Archive for April, 2013

Apr 07 2013

First Native Flower

Published by under Phenology,Plants

Snow Trillium at Cedar Creek Park (photo by Dianne Machesney)

Yesterday I wrote about coltsfoot but it’s not the first native wildflower to bloom in western Pennsylvania.  That honor goes to snow trillium (Trillium nivale).

I looked for snow trillium last weekend at Raccoon Creek Wildflower Reserve and found the leaves but the deer had eaten all the flowers.    :(

Dianne and Bob Machesney found these blooming at Cedar Creek Park in Westmoreland County.

Thankfully there are fewer deer at Cedar Creek.

(photo by Dianne Machesney)

4 responses so far

Apr 07 2013

Major Migration In The Ohio Valley

Published by under Migration

NWS Central Great Lakes radar, 4/7/13, 4:18am (image from the National Weather Service)

The wind was finally from the south overnight.  This morning’s pre-dawn weather radar shows a little rain and a lot of birds.

The blue circles over the cities are radar locations picking up lots of small bodies flying north.  Yes, birds!

If you live in any of these blue circle zones, today would be a great day to go birding — unless it’s storming.

p.s.  There was not a lot of migration activity on the East Coast.  Their wind was probably unfavorable.

(radar image from the National Weather Service Central Great Lakes. Click on the image to see the most recent view.)

6 responses so far

Apr 06 2013

At Last!

Published by under Phenology,Plants

Coltsfoot blooming (photo by Marcy Cunkelman)

At last I’ve found coltsfoot blooming.  Spring is officially here.

Coltsfoot is an introduced plant that blooms earlier than most of our native wildflowers.  It’s not picky about habitat so you’ll find these dandelion-like flowers by the side of the road and in waste places.

When you see the flower you won’t see the leaves.  They’re hidden at the base of the plant right now but will grow into large colts’- foot-shaped leaves after the flowers are gone.

Coltsfoot blooming, from the side (photo by Marcy Cunkelman)

 

Normally I find coltsfoot blooming around March 25.  In last year’s hot weather it appeared on March 14.  You can see why I’m impatient.

At last!

(photos by Marcy Cunkelman)

4 responses so far

Apr 05 2013

How Can They Sit For So Long?

Dorothy asks E2 to get up so she can resume incubation (photo from the National Aviary falconcam at Univ. or Pittsburgh)

During courtship E2 is very active but now Dorothy has to plead with him to get up off the eggs.  Dorothy herself is able to sit for 12 hours in a snow storm.  How do they do it?

How do birds instantly switch gears from the frantic activity of courtship to sitting on eggs all the time?

They’re cued by hormones.  Here’s how:

  1. As day length increases after the winter solstice, a bird’s hypothalamus releases LHRH (luteinizing hormone releasing hormone).
  2. LHRH triggers the pituitary gland to release LH (luteinizing hormone).
  3. LH increases production of testosterone in males and progesterone in females.
  4. Testosterone triggers aggression, territoriality and sexual behavior.  It’s good at the start of breeding but doesn’t help raise a family.
  5. Progesterone is the “pregnancy hormone” that induces egg production.  It’s only needed for a short time since female birds are only ovulating and pregnant until they lay the eggs.
  6. On the day before incubation begins the hormones switch.  Prolactin, the hormone that promotes incubation behavior, rises sharply while the other hormones suddenly decrease.  In females, LH and progesterone drop off.  In males, testosterone has been dropping since egg laying began.  If the male shares incubation he has a sharp rise in prolactin, too.  On a graph this hormone switch looks like a sine curve.  There’s a moment where all these hormones are low, then prolactin takes off.

In peregrines, both parents have to be ready to incubate at the same time.  Their courtship rituals help get the couples’ hormones in synch.

This whole process may sound as if birds are at the mercy of their hormones but in every species reproduction is chemically tuned for success.  In humans for instance, progesterone and prolactin switch after delivery so that the mother’s body produces milk to feed the baby.  Individual animals whose hormones malfunction do not have live offspring.

So how do birds incubate so nicely?  In a word, prolactin.

 

(photo of Dorothy and E2 from the National Aviary falconcam at the University of Pittsburgh.  Today’s Tenth Page is inspired by page 448 of Ornithology by Frank B. Gill.)

10 responses so far

Apr 04 2013

This Is A Test

Published by under Quiz,Vocalizations

This is a test.  For the next two minutes this video will test your ability to identify birds by sound.  This is only a test.

Well, actually it’s a video of mockingbirds singing. Whose songs and calls are they imitating?

Use this quiz to get your ears in shape for birding by ear this spring.  At minimum you’ll remember the mockingbirds’ three-repeat song.

This is only a test.  If there had been an actual blue jay in the video you would have seen him.

(video by grcapro on YouTube)

5 responses so far

Apr 03 2013

Nature’s Mushroom Cloud

Sarychev Volcano, Matua Island, 12 June 2009 (photo from the International Space Station, NASA, via Wikimedia Commons)

Imagine seeing this outside your window!

On June 12, 2009 the International Space Station was flying over the Kuril Island chain in the northwestern Pacific when they witnessed the eruption of Sarychev peak, an active volcano on Russia’s Matua Island.

Because the eruption had just begun, brown ash and steam was still rising in a mushroom cloud that had punched a hole in the cloud cover above it.  Meanwhile, dark brown ash rolled low to the ground, probably a pyroclastic flow of hot gas and rock up to 1,850oF (1000oC) and traveling at 450 mph!

The ash had just begun to spread out in the sky (light brown at top left and right).  Soon commercial air traffic was diverted to avoid engine failure from this abrasive particulate in the upper atmosphere.

The astronauts were lucky to see this eruption as it began.

Nature makes an impressive mushroom cloud.

 

(photo from the International Space Station, NASA)

2 responses so far

Apr 02 2013

Cool Birds in The Crossley ID Raptor Guide

Published by under Books & Events

Crossley ID Guide: Raptors (image from Princeton University Press)

I just opened The Crossley ID Guide: Raptors and could barely put it down to tell you about it.

Birders and Hawk Watchers, you’re going to love this book.

The first half of this slim volume (286 pages) is devoted to color plates of raptors.  Crossley’s method is to build the plate with the bird’s typical habitat in the background.  Then he adds sharp in-focus photos of the birds taken from every possible angle, in a variety of lighting and at various distances.   The flood of photos provides enough images that you “get it.”   This is what the bird looks like in the field.

For solitary species this flood of birds is fictional.  You’ll never see that many of them in the same place at the same time unless you’re at a hawk watch — and that’s where Crossley’s mystery quiz plates are a real help!

Among the ID plates are double-page spreads of mixed species.  After I learned about zone-tailed hawks (I’ve never seen one) I tried the “Dark Raptors of the Southwest” quiz on pages 108-109.  It really helped to see them soaring at a distance near turkey vultures.  Wow! they are similar.

The second half of the book contains range maps and beautifully written species accounts by Jerry Ligouri (Hawks from Every Angle) and Brian Sullivan.  Here’s an excerpt from the peregrines’ Flight Style:  “Their powerful, fluid, whiplike, rolling wingbeats enable them to accelerate to high speeds in seconds.  They are steady in flight at all times!”

Peregrine fans will really love page 136, the first plate of peregrine falcons.  The background habitat is a city where peregrines breed today, the home of “SW” who hatched in Pittsburgh and is now Queen of the Terminal Tower.  You guessed it!  The setting is the skyline of Downtown Cleveland with SW’s home in the center of it all.

Click here for a sampler of The Crossley ID Guide: Raptors, including the urban peregrine page.  Click on the photo above to order the book from Princeton University Press.

p.s. There are 10 peregrines on page 136.  Can you find them all?  Did I miss one?

 

(book cover photo from Princeton University Press.  Click on the image for more information and to order the book)

5 responses so far

Apr 01 2013

Sounds Like Ducks

Published by under Insects, Fish, Frogs

Wood frog (photo by Marcy Cunkelman)

Last Saturday at Raccoon Wildflower Reserve I heard the sound of ducks in the woods but I wasn’t fooled.  I knew they were wood frogs.

For most of the year wood frogs (Rana sylvatica) keep a low profile.  In the summer they hide under leaves to avoid being eaten.  In the winter they’re literally frozen “frog-sicles” under the leaf litter, but in early spring they emerge for an orgy in the nearest vernal pond.

The male wood frogs float around and call to attract the females.  When the crowd really gets going they sound like ducks.  The first time I heard them I searched in vain for the flock of ducks making so much noise at the edge of a damp field.  Hah!  Wood frogs.  Click here to hear.

When the lady frogs arrive the orgy begins.  Multiple males grab a female and ride around on her back.  The pond becomes dotted with clumps of frogs.

After they mate the female wood frogs lay masses of eggs in big globs like this.

Wood frog eggs (photo by Marcy Cunkelman)

Then the orgy is over.  The adults disappear into the woods and the sound of ducks comes to an end.

Ironically, there’s a duck whose courtship call sounds like frogs:  the hooded merganser.

Nature is playing April Fools.

(photos by Marcy Cunkelman)

6 responses so far

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