Outside My Window

For years scientists have said, “Songbirds have a poor sense of smell.” 

Other than turkey vultures’ famous olfactory abilities, word was that most of bird-dom didn’t particularly notice scents.  Songbirds were specifically placed in this category because they have the smallest olfactory bulbs relative to brain size.  However, they do have a lot of olfactory receptors and they must be using them for something — but what?

Danielle Whittaker, managing director of Michigan State University’s BEACON Center, decided to find out.  She and her colleagues tested preen oil scents among three populations of dark-eyed juncos: Carolina, white-winged and Oregon (pictured above).  They used three populations because the scents among subspecies would be different enough to show general scent preferences.

The results were surprising.  Yes, juncos have scent preferences and they use them to attract a mate. 

Female juncos visually prefer larger males but based on scent alone the smaller males won hands down.  They produced more scent and it was far more attractive to the females.  It didn’t matter what population they came from, the ladies came flocking.  “What’s that scent you’re wearing?”  The larger males came too, probably as an aggressive response. 

To me this is revolutionary.  Not only do songbirds have a sense of smell but they use cologne. 

I must say I feel a little betrayed.  For years I went with the scientists’ pronouncement that songbirds can’t smell and passed it on to friends and readers.  Now I find out it’s wrong.

Forget what I told you in the past.  Of course birds can smell!

Click the photo for Science Daily‘s article or here for the full report from Michigan State’s BEACON Center.

(photo of dark-eyed juncos linked from Science Daily, courtesy of Michigan State University BEACON)

… are closer than they appear!

The passenger’s mirror message takes on a whole new meaning.

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(photo by David Kay via Shutterstock.com)

Steve Valasek and his family visited Pittsburgh last month and spent some time at the Pittsburgh Zoo.  While there they saw an amazing episode at the African Savannah exhibit. 

Steve wrote, ”A male Red-Winged Blackbird was attacking an Ostrich in the enclosure.  The bird would land on the Ostrich’s back and peck or pull its feathers.  There was a female Blackbird around too, so I’m assuming that there was a nest nearby.”

Whatever the cause, I can tell the blackbird is angry.  Look at his red shoulders!

Zoom!  The blackbird attacks the ostrich. 

The ostrich takes a few steps but not enough.  The blackbird attacks from behind…

…then circles back for another attack.

Victory!  The blackbird lands on the ostrich while his mate watches from above.

 ”I don’t care how big you are!” says the blackbird, “Get out of here!”  

The blackbird won the battle but not the war.  The ostrich isn’t going to leave the enclosure. 

Fortunately the ostrich was merely annoyed.

For Steve’s entire photo sequence, click here.

(photos by Steve Valasek)

It looks like these Steller’s jays are overcome by the heat but they’re actually sunbathing on Michelline Halliday’s roof in Seattle. 

Today is the wrong day to sunbathe in Pittsburgh!  The high will be 94^oF but the heat index will make it feel like 102^o.   Last night at 9:00pm it was still 89^o with a heat index of 97^o.   This morning it was 80^oF at dawn.  And did I mention that the air will be bad?  Stay indoors.

Today it will be only 69^oF in Seattle.  (I’m so jealous!)

Even so, it looks like one jay is saying to the other,  “Hot enough for you?”

(photo by Michelline Halliday)

Song is an important territorial and mate-attraction signal for birds so how do they cope when there’s a lot of noise?

Many songbirds abandon noisy settings but some can handle it by changing their songs.

Dr. Clinton Francis of the National Evolutionary Synthesis Center in Durham, NC studied two species of western vireos in noisy areas and found that both altered their songs so they could be heard. 

Gray vireos (Vireo vicinior) sang longer songs and raised the pitch of their highest notes while plumbeous vireos (Vireo plumbeus) sang shorter songs and raised the pitch of their lowest notes.

Where do these birds live that it’s so noisy?  Near natural gas compressor stations in rural New Mexico.   The compressors roar non-stop at more than 95 decibels. 

Pennsylvania has a lot of compressor stations in Marcellus Shale drilling areas.  Maybe Dr. Francis will study our birds.

Read more here in Science Daily.

And here’s a similar study done in Colorado.

(photo by Clinton Francis of the National Evolutionary Synthesis Center, linked from the Science Daily article)

Is this bird sleep deprived?  And if so, how does he make up for it?

Several years ago the Max Planck Institute for Ornithology answered these questions by studying sleep in pigeons. 

Prior to the study, they knew that birds experience two phases of sleep — slow wave sleep (SWS) and rapid eye movement (REM) — just like mammals do. 

SWS is deep, dreamless sleep during which the brain shows synchronous, slow oscillations of neurons as shown on an EEG (electroencephalogram).  SWS alternates with dreaming sleep, called REM (rapid eye movement) because the eyes move rapidly during this period even though the lids are closed.  

To study sleep in pigeons researchers prevented the birds from taking naps, something they like to do late in the day.  (I do too!)  

The pigeons were allowed to sleep normally at night when researchers learned that the birds made up for their sleep loss by more intense periods of SWS.  Their slow-wave-sleep lasted the same amount of time as before but during SWS the number of slow waves was much higher.  In other words, they slept more deeply.

Mammals do this too under similar conditions.   We all “power sleep” when especially tired.

So what did the pigeons think of this experiment?

I’ll bet it made them grumpy.

(photo by Derek Ramsey (Ram-Man) licensed via Wikimedia Commons. Click on the photo to see the original.)

Peregrine falcon chicks and baby robins aren’t the only ones learning how to fly right now. 

This year’s “baby” red-tailed hawks are learning too.   They’re the same size as their parents but they’re clumsy fliers and often have trouble landing.

Even when they fly well enough to follow their parents they don’t know how to hunt.  In this they have a lot in common with the young peregrines at Pitt. 

How to get a meal?  Ask mom and dad!   Make sure they know you’re hungry!  Make sure they notice you!

The juveniles of both species spread and wave their wings to attract their parents’ attention.    ”Look at me!  I’m starving!”

And they whine a lot!  Young red-tails and peregrines are both so loud that people often think they’re hurt.  On Tuesday at Pitt the whining of just one peregrine chick on a 32nd floor ledge of the Cathedral of Learning was so loud I could hear it a quarter of a mile away on Craig Street!

Immature red-tails easily attract human attention even when they can hunt on their own.  One summer I saw a young red-tail whining while he was hunting.  He perched on a fence and whined at a mouse in the grass while he waited for the opportunity to pounce on it.  The mouse escaped, of course.

Don’t be surprised if you see and hear young red-tailed hawks in the next month or two.  Neil Gerjouy found this one waving his wings in Point Breeze last summer. 

(photo by Neil Gerjuoy)

Steve Valasek sent me this photo of a raven landing and said, “We visited Acoma Pueblo on Monday and saw many ravens riding the updrafts on the sides of the mesa.  Our guide said that he’s actually seen them fly upside down.”

You bet they fly upside down!

Ravens are very acrobatic fliers.  I’ve seen them tumble together many times as they launch over the cliffs at Acadia National Park in Maine.  They seem to get a lot of joy from doing this and might even be competing to see who can make the best moves.

It’s so hard to describe how cool they are that I found a video of ravens sky-tumbling at Lundy Island, Great Britian.  Watch carefully at 29, 40 and 44 seconds and you’ll see one of them completely flip over sideways.  Awesome!

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Ravens are cool, but for speed you can’t beat a peregrine.  While searching for the first video, I found this one of a peregrine  harrassing two ravens at Culver Cliff, Isle of Wight.  The big soaring birds are ravens.  The very fast, smaller, flapping bird that appears from above at 3 seconds and 13 seconds is the peregrine.

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Let’s tumble!

(photo by Steve Valasek)

For days now we’ve been focused on birds who eat birds (peregrines, for instance) without thinking much about the lives of the birds who become dinner. 

Fortunately for them, small birds have several defense mechanisms for avoiding birds of prey.  To avoid a peregrine in the city, they stay low.  To avoid other hawks they say in thick cover.  When there’s no cover handy they freeze in position, hoping the predator won’t notice them.

Here’s a pair of downy woodpeckers at Marcy Cunkelman’s house, frozen on her porch railing to avoid being seen by a passing hawk. 

Don’t move! 

The hawk didn’t see them.  It worked.

(photo by Marcy Cunkelman)

Courtship is well underway among Pittsburgh’s resident birds.

On sunny days red-tailed hawks seem to be everywhere, soaring to claim territory and court their mates.  Sometimes you can’t tell the difference between courtship and chasing.  Is he driving away an intruder or impressing his mate?  And, my heavens, his scream sounds scary!  (Read more about red-tail courtship here.)

Because I love watching peregrines and hawks, I often pay attention to their favorite food: pigeons.  That’s how I noticed that rock pigeons make courtship flights, too.

Most of pigeon courtship occurs on the ground but there are two flight behaviors that tell you they’re courting. 

The first is wing clapping in which a pigeon takes off from the flock making a loud snapping sound as he claps his wings together at the top of his upstroke.  This behavior is usually initiated by a male to advertise his sexual maturity.  His action often prompts other members of the flock to take off and clap their wings as well.

The other display occurs when a pair breaks off from the flock in flight.  Eventually one or both will soar with their wings held upright in a stiff V.

I’ve sometimes seen a trio break away and fly together but only two of them do the V flight.  I’ll bet these trios are one female with two males and the guys are trying to impress her.  It certainly looks less dangerous than what red-tails do!

(photo from Shutterstock)