Monthly Archives: March 2012

Singing In The Dark

Migration, Songbirds

The robins are here!

Migrating flocks of American robins swept north overnight and arrived in Pittsburgh in the dark.  They’re pausing to tank up before continuing their journey north.

In the morning I see them everywhere but I know they arrived, even before dawn, because  I hear them singing in the dark.

The big flocks began arriving Monday night.  Lots of them and more every day.

Because I live in the city I miss hearing another great nighttime sound — spring peepers — so the robins are my only spring night cue.

I do wonder, though, what happens where both robins and spring peepers occur.

Do spring peepers drown out the sound of robins when they’re singing in the dark?

 

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

Winter Trees: Speckled Alder

Trees, Winter Weeds & Trees


Spring is coming fast but there are still a couple of weeks before the tree buds open.  This tree, however, will bloom very soon so we’ll need to identify it now.

Speckled Alder (Alnus incana) is a shrub-like tree in the birch family that grows in wet places at streams, lakes and wetlands.  In winter its branches are distinctive because they carry two kinds of buds with last year’s fruit.

The inch-long male catkins are reddish in winter.  They begin to turn yellow in March just before they bloom into long, yellow pollen flowers.

The female flower buds are small and drooping just ahead of the catkins on the branch.  They look like tiny unopened versions of the seed-bearing cones they’ll become.

The cones are present, too.  Half an inch long they’re last year’s fruit.  All three are visible in the photo above.  The male and female flowers are shown below.

 

Speckled Alder gets its name from the whitish lenticels that speckle its dark bark.  With all these points of interest we hardly notice the small reddish leaf buds.

As you explore stream banks and lake sides for signs of spring, keep an eye out for Speckled Alder.

Someone* told me it carries the past (cones), present (male catkins) and future (female buds) on each branch.

(photo by Marcy Cunkelman)

 

(*) Was it Esther Allen who said this tree is Past, Present and Future?

 

Half The Seabirds Are In Decline

Water and Shore

Though seabirds make up only 3.5% of the world’s bird species, a new study by BirdLife International has found they’re the most threatened group of birds on the planet.

Of the 346 seabird species, including albatrosses, petrels, shearwaters and storm-petrels, half are in decline.  More than half of those (28% total) are at the highest risk level.

Albatrosses could well be the first to disappear.  17 of the 22 species of albatross are threatened with extinction.

The threats come from starvation in over-fished areas, death at the hands of huge commercial fishing operations, and nest failure at their breeding colonies from rats and feral cats.

These threats are induced by humans.  With some effort we could fix them.   For example, some of the breeding colonies have been saved through island rat eradication efforts.

I’ve never seen an albatross but I know the world would be a poorer place without them.

(photo of the critically endangered Amsterdam Albatross by Vincent Legendre on Wikimedia Commons.  Click on the photo to see its original)

March Flowers Bring…

Phenology

If April showers bring May flowers, what do March flowers bring?

In this case, scavenging flies.

Yesterday I found a huge patch of skunk cabbage blooming at Raccoon Creek State Park.  They were so well camouflaged that I had to be careful where I stepped.  I tried for a picture of the flowers hidden inside the spathe but was unsuccessful.  Of course the pollinators don’t need to see the flower.  They’re attracted to the smell.   I stepped on one by accident and yes, it smelled awful.

Also found blooming in wet places are the long, yellow catkins of American hazelnut trees. Here are some from Marcy Cunkleman’s garden.

 

The warm weather fooled me into thinking spring had sprung, but this field at Raccoon brought me back to reality.  How brown!

Spring still has a long way to go.

(skunk cabbage and field scene photos by Kate St. John, catkins photo by Marcy Cunkelman)

Gulf Tower Clue?

Peregrines

For more than a week Pittsburgh’s peregrine watchers have wondered why Louie and Dori aren’t visiting their nest at the Gulf Tower.  Where are they?

Katie Munsch and Dan Costa found a clue.  Yesterday morning they were startled to hear loud wailing coming from Katie’s 19th floor balcony at Point Park University in Downtown Pittsburgh.  Since they couldn’t see the balcony from her window, they went outdoors to investigate and found this peregrine falcon!

Katie was worried about its behavior.  The bird had been wailing, it attempted to spread its wings a couple of times but opened only one, and it allowed them to come quite close.  Was it injured?  She called the Pennsylvania Game Commission.

The Game Commission advised her to poke the falcon with a broom to determine whether or not it was injured.  When Dan approached with a broom it flew away without effort.  The bird was OK but Katie was puzzled so she posted a comment on my blog and sent me Dan’s pictures.

My first reaction was “Wow!”

Katie asked:

  • Did I think this bird was male or female?  — She looks female to me.
  • What did the sound mean?  — If the sound was a wail, then it was annoyed and telling a challenger (peregrine or hawk) to go away.
  • Why did the bird let them come within 3-4 feet of it?  –For this peregrine, Dan and Katie were not as big a threat as whatever it was looking or waiting for.

I had some questions, too.

  • Did the peregrine have bands?  –Dan and Katie couldn’t tell because the bird always faced away.
  • Was the sound a wail like this?  –Yes!  Definitely the warning wail.  This might be Dori, warning away an intruder, or it may be the intruder herself, warning away Dori.  (I don’t know Dori’s face well enough to identify her by this photo.)
  • Was the bird grooming?  –Which would explain why it opened only one wing at a time.

By 4:00pm I was free to go investigate.  On my way Downtown I stopped at Pitt and found Dorothy calmly perched on the Cathedral of Learning, facing the nest.  Good!

Downtown, I drove with the window open to listen for wailing but heard none.  I searched the Gulf Tower perches and surrounding buildings for peregrines.  None.

Next stop, First Side.  I walked around and scanned Lawrence Hall and the surrounding buildings for peregrines.  None.  I was beginning to think my search was hopeless when I heard a robin making alarm calls and saw him tilting his head toward the sky.  I followed his gaze and found a peregrine perched 13 stories above us on a roof ornament of the West Penn Building.

When I stepped back for a better look the peregrine looked at me and flew away.  It was not wailing but it was using the territorial flappy flight that signals, “This is mine!”

I can’t guess who this peregrine was, but now I know where the peregrines are focusing their attention:  at First Side, less than half a mile from the nest.

Thanks to Katie and Dan we have a clue to the Gulf Tower mystery.

(photo by Dan Costa)

 

p.s.  If you see any peregrines in Downtown Pittsburgh, please post a comment here!  We want to know what’s going on.

Killdeer’s Broken-Wing Display

Bird Behavior, Nesting & Courtship

When I wrote about killdeer nests on Tuesday, Emily and Kurt left comments reminding us that these birds lure danger away from their nests by pretending to be injured.

Here’s a video showing the killdeer’s broken-wing display, a convincing bit of play-acting.  The adult looks gravely injured to attract the predator’s attention.  As soon as the predator has been lured away from the eggs or babies, the killdeer makes a miraculous recovery and flies away.

In the video you can see why the adult is so worked up.  A very cute baby killdeer runs away from the intruder at 5 seconds into the video and another hides in the grass at the 25-second mark.

Mama Killdeer thought he was scary but the man with the videocam was helping her family.  He was herding her babies out of the street where the traffic was dangerous.

(video taken in Boise, Idaho by gogrimm, posted on YouTube)

An Ancient Grackle?

Bird Anatomy

 

If you ever saw this bird, you might think it was a cross between a grackle and a scissor-tailed flycatcher because of its iridescent blue-black color and long, thin tail feathers.

But it’s not a bird.  This is a drawing of a Microraptor, a pigeon-sized dinosaur that lived 130 million years ago.  We know what it looked like thanks to extensive research published in yesterday’s issue of the journal Science, and this image by Mick Ellison of AMNH.

The research was a collaboration of American and Chinese scientists who examined Microraptor’s fossilized feathers at the microscopic level. 

The iridescence breakthrough has an Ohio connection.  Dr. Matt Shawkey, a co-author of the study and associate professor of biology at the University of Akron, discovered that in the commonly iridescent feathers of modern birds, arrays of pigment-bearing organelles called melanosomes were uniquely narrow.  These same shapes were found in Microraptor melanosomes.

Want to learn more about this dinosaur?  The American Museum of Natural History will have a live video chat today (Friday, March 9) at 12:30pm to discuss this earliest record of iridescence.

For more information, pictures and videos visit this page on the American Museum of Natural History’s website.

(drawing of a Microraptor based on digital overlays of nine fossilized specimens, by AMNH/Mick Ellison. Image featured here on Science Daily)

Kindness Beats Selfishness

Insects, Musings & News

An article in the March 5 issue of The New Yorker got me thinking about human society.

Kin and Kind: A fight about the genetics of altruism by Jonah Lehrer describes the history of the inclusive fitness theory and the current dispute among evolutionary biologists on the origin of altruism.

It all started with E.O. Wilson, a biologist, author and expert on ants.  In 1975 he promoted the theory of kin selection to explain why altruistic individuals sacrifice themselves for their kin.  (Ants do this a lot!)  Natural selection says this shouldn’t work because their genes would die out but kin selection says they help their kin because it preserves the genes they share.  Survival through kinship was named inclusive fitness.

Over the years E.O.Wilson started to see holes in inclusive fitness.  In 2010 he and two mathematicians, Mark Nowak and Corina Tarnita, published an article in Nature that refuted it. 

Half The New Yorker article is about the resulting fight.  The other half is what caught my attention.

E.O.Wilson changed his mind because he learned more about ant behavior.  As it turns out, cooperation within a species doesn’t spring up easily.  When it happens to start within a group, it makes the group survive so well that they dominate other groups.  Further, cooperative species are so successful that they dominate others species.  Cooperation can start in any group.  It just happens that the groups are composed of kin.

This works because “Selfishness beats altruism within groups.  Altruistic groups beat selfish groups,”  as E.O. Wilson wrote in 2007.

The first principle has certainly been my experience.  Within a group, a selfish person pushes everyone else around.  We see it working for these individuals and our society advertises it in slogans that say “It’s all about you” and “Have it all.”   It doesn’t take much thinking to realize that you can’t have all of it if you’re sacrificing yourself.  So we’re encouraged to be selfish.

But wait.  The second principle is true too.  Selfish groups lose to altruistic ones.  Cooperation makes groups successful over rivals who fight among themselves.

It’s important not to lose sight of this.  Humans have been successful as a species because we help each other.  Selfishness is a disadvantage to society.  Rugged individuals fail in the face of disasters like last week’s tornadoes.  We can’t do everything alone, and we cannot expect society to thrive if we insist that everyone pull himself up by his own bootstraps.

I am happy to know that nature showed the way on this.

In my view kindness beats selfishness any day of the week!

(photo of leaf cutter ants, who are models of cooperation, from Wikimedia Commons. Click on the photo to see the original)