Archive for the 'Musings & News' Category

Jan 02 2014

Beautiful Birds, 2013

What were your favorite birds of 2013?

If you’re from western Pennsylvania or northeastern Ohio, Steve Gosser’s six-minute video of favorites is likely to include a few of your own.

From the very public fight between a red-tailed hawk and a bald eagle to the elusive Virginia rail, Steve photographed all of them within a two-hour drive of Pittsburgh.

Beautiful!

(photos and video by Steve Gosser)

 

5 responses so far

Dec 23 2013

I Am Not Starving

Snowy owl in Wattsburg, PA (photo by Shawn Collins)

Joe Monahan of Boone County, Iowa generated a heated discussion on PABIRDS last week when he urged folks to save snowy owls by feeding them store-bought mice.  According to Joe the owls are starving: “The dead owls found here that were necropsied were found to be emaciated. Which is why I decided to start feeding the one remaining in our area.”

His idea raised ethical issues but Joe’s argument was that, based on those found dead, snowy owls are starving and ought to be fed.  The core of the discussion came down to: Were the dead owls evidence of a starving population?  Will feeding help or hurt?

Deciding the leading cause of death of a population — and what to do to help that population — based on those “found dead” is quite misleading.   If you visited Moore, Oklahoma on May 11 the majority of people found dead were killed by a tornado.  If we acted on that very real but skewed statistic we would move people out of Oklahoma because it’s a state known to have many tornadoes. However, the real leading causes of death in Oklahoma are heart disease and cancer, as elsewhere in the US.  Moving people away from Tornado Alley would not help and could hurt — upsetting some so much that they’d die prematurely (the autopsy would say it was heart disease).

Snowy owl studies by Paul Kerlinger, Norman Smith and colleagues show that as a population, wintering snowies are not starving at all.  Kerlinger’s study says: “Trauma-induced mortality was the cause of death in 64% of all cases, and starvation was implicated in just 14%, a figure the authors felt was likely inflated by several factors. Almost half of all snowy owls examined had moderate to heavy fat, and many of those lacking fat had suffered massive injuries.”   (Note that a bird that’s suffered massive injury starves because it cannot hunt.)  And, “of the 20 snowy owls Norman Smith satellite-tagged at Logan Airport, only four died – one from a plane strike and three from gunshot wounds.”  (People do hunt snowies up north.)

Will feeding help or hurt the birds?  Joe described his feeding method:  Holding a live mouse by the tail he would wait for the owl to fly toward him, then he toss the mouse when the owl was within 100 yards. Or he tossed a live mouse on a gravel road for the owl to retrieve.

Since the real leading cause of death in snowy owls is trauma, Joe’s well intentioned effort will probably backfire.  The owls will learn to trust humans and roads and may die prematurely, hit by a car or a bullet.

For everyone’s well being, learn more before you act.

“I am not starving,” says the snowy owl.

 

(photo by Shawn Collins)

p.s.  A big new snowy owl study has just been launched. Click here for details.

3 responses so far

Dec 19 2013

Same But Different

Steller's jay at Sandia Peak, New Mexico (photo by Steve Valasek)

Recent photos by Steve Valasek in New Mexico reminded me that western birds are often very similar to their eastern cousins.  Unlike the ecologically equivalent birds who live on different continents but have similar habitat requirements, these live on the same continent but have different habitat requirements.

Here are two western birds that fit the bill.

This Steller’s jay perched on a feeder in the Sandia Mountains is recognizably similar to our blue jay but he lives in evergreen forests in the mountainous West.  The blue jay prefers oak forests because he loves acorns.  Both jays like to visit bird feeders.

Below, the mountain chickadee also lives in dry evergreen forests in the Western mountains. He looks like a black-capped chickadee except for his white eyebrows.  The black-capped chickadee is far less picky about habitat and can be found in deciduous and evergreen forests, residential neighborhoods, weedy fields and cattail marshes.  Because of this the black-capped has a wider range.

Mountain chickadee, Sandia Mountains, New Mexico (photo by Steve Valasek)

 

And finally, a seed-eating generalist, this dark-eyed junco shows how different he looks in the West.  He’s different but the same.

Dark-eyed Junco, Embudito Canyon, New Mexico (photo by Steve Valasek)

Juncos breed in northern or mountain forests but can be found in a wide variety of habitats in winter.

When I first started birding juncos like this one were listed as a separate species, the Oregon junco.  Since then evidence has shown that the slate-colored junco of the East, the Oregon junco of the West, and the “white-winged” and “gray-headed” juncos are different races of the same species, now called the dark-eyed junco.

There is still much scientific discussion about the “lumping” of the junco.  Given enough time and isolation eastern and western juncos could become separate species and settle the question for us.

 

(photos by Steve Valasek)

One response so far

Dec 12 2013

Ancient Air

Published by under Musings & News

Spider and ant fossilized in amber (photo from WIkimedia Commons)

Amber is a rock that began as tree resin.  When it was resin it collected pollen, flecks of dirt, plants, small creatures, and other debris as it flowed from the tree. The amber above contains a spider, air bubbles, dirt and an ant, all preserved when the resin hardened.

Scientists are fascinated by amber because everything inside it is as old as the rock.  This year an international team led by Ralf Tappert of the University of Innsbruck analyzed carbon-12 and carbon-13 in present-day tree resin and amber dating all the way back to the Triassic period.  They chose amber for their chemical analysis because, as Tappert explains, “Compared to other organic matter, amber has the advantage that it remains chemically and isotopically almost unchanged over long periods of geological time.”

From 538 samples they calculated the concentration of oxygen in the atmosphere for 220 million years of the Earth’s history.  Surprisingly, they learned that the concentration in the early Cretaceous period was only 10-15% compared to 21% oxygen today.  The dinosaurs had less oxygen to breathe than we do!

This finding tossed out at least one theory about the dinosaurs, namely that their size was possible because they had so much more oxygen to breathe.  Oops!  They had less.

Click here to read more about the study at ABC Science (Australia).

Ancient air tells the tale.

 

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

One response so far

Dec 05 2013

Will You Be Underwater?

Published by under Musings & News

Earlier this year NOAA Coastal Services Center and NOAA’s climate.gov debuted an interactive mapping tool showing the effects of sea level rise on the US coast.  I learned about the Sea Level Rise Viewer in the video above.

Though we’re in no danger in Pittsburgh my family lives within 10 miles of the coasts of Virginia, Maryland, Florida, Massachusetts and New York so I was particularly interested in those places.  Alas, there is no map for Hampton Roads but the others are available.

Using the tool I zoomed in on a favorite birding location: Merritt Island National Wildlife Refuge off Titusville, Florida.

One foot of sea level rise will put some of Merritt Island underwater and surround the access road from Titusville.  Two feet will make it impossible to cross from Titusville and will bury Blackpoint Wildlife Drive. Here’s a screenshot of the two-foot rise.

Map of Merritt Island with two feet of sea level rise (screenshot from NOAA Climate Sea Level Mapping Tool)

Try the tool yourself.

  1. Watch the video above to see how it works.
  2. Click on this link to use the Beta version (my preferred version).
  3. A window will ask if you want to go back to the regular version. Stay on Beta by clicking the gray [Close] button at bottom right to make the window go away.
  4. Choose a place on the map using the controls at top right.  [Zoom to State or Territory] gets you there fast.
    Map controls for Sea Level Rise mapping tool (screenshot from NOAA Climate tool)
  5. Now use the controls on the left panel.  Move the blue sliding bar to make the water rise. (My red arrow below points to that bar.)  Watch what happens on the map.
    Map Controls screenshot, Sea Level Rise mapping tool (screenshot from NOAA Climate tool)

 

It’s amazing what a little rise in sea level can do.  Some day Merritt Island will disappear.

(video and screenshots from NOAA Coastal Services Center)

One response so far

Nov 13 2013

Give Back, Get Back

Chidham Point, West Sussex, UK (photo from Wikimedia Commons)

Breach an earthwork like the one above, give back land to the sea, and you’ll get fewer floods.

After Hurricanes Katrina and Sandy, U.S. emergency managers and town planners are discussing giving back land to the ocean as a way to protect still-viable coastal communities.  It’s a concept called “managed retreat,” a name that conjures loss and sometimes sparks defiance in those who live at the ocean’s door.

In the U.K. they’ve recently returned more than 450 acres to the sea by breaching an earthwork just five miles from this one at Chidham Point.  The locals are excited about it.  They expect the resulting salt marsh to increase tourism.  Here’s how:

At Medmerry on the south coast of England, shingle(*) sea walls were supposed to protect towns and undeveloped land but in recent years have proved inadequate.  Stronger storms and higher tides frequently flooded the low-lying communities, especially the caravan (campers) vacation parks.  Some sections of Selsey and Bracklesham Bay are below sea level.  It wasn’t working.

In 2011 the U.K.’s Environment Agency began a managed retreat project in West Sussex.  They built four miles of new sea walls up to a mile inland around the developed areas.  They also built drainage ditches and ponds, two parking lots for visitors, and 10km of bicycle paths and horse trails.  Then they breached the earthworks and gave land back to the sea.  The resulting salt marsh buffers the ocean’s rage.

It’s also great for wildlife.  Even while construction was underway migrating water birds stopped by to visit the growing new salt marsh.  Bird watching improved immediately and is expected to get even better in the months and years ahead.  The new salt marsh will be a birding tourist destination.

Give back to the sea and get back safety and tourism.  Compromise with Mother Nature is good.

Read more about this project and see a video here at the BBC News.

 

(photo of dike at Chidham Point, West Sussex, UK, located about 5 miles from Medmerry)

(*) The British word “shingle” means the sand, pebbles, cobbles and shell-pieces that make up the beach.

2 responses so far

Oct 14 2013

Before Columbus’ Day

Statue of Christopher Columbus by Frank Vittor, Schenley Park, Pittsburgh PA (photo by Piotrus via Wikimedia Commons)

When I learned American history in grade school, Christopher Columbus’ arrival on October 12, 1492 was Day One.  So little was said of the people and habitat that preceded his landing that it seemed nothing happened until he got here.  I learned that North America was an empty wilderness, barely inhabited.  By the time the English settlers arrived it was indeed empty, but it wasn’t like that before the first Columbus Day.

My perception of the western hemisphere changed forever when I read 1491: New Revelations of the Americas Before Columbus by Charles C. Mann (Knopf, 2005).  Examining scientific, historical and archaeological evidence, Mann describes what the continents were like before European infectious disease unwittingly changed everything in less than 200 years.  For example…

In 1491 the human population in the Americas was greater than that of Europe, the Central Mexican Plateau the most densely populated place on earth.  Unfortunately American Indians had no immunity to European diseases. Once the flame was lit their contact with each other and with escaped pigs from the Spanish expeditions fanned the plagues across the continents over and over again.  In the 150 years between First Contact (the first Columbus Day) and the first English settlers, 95% of the American Indian population died.

This emptied the hemisphere of its keystone species — humans.  Without the agricultural and hunting pressure of 100 million people the forest grew and other species took over.  For instance, Mann explains that passenger pigeons and bison were not numerous when American Indians ruled the continent but their populations exploded in the sudden the absence of humans.  Wow!

Sometimes while hiking I find a trace in the forest of a former homestead — a row of stones that bordered a field, an apple tree engulfed by weeds, a Norway spruce alone in the woods.  Nature took over the site but I can see the past because someone told me what to look for.  The settlers who arrived in the 1600′s found the continental equivalent of old field succession but no one was there to explain it.

Mann’s book gave me a window on the world before Columbus Day.  If you haven’t read 1491 I highly recommend it.

 

(statue of Christopher Columbus by Frank Vittor, erected by the Sons of Columbus in Schenley Park, Pittsburgh, in 1958. Photo from Wikimedia Commons. Click on the image to see the original)

One response so far

Oct 07 2013

On Caffeine

Spider webs with and without the spide on caffeine (photo from Wikipedia)

This blog is made possible by caffeine…  administered every morning in a 16 oz mug of coffee at 5:00am.  Boing!  I’m awake!   It works.  And it makes me happy.

Apparently it is not good for everyone.

According to Wikipedia, Swiss pharmacologist Peter Witt began testing different drugs on European garden spiders in 1948 because a zoologist friend of his, H. M. Peters, was annoyed that the spiders always wove their webs between 2:00am and 5:00am.  Dr. Peters wanted to study web building when he was awake, not when the spiders were.

Naturally it made sense to try caffeine.  Perhaps it would keep the spiders awake longer so that they’d “sleep in” and start weaving after dawn.

Not so!  Instead of time-shifting their web construction, caffeine made the spiders build whacky dysfunctional webs.

In 1995 NASA conducted a similar study and took photographs of the spider webs both before and after caffeine (above).

So much for Dr. Peters’ brilliant idea.  He was forced to study his subjects in the dark.  I’m sure he had to be on caffeine to do it.

Happy Monday.

(photos from Wikipedia. Click on the image to see the original)

5 responses so far

Oct 01 2013

Starling Story Problem

European starlings (photo by Bobby Greene)

When I was in grade school I hated Story Problems in math class — those word problems without formulas, just a bunch of facts to solve.

But life is full of stories.  I overcame my disgust, learned how to turn word problems into formulas, and became a math major.  Thus when I wrote about starling flocks last Friday I began to wonder…

How did the starling population increase from 100 birds released in Central Park in 1891 to 200 million (or more) in 2013?

Using information on their breeding habits and survival rate, I did some crude mathematics and came up with an answer.  First, the facts:

  • Starlings north of the 48th parallel produce only one brood per year, the rest produce two.  (To give you an idea of this location, the western U.S.-Canada border is at the 49th parallel.)
  • Female starlings typically lay 5 eggs per nest.
  • 50% – 80% of the eggs survive to the fledgling stage.
  • 20% of the fledglings survive to adulthood.
  • 60% of the adults survive each year.

(Warning!  If math makes your head spin, now’s the time to skip to the end.)

If we started with 100 starlings in Pittsburgh this spring, how many starlings would we have next spring?   To make it simple I made some big assumptions and did a lot of rounding.

  • 100 starlings = 50 nesting pairs
  • 50 pairs * 2 nests per year * 5 eggs per nest = 500 eggs this year
  • 50% to 80% of the eggs will fledge.  I used 65% * 500 eggs = 325 juvenile starlings in August.  I rounded this down to 300.
  • 100 adults + 300 juveniles = 400 starlings in August.   This is why we see so many starlings in the fall — and this doesn’t even include the migrants.
  • 60% of the adults survive to the next spring = 60% * 100 = 60 adults in March
  • 20% of the juvies survive the winter = 20% * 300 = 60 former juveniles in March
  • 60 adults + 60 of last year’s juveniles = 120 starlings in March

If I’m right (but I’m not) our starling population increases 400% in August, then winter trims it to an annual increase of 20% by March.

But 20% is too high.  Sixteen pairs survived from the 100 birds released in Central Park in 1891.  If their increase had been uniform it would resemble compound interest over 120 years (1891 to 2011) of about 14%.

(If you skipped the math, join me here.)

Interestingly, scientists estimated that the starling population boom in the western U.S. in the 1970′s was 16% per year, so I got close.

Fortunately the starling population seems to have stabilized so their annual increase is now — perhaps — zero.

How’s that for a story problem?

 

(photo by Bobby Greene)

3 responses so far

Sep 12 2013

No Food, No Water

Mount Desert Rock (photo by krzdweasel, Creative Commons license)

Twenty miles off the coast of Mount Desert Island is a tiny granite outcrop called Mount Desert Rock.  On a clear day you can see it with binoculars from the mountains of Acadia National Park. It looks like an improbable ship, taller than it is long.

Only 3.5 acres in size, Mount Desert Rock holds three buildings and a lighthouse just 17 feet above sea level. During winter storms and hurricanes the ocean washes over the island and punishes the buildings. The boathouse was swept away during Hurricane Bill in 2009. Isolated and exposed the Rock stands alone. Click here to see how small it is.

Map showing location of Mount Desert Rock (image from Wikimedia Commons)

Whale watching tours from Bar Harbor sometimes circle the Rock.  That’s how I’ve come close but never landed.  The Rock has no harbor so even those authorized to land can only do so when the sea is calm.

Lighthouse keepers and their families used to live year-round on the island, sheltering in the lighthouse during storms.  Since 1998 the College of the Atlantic has had whale and seal study crews posted there on temporary assignment, but they leave before a storm.

No matter who is stationed there, they must survive on food and water shipped from the mainland.  Rainwater is collected in a cistern under the keepers’ house but it’s undrinkable.  Nothing can grow there because the ocean washes away the topsoil in every storm.  And there is noise: The foghorn blares every 30 seconds.

When the weather is right, songbirds take a shortcut across the Gulf of Maine during fall migration from Nova Scotia to Maine.  From the whale watch boat I’ve seen ruby-throated hummingbirds and robins pumping their way past the Rock to Mt. Desert Island 20 miles away.  It’s scary to think they are over open water, sometimes fighting the wind, spending themselves to make landfall on the shores of Acadia — or else they will die.

Fly safe, little birds.  The Rock is no place to rest.  No food.  No water.

(photo by “krzdweasel” via Flickr, Creative Commons license.  Click on the image to see the original. Map from Wikipedia.)

2 responses so far

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