Oct 24 2014

Move Along, Move Along!

Published by under Crows, Ravens

Not everyone is as enthusiastic about winter crows as I am.  If you walk or park your car beneath the roosts you’re surely disgusted by the mess they make.  What to do? Move the crows.

Central New York state has lots of experience with crow wrangling.  At times Auburn has had 70,000 winter crows, more than two and a half times their human population of 28,000.  Years of trial and error have shown that killing crows doesn’t work but moving them does.

So now, every fall Central New York gets ready to move the crows to locations that aren’t so bothersome.  This August 2012 video shows a seminar in Baldwinsville, 20 miles northeast of Auburn … as the crow flies.

Move along, crows. Move along!

 

(YouTube from Central New York, WSTM)

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Oct 23 2014

TBT: Monster Of The Ohio

Published by under Insects, Fish, Frogs

Sam Hall and "Wally" the walleye, Ohio River, Oct 11, 2008

Sam Hall and “Wally” the walleye, Ohio River, Oct 11, 2008

What can you catch in the river in October?  The Monster of the Ohio.

On Throw-Back Thursday (TBT), here’s a fish story from October 2008.

 

(photo from Sam Hall)

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Oct 22 2014

An 80,000-Year-Old Tree

Published by under Plants

The world's oldest organism, Pando aspen (photo by USDA via Wikimedia Commons)

This may look like an aspen forest but it’s a single tree, 80,000 years old.

Last week at the Botanical Society of Western Pennsylvania we were wowed by the news that this stand of quaking aspen, covering 106 acres near Utah’s Fish Lake, is a single “tree.”  All the trunks are shoots from a single clonal root.

We learned this during Wil Taylor’s lecture on Jennings Prairie when he explained that aspen is threatening to take over Jennings.  DCNR burns or cuts the prairie to keep it open but aspen love that treatment.  They come back even stronger the next year with more shoots from the same root.  In fact, fire and low rainfall are probably the reason why this huge aspen is doing so well in Utah.

Discovered by Burton V. Barnes in 1968 and nicknamed The Trembling Giant, Barnes used morphological clues to determine this Populus tremuloides was from one clonal root.  In the 1990s Michael Grant studied it further and named it Pando.  DNA proves it to be one plant hosting 40,000 stems and weighing 13 million pounds.

Pando’s given age is 80,000 years but that’s the conservative estimate.  It may be as much as 1 million years old.  No one knows for sure.

 

(photo in the public domain via Wikimedia Commons. Click on the image to see the original)

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Oct 21 2014

Tuck Your Wings

Published by under Bird Behavior

Steppe eagle with backpack tracking device (photo by Graham Taylor, Creative Commons license)

Ever since we invented airplanes engineers have wondered how birds can withstand gusty turbulence that our light aircraft cannot.

To find out, researchers from Oxford University’s Department of Zoology fitted a captive steppe eagle (Aquila nipalensis) with a flight data recorder.   Steppe eagles are large, similar to our golden eagle, so the 75g black box was not a burden for ‘Cossack.’

As he flew at Brecon Beacons, Wales researchers filmed Cossack’s maneuvers, then tied the video to the recorded airspeed, acceleration, rotation rate, and GPS location.

Oxford reports, “An analysis of data from 45 flights revealed that in windy conditions the eagle would collapse its wings in response to particularly strong gusts rather than hold them out stiffly as an aircraft would. During these ‘wing tucks’, the bird’s wings were briefly (for around 0.35 seconds) folded beneath its body so that it was effectively ‘falling’. The results suggest that these ‘wing tucks’ may occur up to three times a minute in some conditions.”

Professor Graham Taylor said, “We think that, rather like the suspension on a car, birds use this technique to damp the potentially damaging jolting caused by turbulence.”

Have you seen large birds do this?  I have, but I didn’t realize what it was.  I know, for instance, that turkey vultures hate to flap but I’ve seen them crest a hill and suddenly tuck their wings.  Aha!  They probably encountered turbulence.

See raptors tuck their wings and, in November, golden eagles at the Allegheny Front Hawk Watch.  If you’d like a guided tour to the Allegheny Front sign up for the National Aviary’s November 1 bus trip.

For more on this study see the Journal of the Royal Society Interface.

 

(photo of ‘Cossack’ by Graham Taylor, Creative Commons license.  Click on the image to see the original article and image at Science Daily)

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Oct 20 2014

Planning Their Next Move

Published by under Crows, Ravens

A small assembly of crows (photo by Tom Harpel via Wikimiedia Commons)

Last month the crows had a meeting up north.

What are we going to do when it gets cold?  We can’t stay here.

Yup. These fields have grasshoppers now but they’ll be bare as soon as the frost hits.

Vince told me there are some nice places south of here in the Ohio Valley.  He recommended Wheeling Island and Pittsburgh.

I hear Pittsburgh’s great, especially the East End. Everyone had a great time last year.  Stay away from the Cathedral of Learning, though.  Peregrines live there.

OK, so we’ll go to Pittsburgh.

When do we leave?

In October.

In the past few days Anne-Marie, Julie and Anne have seen flocks of crows at dusk in Shadyside and Oakland.

The crows are back in town. Woo hoo!

 

(photo by Tom Harpel via Wikimedia Commons. Click on the image to see the original)

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Oct 19 2014

A Stellar Year For…

Published by under Plants

Honeysuckle fruits, October 2014 (photo by Kate St. John)

It’s a stellar year for bush honeysuckle berries.  The stems above were just a small part of the huge display at Wingfield Pines last week.

Can you count the berries?

Honeysuckle berries, October 2014 (photo by Kate St. John)

Birds like to eat honeysuckle fruit so these berries will disappear over the winter.

Too bad this plant is invasive.

 

(photos by Kate St. John)

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Oct 18 2014

Lots Of Robins

Published by under Migration

Flock of American rovins on the grass (photo by Marcy Cunkelman)

Have you tried counting robins lately?  This week it’s been a challenge.

Though it may seem pointless I usually count birds when I’m outdoors.  The reward comes later when I look back at the numbers.

Based on my counts I know that a first wave of migrating American robins came through Pittsburgh in September.  Their numbers dropped, but a second wave arrived last week to feast on the fruit in the city’s trees and bushes.

Unfortunately these birds are camouflaged by the autumn foliage.  Rust-and-brown robins match rust-and-brown leaves.  On walks in Brookline, Oakland and Squirrel Hill I counted 20, 50, 100 robins.  Why the round numbers?  I don’t know exactly how many there were.

All I know for sure is:  There are lots of robins right now.

 

(photo by Marcy Cunkleman)

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Oct 17 2014

Who Owns The Sky?

Last week’s sensational bird video showed a red-tailed hawk attacking a personal drone in Cambridge, Massachusetts (above). The drone lost.

Drones are popular because they’re easy to fly and come with onboard videocams.  Open the box, assemble a few pieces, turn on the camera, and fly it up and into … trouble, if you aren’t careful.  Novices don’t realize who owns the sky.

When Amazon Prime announced plans last December to deliver packages using drones it sounded simple but the initial hype failed to mention the regulatory, mechanical and natural hurdles.   Blog posts at Slate and The Atlantic immediately set the record straight.

At Slate Konstantin Kakaes explained how unreliable drones are right now and how much the FAA controls the airspace.  Drone pilots looking for killer video ignore the law to their peril and have been arrested.

The next day Nicholas Lund at Slate and Megan Garber at The Atlantic were quick to mention the bird factor.  Click on The Atlantic link to see five videos of angry bird attacks.

The FAA limits personal drones to a 400-foot ceiling — that’s below the 30th floor of the Cathedral of Learning — but birds of prey limit flying threats to a much lower level than that.  Red-tailed hawks near the Cathedral of Learning are frequently reminded that peregrines own the airspace above the treetops.  Drone pilots could learn a valuable lesson from a bald eagle who strayed into Dorothy’s zone.

Birds have owned the sky for 160 million years.

Take that you pesky airplane!

 

(drone video by Christopher Schmidt on YouTube. Click on Christopher’s link to read more about the hawk video)

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Oct 16 2014

Woodpecker Toes

Published by under Bird Anatomy

Red-bellied woodpecker's toes, on banding day (photo by Kate St. John)

Here’s a closeup of woodpecker toes from banding day at Marcy Cunkelman’s last July.

Look at the direction of the toenails and you can you tell they belong to a woodpecker.  Two claws curl forward, two curl back.

Woodpeckers have zygodactyl feet that help them cling to tree trunks.

The other foot from the same red-bellied woodpecker shows his toes open — two forward, two back.  Notice that the toes aren’t all the same length.  The little toe is Toe #1, the hallux.

Red-bellied woodpeckertoes, foot open on banding day (photo by Kate St. John)

 

Most perching birds have three toes forward while the hallux points back: anisodactyl feet.  (You might recognize these toes from yesterday’s Swainson’s thrush photo.)

Feet of Swainson's thrush (cropped photo from Wikimedia Commons)

Anisodactyl is the most common form but there are four other arrangements of birds’ toes.  Read more and see a diagram at this blog post from 2010.

 

(woodpecker photos by Kate St. John. Swainson’s thrush feet are cropped from a photo on Wikimedia Commons. Click on the Swainson’s toes to see the original photo)

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Oct 15 2014

Hybrid Migration

Swainson's Thrush (photo by Matt Reinbold, Bismarck ND, from Wikimedia Commons)

If you’re a Swainson’s thrush of mixed parentage you’ll probably pick a bad migration route.  It’s in your genes.

In eastern North America we see only one subspecies of Swainson’s thrush, the olive-backed (above), but in British Columbia there are two.  The russet-backed subspecies breeds along the Pacific coast and follows the coast to spend the winter in Mexico and Costa Rica.  The olive-backed subspecies breeds in the interior and migrates across the continent and the Gulf of Mexico to winter in South America.

Where their breeding ranges meet the thrushes pair up without regard to these distinctions.  Their hybrid offspring inherit a mixture from their parents, including mixed coloration.

Kira Delmore at the University of British Columbia wondered if the hybridization extended to their migration routes so she tagged hybrid Swainson’s thrushes with light-level geolocators to track their routes.

The data proved that their migration routes are inherited and that those of mixed parentage inherit a blend.  While each parent would have followed the Pacific coast or a safe route across the continent, the hybrids chose novel and dangerous compromises between the two paths.

“Instead of taking well-trodden paths through fertile areas, these birds choose to scale mountains and cross deserts,” said Delmore.

The dangerous routes probably cause more hybrids to die on migration than their pure counterparts, thus keeping the subspecies distinct.  Says Delmore, “The self-destructive behavior of hybrids could be helping to maintain the great diversity of songbirds we enjoy.”

Read more about this study here at Science Daily.

 

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

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