Archive for February, 2014

Feb 28 2014

Raccoon Makes A Mistake

Published by under Birds of Prey,Mammals

 

Late Wednesday night, February 26, at 11:15pm a raccoon climbed the bald eagles’ nesting tree at Hays while a noisy train rumbled by in the valley.  Mother Eagle was asleep but she heard the raccoon’s rustle and stood up to defend her three eggs.  As the mammal crested the nest edge she opened her wings and took a few steps toward it.  The raccoon turned and fled.

When you watch the encounter on this archived video from PixController you can see everything that’s going on, but the participants can’t.  The nest is lit at night by an infrared lamp mounted near the distant camera.  The camera can “see” the infrared light but we, the eagle, and the raccoon cannot.  On that overcast night the animals were dark shapes to each other.  I’m sure the raccoon was frightened to find an eagle!

Raccoons raid songbird nests because the songbirds are powerless to stop them but they avoid raptors because birds of prey will kill them.  Why was this raccoon attracted to a bald eagles’ nest?

Scott Kinsey gave us the hint on PABIRDS yesterday morning when he wrote:

It has been fun watching the Bald Eagle nest cam from Pittsburgh.  Finally got to see a feeding.  I think it was the male brought a fish for the female at 10:39am.  She had it done by about 10:47 and back on the eggs. Might have been a Gizzard Shad around eleven inches?

As Scott points out, the female eagle eats at the nest and though she sets the scraps aside she doesn’t take out the garbage.  Lots of smelly fish scraps are up there on the sticks.   The raccoon probably smelled the leftovers and came exploring for a meal.  When he realized his mistake he was out of there!

This surely isn’t the first time a raccoon has explored an eagles’ nest at night.  We just happened to see it because of the night vision camera.  He was lucky he didn’t make a fatal error.

Click here to see what’s happening right now at the eagles’ nest.

 

(video from the Pittsburgh Eaglecam by PixController)

p.s.  This episode points out another difference between bald eagles and peregrines.  Adult peregrines don’t eat at the nest during incubation and even when feeding nestlings they take out the garbage.

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Feb 27 2014

In As Little As Two Weeks

Published by under Peregrines

Peregrines, Titan and GG, mating in Lakewood, OH (photo by Chad+Chris Saladin)

Hold onto your hats!  Peregrine courtship is in full swing and in only two weeks we may see the first peregrine egg in Pittsburgh.

Chad+Chris Saladin captured this shot of Titan and GG mating in Lakewood, Ohio early this month.  Our peregrines are on the same schedule so you may be lucky to see this too, if you visit one of Pittsburgh’s nest sites.

  • University of Pittsburgh, Cathedral of Learning:  Dorothy and E2 are at home every day.  Their courtship includes fancy flying, food offerings from E2 to Dorothy, and mating, of course.  On Monday I watched E2 chase a distant peregrine out of his airspace.  He flew like an arrow, pumping his wings so the other peregrine could see him coming.  By the time he caught up to that bird he was a speck in my binoculars.  The intruder left quickly without a fight.
  • Gulf Tower:  The downtown peregrines have come home to the Gulf Tower!  Day after day they court and perch at the nestbox and the female digs in the gravel to prepare the nest.  We presume this pair is still Dori and Louie who last nested here in 2011.  Webcam snapshots of the female show Dori’s unique look including the color of her bands (haven’t read them yet) and her white shoulder “headlights.”  Sooner or later we’ll know for sure.  (Stay tuned for news of the falconcam.)
  • Tarentum Bridge:  Visit the Tarentum boat launch under the bridge to see this pair in courtship.  Leslie Ferree took pictures last Sunday and posted them on the Pittsburgh Falconuts Facebook page.
  • Monaca Bridges, Beaver County:  Last year this pair nested on an inaccessible railroad bridge over the Ohio River where Tim and Karena Johnson saw them mating last Sunday.  There are so many bridges to choose from that we can only hope they’ll return to Monaca-East-Rochester where they were easier to see and band.
  • Neville Island I-79 Bridge:  Anne Marie Bosnyak visited the area on February 15 and found both peregrines perched in a tree on the Glenfield side of the river.
  • Westinghouse Bridge:  Our #1 observer at this site, John English, has not been able to spend much time there so we have no recent sightings.  If you’re in the area, take a look.
  • McKees Rocks Bridge:  eBird reports that a peregrine was seen on Brunot’s Island (near the bridge) and Leslie Ferree saw one last Sunday.  If you’re looking for waterfowl near the penitentiary at Doerr Street or on the Mckees Rocks side of the Ohio, check the power towers for a peregrine.
  • Green Tree water tower:  Until yesterday morning the news here was “missing for many months” but yesterday Mary Jo Peden saw a peregrine perched on the water tower and Karena saw one (or both?) as well.  This is the easiest site to check if you’re in traffic heading to town on the Parkway West.

Right now is the very best time to watch peregrines because they want to be seen — by other peregrines.  Stop by any of these sites to check out their activity.  Keep alert for peregrines on bridges and other tall structures and you might find a new nest site.  Let me know what you see.

In as little as two weeks — March 13 — one of these nests may have an egg.

 

(photo by Chad+Chris Saladin. Click on the image to see the original.)

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Feb 26 2014

Bird Skeletons As Heavy As Mammals’

Published by under Bird Anatomy

Skeleton of wood grouse, Museum of Toulouse (photo from Wikimedia Commons)

A misconception that began with Galileo in 1683 was debunked four years ago but I’ve only just learned it now.  Perhaps this is news to you, too.

In the March 17, 2010 issue of Proceedings of The Royal Society B Biological Sciences, bat researcher, Elizabeth Dumont of the University of Massachusetts Amherst published her bird, bat and rodent bone density study and concluded:

Bird skeletons do not actually weigh any less than the skeletons of similarly sized mammals.  In other words, the skeleton of a two-ounce songbird weighs just as much as the skeleton of a two-ounce rodent.(1)

Elizabeth Dumont reached this conclusion by measuring the density of skulls (crania), upper arm bones (humeri) and thigh bones (femurs) of 20 families of perching birds, 11 families of rodents and 13 families of bats, all of them less than 400 grams.  The birds’ bones were the densest.  Then she ran the numbers on skeletal bone mass and volume.

She remarked, “The fact that bird bones are denser than bones in mammals not only makes them heavier for their size, but it may also make them stiffer and stronger. This is a new way to think about how bird skeletons are specialized for flying and solves the riddle of why bird skeletons appear so lightweight and are still relatively heavy.

“This has never been explained fully and so has never gotten into the textbooks. I’d like to see that change.”

So now we know.  Sorry, Galileo.

Read a (1)summary of the findings in Science Daily or the full article here in the Proceedings of The Royal Society B Biological Sciences.

 

(photo (flipped) of wood grouse skeleton at Museum of Toulouse by Didier Descouens, Creative Commons license, Wikimedia Commons. Click on the image to see the original. )

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Feb 25 2014

Bluebird Fight

Eastern bluebird fight (photo by Karen DeSantis)

We think of eastern bluebirds as gentle birds.  They seem to be poor fighters and often lose battles with house sparrows and starlings, so I was surprised to learn from Karen DeSantis that she witnessed two male eastern bluebirds in a long ferocious fight in late February a few years ago.

Karen described on PABIRDS how the fight began with chasing, then escalated into periodic knock downs and grim combat on the ground.  The males fluttered and rolled over a distance of about 30 feet while the female followed every move, twittering as she watched.  The birds were so oblivious that Karen was able to take photographs of the 15-minute battle.  Karen wrote, “It was the long duration of the fight that interested me the most.”

Though we might not realize it, these battles are consistent with bluebird behavior.

During the winter bluebirds flock in family groups and huddle together to stay warm.  In early spring their togetherness ends as the fathers eject their sons from the group before ‘Mom’ and ‘Dad’ nest again.

But the battle Karen witnessed was not a mild family squabble.  Its intensity indicates the guys were fighting over the lady.

Bluebirds are usually monogamous but about 20% of the young come from extra-pair copulations.  The males seem to know if their ladies’ eyes are wandering and guard their mates more closely if they’ve been messing around.  According to Birds of North America Online, “Experimental evaluations (Gowaty 1980) indicate male-male aggression most likely serves to protect threatened paternity. Males are aggressive to males usually in defense of paternity.”   These battles can be so intense that they end in the crippling or death of one of the birds.

Bluebirds may seem gentle but don’t mess with their mates!  Click on Karen’s photo above to watch a slideshow of the fight.

 

(photos by Karen DeSantis)

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Feb 24 2014

Maples, Midges And Mammals

Icy trail in Schenley Park, 22 Feb 2014 (photo by Kate St. John)

Spring is coming, slowly but surely.  Last weekend I took a walk in Schenley Park to see what was up.

On Saturday morning the snow was gone from the sidewalks and woods but Schenley’s gravel trails were sheets of ice.  I wore my ice cleats so I was able enjoy the sights without having to focus on my feet.  Three signs of spring attracted my attention: maples, midges and mammals.

The red maple branches look thick now because their buds are swelling …
Red maple buds, swollen in spring (photo by Kate St. John)

… and the sap is running.  I found a big hackberry whose sap was running so fast that it poured out of a limb wound and ran down the trunk in a rippling stream.  Warm days and cold nights are maple sugaring time.

Small, brown flying insects caught my eye.  Like the “flies” fisherman use to lure trout to the hook they’re impossible to identify and photograph, so I call them midges.  Their hatch in February won’t be eaten by warblers.

The mammals were active too, especially Schenley’s growing herd of the deer.   Hidden in plain sight I saw four deer browsing on saplings they hadn’t been able to reach under snow cover.  I whistled to attract their attention and three perked up their ears.

Deer in Schenley park, 222 Feb 2014 (photo by Kate St. John)

 

As usual I’m always surprised when my “Warm Day” February photographs look so brown.  The woods aren’t green yet but that’s just as well.  By mid-week the lows will be 8-10oF.

Maples, midges and mammals will wait a little longer for spring.

 

(photos by Kate St. John)

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Feb 23 2014

Light Pillars

Published by under Weather & Sky

Light pillars in Laramie, Wyoming (photo from Wikimedia Commons, Creative Commons license)

Last weekend on PABIRDS, Bill Drolsbaugh reported seeing light pillars at night in Sharon, PA.

He wrote:

Around 3 a.m.there were ice columns or pillars suspended above strong lights in Sharon Pa Quaker Steak and lube parking lots to the East [and]  NLMK steel plant on the horizon about a mile away to the s.w.    They are vertical refractions that can be seen in very cold temps and suspended fine snow above lights and have tall vertical rainbow-like qualities.  One of them was floating in front of my window about 20 ft out suspended in mid air like a Winter Wraith.

I’ve never seen light pillars so I looked for photos online and found this one taken in Laramie, Wyoming.

In the photo, the pillars look as if they shine straight up from each streetlight but as Les Cowley explains on his Atmospheric Optics website, they’re caused by reflections from millions of flat plate-like ice crystals between the light source and the observer.  This explains why Bill saw one floating 20 feet outside his window.

Click on Les’ diagram below to see it full size and read more about this optical phenomenon.

Diagram of light pillars by Les Cowley, Atmospheric Optics

 

As winter gives way to spring there will be fewer opportunities to witness these icy phenomena.  Given the choice I think we’d rather have warm weather than light pillars.

(photo of light pillars from Wikimedia Commons. Diagram of light pillars by Les Cowley at Atmospheric Optics.  Click on the images to see the originals.)

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Feb 22 2014

Athene

Burrowing owl near Goiânia, Goiás, Brazil, standing on one leg (photo from Wikimedia Commons)

The burrowing owl’s genus is named for Athena, goddess of wisdom.

In Brazil, this Athene cunicularia stood on one leg for his portrait.

Thinking big thoughts?

 

(This photograph was Picture of the Day at Wikimedia Commons on 19 February 2014.  Click on the image to see the original.)

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Feb 21 2014

She’s Back!

Published by under Peregrines

Dori at the Gulf Tower nest, 21 Feb 2014 (photo from the National Aviary falconcam at the Gulf Tower, Pittsburgh)

Happy news!  The downtown peregrines are so committed to the Gulf Tower site that the female roosted there last night.

The old falconcam still functions so I was able to pull snapshots.  This morning I gave it a look, and behold.  She’s back!

There are some wiring issues before the camera will be reliable but within the week the falconcam partners will restart video streaming and we’ll all be able to watch.  Thanks to the National Aviary, PixController, WildEarth, and Robert Peirce & Associates for making the camera possible.

Stay tuned!

p.s.  Yes, we know the camera cover is a bit dirty but we can’t go outside to clean it without disturbing the peregrines and possibly scaring them away from the Gulf Tower.  We’ll clean it on Banding Day.  :)

 

(photo from the National Aviary falconcam at Gulf Tower, Pittsburgh)

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Feb 20 2014

First Eagle Egg!

Spring is coming!  The bald eagles at Hays in the City of Pittsburgh laid their first egg yesterday at 4:45pm!

This the second year the eagles have nested in Hays but the first time we’ve been able to see inside the nest thanks to PixController’s streaming eaglecam and the PA Game Commission’s permission and site assistance.

The egg was immediately breaking news (no pun intended) at the Post-Gazette, Tribune Review, WPXI and KDKA to name just a few.

In this video of the egg’s first on-camera appearance notice the reactions of ‘Ma’ and ‘Pa’ eagle…

  • The video begins with the mother eagle standing over her egg, waiting for it to dry.  Her tail is spread and she’s holding her wings open to shelter the egg without touching it.
  • When the egg is dry, she gently rolls it with her beak and keeps her talons folded in as she steps near the egg. She is very careful.
  • Just before her mate arrives you can hear his “whee” call announcing his arrival.
  • Notice how much bigger the female is than her mate.  This size difference is normal in birds of prey.
  • Both eagle parents rearrange the sticks, mosses and grasses in the nest.  If you watch peregrine falconcams you’ll notice that peregrines don’t use sticks so there’s nothing to adjust. Watch closely and you’ll see peregrines rearrange the rocks.
  • Though the eagles are nesting on an extensive wooded hillside above the Monongahela River, the river banks hosts two active railroad tracks and a scrapyard.  That’s why you hear mechanical and industrial sounds on the camera.

You can watch the eaglecam at several websites. My two favorites are PixController and the National Aviary.  Click on a logo below to watch the Pittsburgh eaglecam.  PixController’s has a link to the video archives.

PixController logoNational Aviary logo

 

(video from Bill Powers at PixController)

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Feb 19 2014

Most Numerous Bird On Earth

Published by under Doves & Chickens

Bresse chickens (photo from Wikimedia Commons)

Surprise!  The chickens are back.(*)

In The Botany of Desire Michael Pollan remarks that the plants humans desire are more numerous and successful than those we don’t care about.  Apples and potatoes would be overlooked plants, found only in their native ranges in Asia and South America, if we didn’t like to eat them.

This is true of birds, too.  Chickens were domesticated about 8,000 years ago from the red junglefowl (Gallus gallus) of India and Southeast Asia. By now the domestic chicken comes in several colors, is barely able to fly, and is found around the globe.  “With a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird,” according to Wikipedia.

This is hard to imagine until you realize that 74% of ‘meat’ chickens and 68% of egg layers are raised by intensive farming methods, such as battery cages, where space per bird is minimized.  Fortunately there is pressure to legislatively and voluntarily stop inhumane practices. The EU, for example, outlawed battery cages in 2012.

Meanwhile urban farming is picking up, even in my own city neighborhood.  A couple of years ago I met a family of four hens who lived a few blocks from my home. Though kept for their egg-laying and treated as pets I was impressed by their “bird-ness” and their pecking order.  They were fascinating to watch.

Our desire for chickens and eggs insures these birds will always be the most numerous bird on earth.

 

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

(*) Peekaboo. This post appeared for two hours on January 31 and then disappeared until today.  Were you one of the few who saw it then?  Leave a comment if you did.

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