Category Archives: Birds of Prey

Eagle Excitement

Birds of Prey, Nesting & Courtship
Harmar Bald Eagle carrying nesting material (photo by Steve Gosser)
Harmar Bald Eagle carrying nesting material (photo by Steve Gosser)

11 March 2013:

Bald eagles are the talk of the town in Pittsburgh right now.

This month a nesting pair attracted attention at the Allegheny River in Harmar Township.  Steve Gosser photographed of one of them carrying nesting material yesterday.

Last month a bald eagle nest was confirmed at the Monongahela River in Pittsburgh’s Hays Woods.  Tom Moeller captured the pair in a morning conversation on March 5.

Bald eagle pair at Hays, Pittsburgh (photo by Tom Moeller)
Bald eagle pair at Hays, Pittsburgh, 2013 (photo by Tom Moeller)

Harmar and Hays join our first bald eagle nest along the Ohio River in Crescent Township (2012) to make it three nests on three rivers in Allegheny County.

The bald eagle’s return to Pittsburgh was a long time coming.  Their population crashed because of DDT and they’d been gone for decades because of water pollution. In the 1970s the U.S. banned DDT and passed the Clean Water Act.  In the meantime Allegheny County’s economy changed away from heavy industry.  The law and the economy together improved our water quality so that fish, the bald eagles’ favorite food, returned in good numbers.

The Hays Woods site in the City of Pittsburgh is a case in point. Eagles could not have nested there until a whole host of economic and environmental changes occurred.  I know the challenges the site has faced. It has taken 30 years.

  • Thirty years ago (1983) the Homestead steel mill closed due to economic issues.  Only a mile upstream from the eagles’ nest, that closure brought better air and water quality to Hays.  Fish increased in the Monongahela River.
  • Fifteen years ago (1998) LTV closed the Hazelwood coke plant across the river, another economic decision. Air quality improved and the river returned to its normal temperature.  Fish increased because the plant no longer dumped hot water into the Mon.
  • Almost immediately a new, larger coke plant was proposed for Hazelwood.  GASP and local residents worked to stop this new pollution source.  The coke plant was never built.
  • Ten years ago (2003) a developer planned to strip mine and valley-fill Hays Woods to build a race track and casino.  The Save Hays Woods Coalition formed to fight this plan and protect the 635-acre site.
  • Three years ago (2010) legal wrangling over the strip mine finally came to an end.
  • Today (2013) we have nesting bald eagles.
  • Update in 2020: The URA acquired the entire site on behalf of the City of Pittsburgh (2016). Hays Woods is going to be the City of Pittsburgh’s largest park.

Every bald eagle nest in western Pennsylvania has a story of recovery.  Thanks to the bittersweet end of heavy industry, dedicated environmental heroes, and the resilience of nature our national bird is back in town.

(photo of Harmar eagle with nesting material by Steve Gosser, photo of Hays eagle pair by Tom Moeller)

The Color Of Rust

Beyond Bounds, Birds of Prey

Ferruginous hawk (photo by Steve Valasek)

Here’s a big hawk that I’d love to see some day.  He’s a native of open country in the western U.S.

The ferruginous hawk comes in two color schemes:  a dark version (click here to see) and this beautiful light color.  All of them have rust-colored wings, back, and legs that give them their ferruginous name.

When they fly their shape is similar to red-tailed hawks but these birds are much larger.  Their scientific name, Buteo regalis, means “regal buteo.”

Here he is from below.  Look how his belly appears to be bordered by rust.  Those are actually his legs.

Ferruginous Hawk in flight (photo by Steve Valasek)

If I want to see this bird, I’ll have to travel west again.  Steve Valasek took these pictures in New Mexico.

 

(photos by Steve Valasek)

Target Bird

Beyond Bounds, Birds of Prey

White-tailed Kite (photo by William Parker)

When I registered at the San Diego Bird Festival I asked to exchange one of my pre-scheduled bird tours because I was desperate to see this Life Bird, the white-tailed kite.

The trip I wanted was full but David Kimball introduced me to local bird leader Susan Breisch who knows the county well.

Susan was so helpful!   She asked to see both my target bird list and my tour schedule, told me the likelihood of seeing my target birds, and suggested places to find them during my unscheduled time.

As usual some species are a challenge, others are surprisingly easy.  For instance…

I would love to see a mountain bluebird but they travel in flocks that move around a lot.  Their reported location one day may be different the next.  This behavior reminds me of the white-winged crossbills visiting Pittsburgh this winter whom I’ve been unable to find.  Hmmmm!

The ferruginous hawk is on my wish list, too, but it only visits the grasslands in winter and even then it’s not plentiful.  Again, you have to be at the right place at the right time and you have to get lucky.

However, white-tailed kites are easy!   They hang out in river valleys and can be found year-round in Rose Canyon where they nest.  In fact, I might even see one on a walk from my hotel.

Oh boy!

 

p.s.  The San Diego Bird Festival is great!  Excellent tours, helpful friendly people, unbeatable weather.  I highly recommend it!

 

(photo by William Parker)

The Size Of An Owl

Beyond Bounds, Birds of Prey

Speaking of owls, as I did on Thursday, here’s a portrait of one of the world’s largest owls, the Eurasian eagle-owl.

Bigger than a snowy owl he is slightly outweighed by the endangered Blakiston’s fish-owl of Asia and has a slightly shorter wing span than the great gray owl.

Despite these technicalities he is virtually the world’s largest owl.  With females weighing up to 9.3 pounds they are bigger than our great horned owl (up to 5.7 pounds), the eastern screech-owl (weighing up to 1/2 pound), and the northern saw-whet owl (weighing only as much as 1/3 pound).  The two smaller owls are dinner for the great horned owl.  Imagine what a Eurasian eagle-owl eats!

To get an idea of owl sizes, visit the National Aviary to see the eagle-owl and others up close.

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

Screech-owl Roost … and Nest?

Bird Behavior, Birds of Prey

Eastern screech-owl roosting in Owl Box #7 (image from PixController.com)

If you haven’t been watching PixController’s eastern screech-owl webcams you’ll want to start now.

Back in October when I first wrote about the webcams, eastern screech-owls were just starting their winter-roost season.  The birds hadn’t chosen preferred boxes and a squirrel was time-sharing in one of them.

Since then two owls have sorted out who roosts where.  They’re definitely aware of each other because they sometimes visit each others’ roosts or eat each others’ cached food.

This week they’ve been busy in Owl Boxes #2, #6 and #7.  On Tuesday night the owl nicknamed “Allie” caught and cached a mourning dove in Owl Box #2.  Last night she came back to eat it.  The motion detection cameras keep track of the owls so you don’t have to stay up all night.  Click here to see recent archives of owl activity.

Now that Winter is ending, things are about to get very interesting.  Eastern screech-owls nest in March.  Will they nest in one of the boxes?

Click here or on the image above to watch PixController’s Eastern Screech-owl Live Webcams.  You can also follow PixController on Facebook where Bill Powers posts the day’s best photos from his many webcam installations.

(image from PixController.com)

p.s. The owl looks white because of the infrared light.

Making The Snow Fly

Bird Behavior, Birds of Prey, Schenley Park

Red-tailed hawk in snow, Schenley Park (photo by Gregory Diskin)

If you have to sit outdoors in winter, you’re bound to get snowed on.

Last month during a particularly wet snowfall, Gregg Diskin found this red-tailed hawk perched in Schenley Park.  The bird was trying to stay warm and dry but it was a challenge.  His feathers were wet and his feet were getting cold.

See how he’s tucked one foot into his breast feathers?  It looks like he’s holding his coat closed.  Brrrrr!

Fortunately feathers are very good insulation.  You don’t realize how well they work until the hawk scratches his head.

Watch the snow fly!

Red-tailed hawk makes the snow fly (photo by Gregory Diskin)

(photos by Gregory Diskin)

Love Birds

Bird Behavior, Birds of Prey

Happy Valentine’s Day!

We’re not the only ones who celebrate love this month. February is raptor courtship time.

Last year on Valentine’s Day the Decorah Eagles nestcam captured the bald eagles, “Mom and Dad”, vocalizing and mating.

This year the eagles have built a second nest that’s closer to the fish hatchery and not on camera!   At this point it’s unclear which nest the eagles will use, but they’ll certainly disappoint their 60,500 followers if they choose the off camera site.

Pittsburgh’s “falconuts” experienced that disappointment a year ago when Dori and Louie chose a new nest site Downtown.  Unfortunately it looks like the peregrines aren’t coming home to the Gulf Tower so we’re going to have another year of off-camera love birds.

(video of the Decorah Eagles via YouTube)

Dogs To The Rescue

Bird Behavior, Birds of Prey
Max, a member of the University of Washington's Conservation Canines program, pauses after locating a northern spotted owl roosting in a tree in the Shasta-Trinity National Forest. (Credit: Jennifer Hartman/U of Washington)
Max, a dog who finds owls + an owl in the background at top left (photo by Jennifer Hartman, Univ of Washington)

6 February 2013

How do you survey a population of owls that are afraid to make noise?  Dogs to the rescue!

In 1990 northern spotted owls were listed as Threatened under the Endangered Species Act.  Since then their population has been surveyed year after year, but despite changes in logging practices northern spotted owls continue to decline 3.7% per year.

Part of the problem could be that some owls have fallen silent and are impossible to count.   The typical survey method is to play an owl recording and listen for the owl to respond.  But barred owls have infiltrated the old growth forest, displaced northern spotted owls, and sometimes killed them.  Some northern spotted owls would rather not respond when the tapes are played.  They don’t want to give themselves away.

So how do you count these owls?

Researchers at the University of Washington trained two dogs, Max and Shrek, to identify owl pellets by species!   Amazingly, the dogs can smell the difference in regurgitated mouse bones from a barred owl versus a northern spotted owl.

The team takes the dogs out for a spin in the forest.  They don’t use recordings at all.  The dogs sniff for pellets below owl roosts and are so good at identifying the species that they have a 30% better success rate at finding northern spotted owls than the recordings do.

Here’s Max triumphant.  See the northern spotted owl in the tree above him?

Good dog!

Read more about Max in the Science Daily press release.

(photo of  Max, a member of the University of Washington’s Conservation Canines program, by Jennifer Hartman, Univ of Washington)

Occupational Hazard

Bird Anatomy, Birds of Prey

Barred owl at Crooked Creek (photo by Steve Gosser)

How do owls turn their heads this far without killing themselves?

Trauma experts know that when humans turn their heads too far or too fast the arteries to the head are stretched or torn, cutting off the blood supply or producing blood clots that can kill.

Why doesn’t this happen to owls?  A team at Johns Hopkins decided to find out.

Led by medical illustrator Fabian de Kok-Mercado, they used imaging technology on barred, snowy and great horned owls who had died of natural causes. The researchers found four adaptations that make the owls’ wide range of movement possible:

  1. As in humans, the major arteries that feed the brain go through bony holes in the vertebrae but in owls these holes are 10 times larger than the arteries, allowing them to move within the hole without pinching.
  2. The owls’ vertebral artery enters the neck higher up than in other birds — in the 12th vertebrae rather than the 14th.  This provides more slack.
  3. When an owl turns its head the arteries at the base of the head balloon to take in more blood.  In humans the arteries get smaller and smaller.
  4. Owls also have small vessel connections between the carotid and vertebral arteries so if one path is blocked the other still works.

A simple turn of the head that’s so hazardous to us is all in a day’s work for an owl.

Read more about the study here in Science Daily.

(photo of a barred owl by Steve Gosser)

Does This Remind You Of Someone?

Bird Behavior, Birds of Prey

Peregrine fans, does this photo remind you of someone?

This scene is from Baringo Cliffs, Kenya where a lanner falcon attacked a Verreaux’s eagle and forced it to flip upside down to defend itself.

Lanners are about the size of peregrines and they hate eagles just as much as our peregrines do.

The photographer, Steve Garvie, describes it this way:
“A pair of Lanner Falcons were nesting at one end of the cliffs and this massive female Verreaux’s Eagle drifted into their airspace. The female Lanner took to the air and quickly gained height then she flapped twice twisted onto her side then plunged in a deep stoop striking the circling eagle on the back of the head. The female eagle got a sore one and as the Lanner approached again she flipped upside down and clearly indicated there would be no second chance!”

Half a world away on June 6, 2012, Pitt’s famous peregrine Dorothy saw a bald eagle approach her “cliff” at the Cathedral of Learning.  She too flapped a couple of times and then attacked.  The bald eagle flipped upside down but it didn’t matter.  Dorothy won.

Eagles, whether Verreaux’s or Bald, can’t fly upside down for long.  Though Garvie doesn’t say it, I’m sure the lanner drove the eagle away just as Dorothy did at Pitt.

It’s Guess Who Won with an African twist.

 

(photo by Steve Garvie on Wikimedia Commons. Click on the photo to see the original)