Archive for June, 2011

Jun 21 2011

Power Sleep

Published by under Bird Behavior

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.)

6 responses so far

Jun 20 2011

I Was Just Leaving!

Sometimes I see the best birds when I'm looking for peregrines.

Last week I spent every lunch hour looking for the juvenile peregrines from Pitt.  I walked a big loop and checked St. Paul's Cathedral, Webster Hall, Heinz Chapel, the Cathedral of Learning and the tall buildings to the west but I could never find all four juveniles at the same time -- only two.

I'm not surprised.

By now the young peregrines fly well and are becoming independent.  They visit places far from the nest, pursue their parents whenever they show up, and play half-hearted aerial games with each other when they get bored. 

Dorothy and E2 are avoiding them by staying away from the Cathedral of Learning.  It's very quiet in Oakland.

On the other hand...

On Friday I saw a juvenile peregrine on St. Paul's steeple as I began my lunchtime loop.  The next time I looked he was gone.  The third time I glanced up a large raptor was flying toward the steeples. 

A red-tailed hawk?  No.  An immature bald eagle!

He circled up over Craig Street and by the time I passed St. Paul's he was very high up, almost a speck in the sky.  Then a smaller, faster, fiercer speck attacked him!

A highly skilled, very territorial peregrine falcon repeatedly dove on the eagle with talons bared.  The eagle was forced down and away to the east.  He looked as if he was saying, "Sorry!  I was just leaving!"

Good job, E2!  Still keeping the area safe for his offspring.

(photo by Steve Gosser)

21 responses so far

Jun 19 2011


Published by under Plants

Yesterday I found a patch of beautiful flowers with odd-looking balloons.

The balloons are "bladders" and the flowers are bladder campion (Silene vulgaris), an edible plant native to Europe that grows here like a weed. 

The bladders are actually the sepals, fused into a calyx.  The structure is so bulbous it looks as if it will prevent the flower from blooming but the tip of each bladder has five notches to guide the five white petals as they emerge. 

Strange, yet festive, flowers.

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

4 responses so far

Jun 18 2011

The Lightning Bugs Are Back

Published by under Insects, Fish, Frogs

Right on time, the lightning bugs are back in Pittsburgh.

Lightning bugs, or fireflies, are beetles that spend the majority of their lives as larvae.  We don't really notice them until they become adults and fly around flashing their luminescent abdomens.  In Pittsburgh they begin doing this in June(*).

One species, Photuris pennsylvanica, happens to be the State Insect of Pennsylvania.  Its larvae hibernate underground or under bark all winter and spend their days there too, only emerging at night to feed on soft-bodied insects, worms and tiny snails.   The larvae can glow, but they do not fly.

The adults are not as predatory because their primary goal is to find a mate which they do by flashing.

The females flash "come here" from a prominent perch while the males fly around looking for a responsive female -- and flashing their signals as well.  When they find each other, they mate.

For us, fireflies are pure joy.  They don't sting or bite and they create beautiful light shows on summer evenings.

I might not be wild about bugs but I do like fireflies!

p.s. If you want to see lightning bugs in your yard, don't use pesticides on your lawn and garden.

*p.p.s:  Readers in nearby counties have been seeing lightning bugs since Memorial Day.  I didn't notice them in the city until last night.  Is there a difference in timing or was I not paying attention?

(image from video on YouTube)

4 responses so far

Jun 17 2011

The View From Above

Published by under Peregrines

Even though she works in the U.S. Steel Building, Sharon Leadbitter cannot see the Gulf Tower peregrines during the nesting season -- not even on the web.  But after the young peregrines fledge, they fly and perch outside her window. 

Here are some of Sharon's pictures and videos of the Gulf Tower juveniles since June 8.  What a great view she has from above!

From a distance, Sharon can see the young peregrines perched on the Koppers Building roof edge.

Sometimes they sleep there. You can tell this one is young because it likes to sleep on its belly.

Food! A young peregrines shows her excitement over a food delivery to her favorite perch.

She hunches over her meal...

...but the excitement attracted her sibling and he wants to share it.

Hey! That was my dinner!

They're distracted.

Two young peregrines perch near a window. Who's in there?

And they find new napping zones.

Graduation! This juvenile is skilled enough to use Mom & Dad's perch.

Don't miss Sharon's videos:  Click here for her video of a juvenile exercising its wings and here for soaring.

(photos and videos by Sharon Leadbitter)

13 responses so far

Jun 16 2011

Safe In Cities

Published by under Nesting & Courtship

This spring I've been amazed at the diversity of birds nesting in the city.  Why are they here?  Isn't it more dangerous to nest in an urban area?

It turns out that city living offers some protection.

From 2004 through 2009, Ohio State University's School of Environment and Natural Resources conducted a study on nesting success in the cities, suburbs and forests of central Ohio.  The results were surprising.

In rural areas, as expected, the study showed that where the number of predators is high, nest survival is low. 

But in the city this correlation breaks down.  Even though there are more predators, nest survival has no relationship to their number.

Why is this?

"We think that the reason for the lack of connection between predator and prey within urban landscapes is due to the amount of food provided by humans in urban areas," said Amanda Rodewald, first author of the study and professor at OSU.

In other words, if the predators find something else to eat they don't raid nests.

So now I don't feel bad when the crows eat garbage.  It's far better than eating baby robins!

Read more about the OSU study in Science Daily.

(photo of a black redstart's nest by Michael Apel in Wikimedia Commons)

One response so far

Jun 15 2011

Don’t Scare Me!

Published by under Insects, Fish, Frogs

Butterflies and moths are often beautiful but their larval stage can look quite scary.

This scary appearance is intentional.  The spines and horns warn off predators that would otherwise eat them.  Unfortunately, this gets caterpillars into trouble with people sometimes.

I vividly remember a summer afternoon when I was about five years old.  I was playing on our back patio when I suddenly noticed a very large, very scary caterpillar.  I backed away from it, screaming and crying.  My dad came over to see what was the matter, promptly killed the caterpillar and comforted me.  "It's OK.  It's dead."

Since that time I've learned to appreciate nature, but I'm still not wild about insects.  I love butterflies and moths and would not kill their caterpillars (except, perhaps, gypsy moth caterpillars), but I prefer to keep a safe distance from the scary ones.

The scary parts are often harmless but without a caterpillar education I don't know when they aren't.  The hickory horned devil (Citheronia regalis), shown above, is perfectly harmless but you have to be sure of its identification before you pick it up.  Look at these photos!

Even with a caterpillar education, it's going to be a while before you see me doing this:

(This is a tobacco hornworm. For more photographs of caterpillars and moths, see Chuck Tague's photo galleries.)

(photos by Chuck Tague)

7 responses so far

Jun 14 2011

Best Bird in Smithfield

Today I'm back from a four-day weekend with my family in Smithfield, Virginia. 

While there I took long walks in Windsor Castle Park, a beautiful park with new boardwalks easily accessible from the historic downtown. 

The park has a variety of good habitat for birding: woodlands, fields and saltmarsh.    At low tide thousands of small crabs crawl the muddy banks of the saltmarsh, looking for food and becoming food themselves.  There's a heron rookery near the Cypress Creek overlook where the "baby" herons are now nearly as tall as their parents and quite loud when they're hungry.  I bet they eat crab for dinner.

I was happy to see many species that I never see in Pittsburgh including laughing gulls, royal terns and black vultures but the best birds by far were the summer tanagers.

The summer tanager (Piranga rubra) is a bird of southern forests.  They do nest in the southwestern corner of Pennsylvania but you have to go out of your way to find them.  At Smithfield I could hear them singing and a pair even came down to see me!

The male is all red and the female all yellow-green.  They have larger, longer beaks than scarlet tanagers and their head feathers stand up a little, giving them a Jimmy Durante look.  (Their back feathers don't stand up. The bird in this photo has a feather out of place.)

They're famous for eating bees and wasps and will even take the grubs out of wasp nests.  (Brave!)   They winter in Central and South America where they eat fruit as well. 

(photo taken in Manizales, Columbia by Julian Londono.  Image is from Wikimedia Commons licensed under Creative Commons Share Alike 2.0.  Click on the photo to see the original.)

3 responses so far

Jun 13 2011

More Peregrine Close-ups

Published by under Peregrines

A week ago Nancy Weixel was lucky to see three young peregrines lounging on a ledge at the Cathedral of Learning.  She just happened to have her camera.   Here's what she saw.

"Yellow" (female) standing next to "Red" (male).

"Red" is stepping out.

Begging.. though we can't hear her.

What do you think?  Was Nancy lucky?

(photos by Nancy Weixel)

17 responses so far

Jun 12 2011

An Ewt

Published by under Insects, Fish, Frogs

This is a juvenile eastern newt, also called a red-spotted newt. 

He began his life as an aquatic tadpole with gills, then graduated to this juvenile terrestrial stage.  After 2-3 years he'll become an adult, green with red spots, and go back to living in water. 

The juveniles are called red efts. 

The red is obvious, so obvious it makes you wonder why something this brightly colored is not eaten immediately but it's because he's orange.  To predators orange means Danger! Poison! and indeed red efts secrete poison from their skin when threatened or injured. 

What about the word eft?  Why is the name of a juvenile (eft) so different from the name of an adult (newt).

In Old English the name of this critter was pronounced eft or ewt.  Either name was OK.   Eventually "an ewt" became "a newt."   For example....

"She turned me into an ewt!

"A newt?" 

"I got better..."


(photo by Stan Kotala)

2 responses so far

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