Monthly Archives: November 2010

Crow Diary

Flock of crows (photo from Shutterstock by Romeo Mikulic)
Flock of crows at dusk (photo from Shutterstock by Romeo Mikulic)

11 November 2010

Wake up. Get ready to go. Round up the family and head out.

Travel 10 or 20 miles and stop for food.

Look for a popular place.  It’s nice to be with a happy crowd.

Have a good meal.  Meet some old friends.  “Hey, how’s the family?  Haven’t seen you since last winter.”  Swap some stories, enjoy the food.

Everyone has a good time.

End of the day, it’s time to head back.

Travel back those same 10 or 20 miles.

What a crowd!  Jostle for a good place to rest.

Noisy neighbors.

“Come on, folks, I’m trying to sleep!  Caw! Caw!”

Silence.

Night.

(photo from Shutterstock by Romeo Mikulic)

Crow Roost in Oakland

Crows coming to roost in Pittsburgh (photo by Sharon Leadbitter)
Crows coming to roost in Pittsburgh (photo by Sharon Leadbitter)

I was inspired to write the Crow Diary after I visited the roost last night in Oakland.

As I predicted the time change has forced evening rush hour to coincide with the crows’ return to the roost so it’s much easier to keep tabs on them.  My friends and I call each other with the news.

Tony Bledsoe told me he had to “run the gauntlet” early yesterday morning to avoid crow poop falling from the trees near Crawford Hall.

Last night I went to see.  When I got out of the car at Bigelow and Ruskin, it smelled like I was in the presence of a lot of birds.  The crows were silent and almost impossible to see.  They weren’t “in” the trees.  They were on top of them.

Using binoculars I was able to count an average number of crows per tree: 55.  In the nine trees on Ruskin Avenue: about 500.

Most of the tall trees in that neighborhood north of the Cathderal of Learning had crows on them, but the crows were silent.  The pedestrians below had no idea that thousands of birds were sleeping above them.

Pittsburgh’s winter crows move their roost location a little every day.  By next week they might not be near Crawford Hall.

p.s. As you can see from the Diary, I think crows speak in short sentences.  😉

(photo by Sharon Leadbitter)

Winter Weeds: Purple-headed Coneflower


The trees are bare and the flowers are gone but I won’t stop going outdoors just because the growing season is over. 

There’s still a lot to see in winter.  The herbaceous plants have become interesting identification challenges. 

Have you ever seen a brown plant skeleton and wondered what it was?  I have and I’d like to learn more, so today I’m beginning a Wednesday series on identifying weeds in winter.

I mentioned this idea to Marcy Cunkelman and she was already on top of it with a collection of photographs from her garden.  Marcy knows her winter weeds because she doesn’t clear her garden in the fall.  If you haven’t cleared yours yet, don’t do it!  Leave the flowers standing.  (I’ll tell you why next week.)

Before we begin, here are some tips that will help you identify winter weeds.  These are expanded from a great book that has helped me a lot:  Weeds in Winter, written and illustrated by Lauren Brown, W. W. Norton, 1976.  The book has pen-and-ink drawings of the weeds and a helpful key system based on these fieldmarks:

  • Smell the plant.  This is a great clue.  Crush the fruit, seeds, leaves or stem.  If it smells like mint, it’s in the mint family.  If it smells like parsley or carrots it’s in the parsley family.  Smoky smell is the daisy family, burning rubber smell is the tomato family.  The list goes on.
  • Look at the leaves.  How are they arranged on the stalk?  Opposite each other or alternate?  Wrapping the stem or freestanding?  Rough or smooth?  Note their shape, if still recognizable.
  • Look at the stem.  Is it fuzzy? Smooth?  Shiny?  Thorny?  Rough?  Triangular?  Square?
  • Notice where the plant is growing (if it isn’t in a garden).  In a swamp?  On a dry hillside?  In a meadow or a forest?  By a road?
  • Are similar plants nearby?   Your individual plant may be damaged or imperfect but similar plants will provide the characteristics of the species.
  • Look at it thoroughly.  Sometimes the seed pod is your best clue, as we will see today.

So, to begin.

Our first “Winter Weed” is Purple-headed Coneflower (Echinacea purpurea).  Its skeleton stands two to five feet high on a sturdy, rough stem.  Its leaves are alternate on the stem, toothed, egg-shaped and very rough on both sides like fine sandpaper.  As far as I can tell, it doesn’t smell.

When the flower first bloomed the central disk was flat but as the flower matures the disk rises into a cone.  In winter the seed cone looks like a bristly thistle, but don’t expect it to look that way for long.  American goldfinches love these seeds and will cling to the stem to pick them off. 

The goldfinches already ate half of Marcy’s coneflower seeds.  Now you can see the cone.

(photo by Marcy Cunkelman)

Happy Birthday Blog!


Outside My Window is three years old today.

Back in 2007 I started blogging when WQED’s Web Director, Joan Guerin, said I told good stories about birds and should write them down.  Little did I know that my effort would last this long and attract so many readers.

When I began I was afraid I’d run out of things to say but that worry is laid to rest.  Peregrines give me more than enough to write about from February through June.  Birds, flowers, trees and insects occupy spring, summer and fall.  Winter is fallow so I plan a series such as Friday’s Bird Anatomy lessons to keep me going.  I thought I’d be done with anatomy by now, but birds have more body parts than I expected.  😉

Outside My Window has done more than I expected, too.  Here are some surprising statistics:

There’s one more thing I didn’t expect:  Blogging has changed my life.  I now spend part of every day writing and I even get up early to do it.  I’ve made a whole new set of friends — you, my readers — and look forward to meeting more of you in the coming year.

Thanks so much for your support.  You inspire me to keep writing every day.

(Birthday crow by Joan Guerin at WQED)

p.s. Do you have a favorite post?  A suggestion for new topics?  Leave a comment and let me know.

bird-thday

This is a Gray Squirrel


Yes, really.

Black squirrels are not a new species, they’re just a common melanistic color phase of the eastern gray squirrel (Sciurus carolinensis).

“Melanistic” comes from the Greek word for black, melanos, and is caused by melanin, the brown or black pigment that gives hair, skin and eyes a dark color.  Melanin can be inherited for a permanent dark color as in this squirrel, or it can be produced in greater quantities during tanning or in some diseases.

Melanism can confer a biological advantage when it provides better camouflage.  There’s even an effect called “industrial melanism” in which the majority of a species living in a dirty, industrial zone are darker than those who live in a cleaner environment.  This was famously documented among peppered moths in Britian during the sooty, late-1800s.

Who knows why Pittsburgh has black squirrels (we haven’t been sooty for half a century) but if you want to see them come on over to the area of Schenley Park that borders — you guessed it — Squirrel Hill.

 

(photo by D. Gordon E. Roberston from Wikimedia Commons.  Click on the photo to see the original)

Beyond Bounds: Cryptic Forest Falcon

Cryptic Forest-Falcon (photo linked from MSNBC slideshow of the Amazing Amazon)
Cryptic Forest-Falcon (photo linked from MSNBC slideshow of the Amazing Amazon)

Here’s a bird I doubt you’ll ever see in the wild.

This is the cryptic forest-falcon (Micrastur mintoni) of the southern Amazon watershed.  It is so shy and so hard to see that until 2002 its museum specimens were thought to be a similar bird, the lined forest-falcon. Both have slate gray backs and red-orange cere and lores.

Forest-falcons hunt in thickly forested habitat so their bodies have many of the same characteristics as our accipters:  short rounded wings, long tails, and relatively long legs.  The cryptic forest-falcon is somewhat comparable in size and shape to our sharp-shinned hawk.

If you happen to go to the Amazon to look for this bird, good luck.  My raptor guide says it is “best located by song: single low-pitched notes uk, uk, uk..

Thanks to Diane Korolog for alerting me to this beautiful bird.

(photo is linked from MSNBC‘s Amazing Amazon slideshow.  Click on the picture to watch the slideshow. It is the second photo in the series.)

.http://msnbcmedia.msn.com/j/MSNBC/Components/Slideshows/_production/ss-101025-amazon-new-species/Micrastur_mintoni%201.ss_full.jpg

Clock Change


Tonight’s the night.  We gain an hour of sleep.  We lose an hour of evening daylight.

When we turn the clocks backward from Daylight Savings Time to Standard Time the transition is smoothed by giving us all a well rested Sunday morning but I must admit I’m not fond of the change.  It’s a shock to my system when the sun sets at 6:11pm tonight, then at 5:10pm tomorrow.

Last March when we turned the clocks forward it took me almost a week to get used to it.  Obviously I live by the clock.  If I was a bird I’d live by the sun, leaving the roost at sunrise and returning at sunset. 

And that’s the one advantage of changing time zones without going anywhere.  We’ll get a new view of what the birds are doing. 

Starting Monday evening I’ll be leaving the office at sunset, the perfect time to watch the crows.

(animated nature clock by Nevit Dilmen on Wikimedia Commons.  Click the image to see the original.)

Anatomy: Wax Eaters

Yellow-rumped warbler in breeding plumage (photo by Chuck Tague)

5 November 2010

Last week we learned that the stages of birds’ digestive tracts are in a different order than our own so that the heaviest parts are at their center of gravity while they fly.

After birds swallow their food they chemically digest it (proventriculus), then “chew” it in the gizzard.  If they swallow something indigestible and bulky, they regurgitate it as a pellet.  Some species even get nutrition from normally indigestible substances, a talent that has further modified their digestive systems.  The yellow-rumped warbler is one example.

Wax is impossible to digest for most animals and birds.  Its description as a “saturated long-chain fatty acid” even sounds dangerous (saturated!  fatty!) yet the yellow-rump depends on wax for its winter food.  This makes it unique among warblers, most of whom eat insects and must leave North America by September to survive.  The yellow-rump sticks around because it switches its diet to wax-coated bayberries.

How has the yellow-rump’s digestive system adapted to do this?  They have higher levels of gall bladder and intestinal bile-salt than other birds and their digestive system absorbs the food more slowly.  They probably even process it for a longer time, possibly moving it back and forth so the gizzard can grind it again.

The yellow-rumps’ love of bayberry myrtle also gave them an alternate name.  The eastern subspecies is called the “myrtle warbler.”

So now you know why yellow-rumped warblers don’t go far south in the winter:  They’re eating waxy berries.

(photo of a springtime yellow-rumped warbler by Chuck Tague)

Biofuel Affects Bird Diversity


If you garden for birds you know that what you plant has a huge effect on the variety of birds in your yard.  This applies on a larger scale as well.

In recent years our government has encouraged the development and manufacture of biofuels to replace our dependence on foreign oil.  The typical method is to grow corn and refine it into ethanol.  This has spawned a debate on the wisdom of converting valuable farmland into acreage devoted to fuel instead of food and using the corn supply to feed our cars. 

But corn, a labor intensive crop that must be planted every year, is not the only source of biofuel.  Perennial grasses like switchgrass work as well.

When our government provides subsidies to grow biofuel feedstock, even marginal land will be converted to this purpose.  Does it matter what we plant?  Indeed, it does.

Last month two researchers from the University of Wisconsin-Madison published a study on the effect of bioenergy crops on bird diversity in the Upper Midwest.  Using bird surveys and land use maps, Claudio Gratton and Tim Meehan calculated the change in bird diversity when marginal land is planted in annual monocultures (corn) versus a mixture of perennial prairie plants and grasses.

Their results are shown in the maps above.  Brown is bad — species decline up to 50%.  Blue is good — species increase up to 200%. 

Can you guess which map is which? 

The lefthand map shows bird diversity declines up to 50% if we plant monocultures of corn for biofuel.  The righthand map shows that bird diversity doubles if we plant diverse grasslands.

It’s no surprise that monocultures are bad but the results are frightening.   Click here to read more about this in Science Daily.

(image linked from Science Daily.  Click on the image to read the article.)