds With Bigger Brains Have Benefited from the End of Communism.

What?

A 17-year study of bird population trends in Germany and the Czech Republic has revealed differences in bird populations that correlate with the end of communism in East Germany and Czechoslovakia.

The study by the German Biodiversity and Climate Research Centre (BiK-F) and Czech Charles University used data collected by “Dachverband Deutscher Avifaunisten” (Federation of German Avifaunists) from 1991 to 2007 and analyzed 57 species, comparing habitat and diet needs, migration strategy, and relative brain size to population trends in each region.

During that 17-year period habitat in western Germany didn’t change much but habitat in the former communist nations did.  The urban centers created new green spaces and there was a housing boom in the suburbs which decreased green habitat there.

The result was that birds with bigger brains thrived while those with small brains declined.  The former communist areas now have a lot more common magpies, blue tits, grey tits, and Eurasian jays (pictured above) and fewer whitethroats (warblers).

According to Dr. Katrin Boehning-Gaese, researcher at BiK-F and professor at Goethe-University, “Relative brain size reflects species’ cognitive abilities. The increase of such songbirds suggests that species with good cognitive abilities might have been better able to adapt to rapid socioeconomic change and make use of the novel opportunities that arose after the end of communism.”

And so I present this logical conclusion:

• The United States has been a capitalist country for more than 200 years.
• Our native birds with the biggest brains are corvids.
• If capitalism benefits brainy birds we ought to have a lot of crows.
• And we do.

Crows are consummate entrepreneurs.

Quod erat demonstrandum Q.E.D.

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p.s.  Read more about the study here.  It is far more complicated than the headline suggests.

(photo of a Eurasian jay by Hans-Jörg Hellwig from Wikimedia Commons.  Click on the image to see the original)

Last Saturday we encountered some unexpected flying objects at Acadia.

The first was a one-man helicopter the size of a Volkswagen beetle.  It appeared over the mountain just above the trees and quickly and quietly maneuvered into the valley behind the Asticou Inn where it landed in a tiny clearing the size of a parking space.

By the time we got there it was tethered like a horse, its rotor tied to the front with a long strap.  We had never seen such a small quiet helicopter but we obviously don’t travel in the right circles. 

That was the well-behaved flying object. The second was another story.

It happened while my husband and I sat on the shoreline boulders, watching the waves and eating lunch.  There was a Labor Day crowd on the Shore Path and some were feeding the gulls.  We were not, but the local gulls knew that handouts were a possibility.

I was holding my sandwich up, ready to take a bite, when I saw a herring gull about to land on me.  His pink legs and large wings filled my view.  He was nearly on top of my sandwich when I shouted and ducked.  The gull flew over me… and hit my husband on the head!  My husband nearly dropped his sandwich but the gull could not snatch it. 

Foiled in his attempt at our food the gull flew over the water and stole a crab from an unsuspecting eider.  How dare he!  It actually made me mad.

Herring gulls apparently do this the world over.  This photo is from Belgium.

(photo from Wikimedia Commons. Click on the photo to see the original.)

Australian brush turkeys don’t incubate their eggs and they don’t feed or protect their young.  The species survives because their eggs are incubated in compost heaps and their chicks are born super-precocial.

The compost heaps, called incubator mounds, are huge — about 10 feet wide and 4.5 feet deep.  Brush turkeys construct them by scraping a pit and filling it with a huge pile of decaying leaf litter covered over with loose soil.

Several females lay eggs in the same mound but after laying the females leave them alone. 

Because temperature is key to incubation the males tend the mounds, testing the temperature by inserting their beaks and adding or removing leaf litter to maintain the correct 91.4⁰ to 95⁰F temperature.

Parental care ends there.

Unlike American wild turkeys (no relation), brush turkeys don’t protect their young.  The chicks hatch inside the mound and dig their way out.  When they emerge they’re able to walk, feed themselves and even fly!  They’re not just precocial, they’re super-precocial.  They fly better than the adults.

Watch this video from Science Friday (5 Nov 2010) to see how well a baby brush turkey can fend for himself.

(video from Science Friday)