Archive for July, 2008

Jul 12 2008

Goldfinch Time

The songbird nesting season is winding down and many have stopped singing, but yesterday one bird caught my attention.  Singing loudly and flying high, American goldfinches are ready to nest. 

Goldfinches are confirmed seed eaters.  Unlike other songbirds, they don’t feed insects to their young.  Instead they wait for the seeds to ripen, then they assess the crop to choose a site where food is plentiful.  This means they nest in July in Pittsburgh. 

After they’ve paired up, the male claims his territory with a beautiful canary-like song while he slowly flutters in a wide circle above the trees.   He also sings “perchicoree” in an exaggerated roller-coaster flight.  

Meanwhile the female builds her nest in a secret hiding place.  After she lays her eggs she spends 95% of her time incubating.  She doesn’t even stop to eat.  Instead, her mate collects and swallows seeds, then flies his display above her.  If she’s hungry, she calls to him from the nest with a soft “teeteeteeteeteeteetee” sound.  He then flies down and feeds her the partially digested seed. 

Last summer  Karen Lang and I discovered a goldfinch nest near Heinz Chapel on Pitt’s campus.  We saw all the displays I mentioned above – right down to the male feeding his mate - but I didn’t know what I was seeing.  This year I know what to look for.  How happy it made me to see Mr. Goldfinch warbling above the trees at home.

It’s Goldfinch Time!

(photo by Marcy Cunkelman)

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Jul 10 2008

Windows Kill

When our young peregrine died last month, many people wondered how he could crash into a window without even seeing it.

In fact, windows are the number one human-induced cause of death in birds. According to Dr. Daniel Klem, Jr. of Muhlenberg College, up to 1 billion birds in the U.S. die by hitting windows each year. That’s 2.7 million birds per day.

Half of the birds who hit windows actually survive the initial impact but can easily be captured by predators while stunned. Those deaths don’t count as window kills, though they’re related.

Why do windows kill?

Take a look at the building pictured here. Even to us it looks like trees and sky. We’re too large to fit through the “fence” (the window frames that hold each pane) but birds think they can fly through it. Sometimes they see their own reflection and believe it’s a safe flyway because another bird is using it. Other times they can see into the room and try to fly inside. At night they’re attracted by lights.

People are fooled by glass too, but it doesn’t kill us. How many of us have bumped into a glass door because we didn’t see it? We survive because we move slowly – and not head first – into the glass.

How can we prevent window kills?

Sadly, a few decals won’t do the trick. The rest of the window is still dangerous.

Reflective glass must be treated on the outside to alter the entire look of the windows. The treatment must make the birds see a wall or a mesh too small to fly through. For buildings like the one pictured here, it means coating or etching the outside of the glass or installing mesh or outdoor blinds. It would even help – but only a little – if they didn’t wash the windows.

For transparent glass, closing the curtains or slanting the blinds is all you need to do. Window screens for keeping bugs out are excellent deterrents though they need to cover all the glass, not just half.

At night turn off the lights or close the drapes, especially in high-rise structures during spring and fall migration. Toronto, Ontario has begun a program to do just that, thanks to the Fatal Light Awareness Program (FLAP).

There are many resources on the web to help your home or business reduce window kills:

  • There’s a handy fact sheet here with lots of resources and solutions that work.
  • Audubon has suggestions for your home.
  • The Fatal Light Awareness Program has worked on this problem for 15 years. They have lots of suggestions including new research on UV coatings that birds can see but we cannot.
  • A brief paper by Dr. Klem, with in-depth information, can be found here.

If you are an architect or designer or you are considering building a new office or home, think about the windows before you buy them! It’s an uphill battle to change a building after it’s built.

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

 

p.s. Hierarchy of threats to birds from FLAP Toronto.

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Jul 08 2008

Short Rectrices and Remiges

Published by under Songbirds

Eastern Phoebe fledgling (photo by Chuck Tague)

Big words for a little bird.

When Chuck Tague sent me this photo of a newly fledged eastern phoebe, my first reaction was, “Cute bird but where’s his tail?”  And on second thought, “His wings are short, too.”

According to Cornell’s Birds of North America Online, “At normal fledging time, [eastern phoebe] fledglings fly well and are fully feathered. Dimensions, such as weight and tarsus length, approximates that of the adult, but rectrices and remiges are considerably shorter.”

I had to look that up. 

Rectrices are tail feathers (both words have a “T” in them).  Remiges are wing feathers.  Tarsus is the lowest part of the leg.

Eastern phoebes are flycatchers, known for wagging and pumping their tails.  Phoebe Baby is missing his distinguishing feature.  I hope he grows his tail soon.

(photo by Chuck Tague)

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Jul 06 2008

Pizazz!

Published by under Songbirds

Red-headed Woodpecker (photo by Chuck Tague)Here’s a bird you don’t see every day! 

On the Fourth of July I hiked a section of State Gameland #95 in northern Butler County.  I was about to head back to the car when I decided to push a little further to the lake at Slippery Rock Creek.

On the way there I saw a flash of white among the dead snags in the swamp.  So many times I’ve watched the same flash and movement in the 2005 video of the ivory-billed woodpecker that my first reaction was a gasp.  It can’t be!

Well, of course it wasn’t. 

It was a red-headed woodpecker, a much smaller bird whose flight characteristics and white back are reminiscent of the ivory-billed.  Red-headed woodpeckers are unusual nonetheless.  I was very happy to see this one.

The woodpecker sat still for a while.  Then he zoomed up, hawked a large bug out of the air, carried it to a tree trunk and hammered it dead.  I thought he was going to cache it in a crevice, but he carried his prize to a nest hole and poked his head in.  Wow!  This bird has kids.

After dropping off the food he flew back to his perching snag and harassed a northern flicker along the way.  As soon as he perched he was almost invisible.  I would never have noticed him if he hadn’t flown.

When I got home I did some research and was amazed to discover I’d seen most of the red-headed woodpecker’s notable characteristics in one brief moment:

  • Red-headed woodpeckers are conspicuous in flight with their jazzy red, black and white tuxedos.
  • They are expert flycatchers but will also eat mast (tree nuts), waste grain, fruit, bird eggs, just about anything.
  • They fly with powerful flapping (like the ivory-billed woodpecker) not undulating flight like most woodpeckers.
  • They rely on areas of dead trees for nesting.  Their population increased when the chestnut blight killed so many trees.
  • They sit still for long periods of time.
  • They are the most pugnacious North American woodpecker, aggressive toward many birds including northern flickers.
  • They are said to have a playful nature.   (How this accords with aggression, I don’t know.)
  • In fall they migrate during the day, wandering in search of mast.
  • They’re one of only four woodpeckers who store food.
  • Their population is erratic and declining.

So if you see a red-headed woodpecker, count yourself lucky to see such pizazz.  I do.

(photo by Chuck Tague)

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Jul 04 2008

Bald Eagle news

Published by under Birds of Prey

Pair of Bald Eagles in Butler County (photo by Chuck Tague)

Here’s some news about our national bird on the Fourth of July. 

Pennsylvania:  Earlier this week the Game Commission issued a statement about bald eagle nests in PA. 

Great news!  There are more nests than ever.  Last year there were 132 known nests in the state.  This year there will be more than 140. 

Bald eagles are nesting in 47 out of Pennsylvania’s 67 counties.  Interestingly, they are not nesting in most southwestern PA counties – only in Butler, Armstrong and Westmoreland.  This pair, photographed by Chuck Tague, is in Butler County.

Bald eagles are “sea eagles.”  They prefer to eat fish and they nest near water.  With three rivers in Allegheny County – four if you count the Youghiogheny – we’re hoping bald eagles will eventually choose the Pittsburgh area for their home.

Virginia:  You may remember the eagle pair at Norfolk Botanical Garden whom I wrote about on April 16.  Their lives were like Peyton Place but they had an egg and the potential for a successful nest.  Unfortunately their troubles didn’t end.

In mid-May the eagle webcam showed that their one eaglet had a growth on his beak.  Every day the growth got larger.  By May 22, the Virginia Department of Game and Inland Fisheries decided the bird needed to be examined.  When they pulled the eaglet from the nest, they discovered the growth had started to deform his beak.  He was sent to the Wildlife Center of Virginia for treatment and possible surgery. 

Tests showed the eaglet has avian pox, a common bird disease (no danger to people).  He has been getting excellent treatment – even an MRI! - and receiving a regimen of drugs to help him get better.  Meanwhile the growth has shrunk considerably, making future surgery a safer option though his recovery has no guarantee.  He sure is one high-tech eagle!

Back at Norfolk Botanical Garden, his parents consider the year a loss.  They continue to stay at the Garden and will undoubtedly try again next year.  Wouldn’t it be amazing if their eaglet was released some day and came to visit?  They would think he’d come back from the dead. 

(photo by Chuck Tague)

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Jul 02 2008

Red-tail babies: Now we can fly!

Published by under Birds of Prey

Juvenile Red-tailed Hawk at Duquesne University (photo by Jamey Stewart)The nest is empty.

Last week two red-tailed hawks took their first flight from the nest near my office. Several things intrigued me about the way they did it.

First, it took them two weeks to progress from flapping hops to flying away. This seemed to take only a week for the peregrines. Perhaps the learning curve for red-tails is longer because they’re larger and heavier.

Then, in their first flights the red-tails refused to land on trees. Instead they flew to WQED’s building, our satellite dish and a TV antenna. I expected them to land in the trees near their nest but I guess they thought the trees looked scary because they grew up in a gutter.

And then there was the whining. When they were nest-bound I never heard them make a sound. After they flew they became very noisy about food. I found them easily last Friday because they were whining from the floodlights.

So now there are four large, similar-looking hawks outside my office window. How do I tell the difference between the adults and their kids?

As you can guess, behavior is a huge hint. The babies beg and the adults supply food. But what if they’re perched alone?

The easiest field mark is their tail. I’ll use this photo of an immature red-tailed hawk by Jamey Stewart to illustrate. Notice that this bird’s tail, protruding below his two wing tips, is brown with faint horizontal stripes. An adult red-tailed hawk has a rusty red tail. It’s that easy – red versus brown.

There’s one gotcha about this bird that you can’t see here. Jamey sent me two photos of the immature red-tail that visited Duquesne University’s campus last week. One showed the bird’s back and there I clearly saw half-grown rusty red feathers, hidden by his wings in the photo above.

So this immature bird is not a fledging.  Chuck Tague says they begin to grow red tail feathers at about one year old.  Red-tailed hawks take 3-4 years to mature so this bird has some years to go before he’s an adult.

p.s.  Thanks to Chuck for clarifying the age at which the red tail feathers grow.  I also learned that immature red-tails have yellow irises (eyes).  See above!  When red-tailed hawks mature their eyes change to a dark rusty color.

(photo by Jamey Stewart)

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