Archive for the 'Birds of Prey' Category

May 25 2014

Little Against Big

During the nesting season small songbirds chase large predators away from their eggs and young.  It’s a topsy-turvy time when the pecking order is reversed.

Sharon Leadbitter saw this in action last week at Allegheny Cemetery when a blue jay repeatedly bopped a red-tailed hawk on the head, trying to drive it away from his territory.

Eventually the blue jay was just too annoying ….

(video by Sharon Leadbitter)

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May 12 2014

Start Late, Finish Early

Gulf Tower chicks eat dinner, 6 May 2014 (photo from the National Aviary falconcam at Gulf Tower)

With two Pittsburgh raptor nests on camera we’re able to watch the nest cycle differences between peregrine falcons and bald eagles.  A big difference is timing: Peregrines nest later but they finish earlier.  We’re about to see that unfold.

Back in March it felt like peregrine egg laying was “late” because the Hays bald eagles had been incubating for two and a half weeks before Dori laid her first egg at the Gulf Tower.  In fact Dori was early, even by her own standards.  We just didn’t realize how much earlier bald eagles begin.

On May 6 (above) the peregrine nestlings were still developmentally behind the eaglets.  They weren’t very mobile and were still covered in fluffy white down with no apparent flight or facial feathers. They looked like babies.

On that same day the eaglets had been mobile for two weeks, had already grown some head and body feathers and had started to grow flight feathers.  They already looked like eagles (below).  PixController’s YouTube video of the bald eagles’ growth in April shows how they got to this stage.

Pittsburgh Hays eaglets, 6 May 2014 (photo from the Pittsburgh Hays eaglecam by PixController)

 

Despite their late start the Gulf Tower peregrine chicks are about to surpass the Hays bald eagles.  The table below shows they’ll depart their nest two+ weeks before the eaglets.  The peregrine fledglings will fly right away (departing a cliff nest requires flight) while the eaglets will likely flutter from their tree to lower vegetation or the ground where they may wait 1-3 weeks before flying again.

Keep in mind that fledge dates are just estimates.  Young birds learn to fly on their own schedule.

2014 NESTING LANDMARKS FOR THE GULF TOWER PEREGRINES AND HAYS BALD EAGLES:

____________ 1st Egg Hatch 1st Flight/Nest Departure
Gulf Peregrines 3/10 4/20-4/23 5/28-6/02 (5.5 wks)
Hays Eagles 2/20 3/28-4/02 6/16-6/28 (11-12 wks)

 

 

Start late, finish early.  Peregrines are faster than eagles in everything they do.

 

(photos from the National Aviary falconcam at Gulf Tower and the Pittsburgh Hays eaglecam via PixController)

 

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May 07 2014

Eagles And The Rats

Published by under Birds of Prey

Bald eagle at the Hays nest feeds a rat to her young (snapshot from Pittsburgh Hays Eaglecam by PixController)

Five weeks ago fans of the Hays bald eagle family were worried that the smallest eaglet would starve.  That didn’t happen.  There’s plenty of food and all three are thriving but a new and opposite fear has taken its place.  Just across the river one possible source of food is scheduled to be poisoned.  What if the eagle family eats a poisoned rat?

Bald eagles eat a lot of fish but they’re also opportunistic omnivores.  If a prey item is easy to catch they’ll eat it.  Eaglecam viewers have seen the family eat many fish, some birds and quite a few rats.

No one thought much about Rats As Food until a bankrupt business across the river in Hazelwood made the news.  The privately owned Pittsburgh Recycling Center closed its doors in January and walked away leaving behind stinking piles of garbage and lots of rats.  Over the winter the rats multiplied and overflowed into the neighborhood.  Nearby residents became so upset that they held a protest outside the warehouse last Friday.

On Monday the old warehouse was sold and the judge ordered the new owner to clean it up right away.  Hazelwood breathed a sigh of relief that the rats would be poisoned but the eagle watchers began to worry.  The Hays bald eagles are known to eat rats (see snapshot above).  If they eat a poisoned rat it will kill them.

U.S. Fish and Wildlife knows this all too well.  In 2009 they worked out a careful plan to kill the rats on an Aleutian island that had been a seabird nesting site 200 years ago.  They air-dropped poisoned bait cakes, the rats died, the seabirds came back to nest.  Only one thing went wrong.  They found the corpses of 43 bald eagles, 213 glacuous-winged gulls and a peregrine falcon.  Toxicology tests on several victims showed the project’s brodifacoum had killed them.  USFW’s Bruce Woods told Scientific American that with further study “we will attempt to figure out what we can do better.”

How likely is it that the Hays eagles will eat a rat from the poisoned warehouse?  We don’t know… but the warehouse is just a short flight away as seen by this snapshot from the eaglecam.  The red arrow points to the big white roof of the old warehouse.
View of rat-infested warehouse across the river from the Hays eagles' nest (photo from PixController)

The eagle watchers are so concerned that they’ve contacted the newspapers and television, started an online petition, and written letters to the Allegheny County Health Department and County Executive Rich Fitzgerald.  (The County Health Department is in charge of rat cleanup.)   These efforts have made everyone aware of the potential problem.

The rats are multiplying and have got to go.   To do it right without harming wildlife will take some ingenuity.  Fortunately, the pressure of the eagle watchers is making everyone put on their thinking caps.

 

p.s.  Peregrine fans:  Notice the obelisk on the horizon above the red arrow’s tail in the scene above.  That obelisk is the Cathedral of Learning, home to peregrine falcons Dorothy and E2.  As you can see, the eagles’ home is an easy commute for the peregrines.

(snapshots from PixController’s Pittsburgh Eaglecam.  Click on the eagle photo to watch the eaglecam.)

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Apr 12 2014

Holding His Own

Three healthy eaglets at Pittsburgh Hays bald eagle nest, 11 April 2014 (phot ofrom the Pittsburgh Hays eaglecam)

If you’ve been worried about the survival of Eaglet#3 at the Pittsburgh Hays bald eagle nest, you can ease your fears a bit.  Today the eaglets are 15, 13 and 10 days old.

On April 3 I described how competition among bald eagle siblings can cause the smallest eaglet to starve if food is scarce.   The good news is that the older they get, the better their chances for survival.

So far so good.  Eaglet #3 is active and growing and he’s getting fed.  Food is abundant. He’s holding his own.

The food supply is one more indication that Pittsburgh is a great place to raise a family.  But we knew that.  :)

 

(snapshot from the Pittsburgh Hays eaglecam.  Click on the image to watch the live stream)

Update:  Hmmmm. At 9:25am the three eaglets were very hungry and there was nothing to eat yet.  Eaglet#1 took a whack at Eaglet#3 who crouched with his face down to avoid attention.   Hmmmm. We shall see…

Eaglet#3 crouches to avoid another hit from Eaglet#1 (snapshot from the Pittsburgh Hays eaglecam)

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Apr 06 2014

Here’s How They Did It

You may be wondering how far the eaglecam is from the Pittsburgh Hays bald eagles’ nest and how it works out there in the woods.

This video from the Pennsylvania Game Commission shows how the eaglecam was installed last December and all the gear that makes it run.

I don’t know who climbed 75 feet up the camera tree but he was surely brave!

The man on the ground arranging the solar panels and batteries is Bill Powers of PixController.  He installed Pittsburgh’s two falconcams, too.

Many thanks, Bill, for all you do!

(YouTube video from the Pennsylvania Game Commission)

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Apr 03 2014

Three Eaglets … For Now

Third bald eagle egg hatches at the Hays nest (snapshot from the Pittsburgh Hays eaglecam)

Yesterday afternoon around 5:00pm the third and final egg hatched at the Pittsburgh Hays bald eagle nest.  This happened during rush hour so a lot of us missed it … or did you stay late at work to watch?

Click on the photo above to watch the eaglet emerge from his egg.

An hour later all the eaglets are visible as Mom feeds the oldest chick.

Her actions reminded me that we will soon see a characteristic of bald eagle family life that’s quite different from peregrines’ –  the tendency for the oldest eaglets to thrive and the youngest to die, sometimes killed by their siblings.

Bald eagle eggs hatch asynchronously so each new eaglet is two days smaller than the previous chick.  Bald eagle parents feed the chick that asks for food, and since the oldest is bigger and more active he’s fed more than his siblings.  Eagle chicks are aggressive toward their siblings and the parents don’t breakup the fights.  The third chick often starves.  Cornell’s Birds of North America Online describes it this way, referring to a study in Saskatchewan:

Hatching asynchrony and differential growth leads to differential mass in siblings, facilitating competition and fratricide. Sibling competition and mortality is greatest early in nestling period, when size differences are greatest. Third-hatched chicks in Saskatchewan nests received little food and usually starved.

This behavior is quite different from the peregrines’ lifestyle.  Peregrine falcon eggs hatch almost simultaneously so all the chicks are close in age and size.  The last chick may be smaller at first because he hatches two days later, but peregrine chicks are not aggressive and their parents make sure everyone eats at every feeding.   Mother peregrines “chup” to their babies to encourage them to stand up and be fed.  Click here see how effective (and cute) this is.

For now there are three eaglets at the Pittsburgh Hays eaglecam … but be prepared for the day when there might be only two.

 

(videos and snapshots from the Pittsburgh Hays eaglecam)

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Apr 01 2014

A Threat To Bald Eagle Nests

Aerial photo taken after a logging operation along the Rappahannock River cut an eagle nest tree. This forest block supported a bald eagle nest for ten years prior to the harvest. Photo by Bryan Watts. (linked from The Center for Conservation Biology)

 

The Internet is captivated by the Hays bald eagle family nesting on a wooded hillside in Pittsburgh.  Their nest is protected by the Pennsylvania Game Commission and worldwide media attention, but what happens to nests that aren’t so famous?  Here’s the story of an unexpected consequence of removing bald eagles from the federal endangered list.

For 40 years bald eagles were completely protected by the Endangered Species Act (ESA) and everyone understood not to harm them.  By 2007 the birds made such a great recovery that they were removed from the federal ESA listing. Fortunately they are still protected by a law of their own, the Bald and Golden Eagle Protection Act that protects eagles, their eggs and their nests.

The Center For Conservation Biology (CCB) in Williamsburg, Virginia monitors bald eagle nests in the Chesapeake Bay area where 75% of the nests are on private land.  Each spring they fly over the watershed twice: once to count occupied nests, later to count chicks.  Last month CCB reported what they’ve found after 6+ years without ESA protection:  a real increase in the number of eagle nest trees cut down.

Bald eagles use same the nest for many years so when CCB flies over the area in early March, they look for known as well as new nests.  Increasingly they find former nest trees are gone, cut down when an area is wiped out by a large logging operation like the one above.

Private landowners apparently don’t realize the Eagle Act protects the nest, so the well-publicized de-listing of the bald eagle has lead to an unintended consequence:  disregard for the eagles’ habitat and nest trees.  CCB points out that education of landowners is sorely needed.

Click on the photo above to read the full story at The Center For Conservation Biology.

 

(photo of a clearcut along the Rappahannock River in Virginia, linked from The Center For Conservation Biology blog.  Click on the image to read the article)

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Mar 31 2014

Four Celebrities

Pittsburgh's Hays Bald Eagle family, 30 March 2014, 2 parents, 2 chicks, 1 remaining egg (photo from the Hays eaglecam)

Yesterday was a big day for the Pittsburgh Hays bald eagle family.  Their second eaglet hatched just after dawn, and the whole family was featured on ABC World News with David Muir.

Above, both parents feed the chicks on Sunday afternoon.

Click here for the ABC news segment.

Their third and last egg is due to hatch April 1.

Watch them “live” on the eaglecam.

 

(photo from the Pittsburgh Hays eaglecam)

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Mar 29 2014

Eaglet’s Parents Celebrate

First eaglet of 2014 at Pittsburgh's Hays bald eagle nest, 28 March (snapshot from the eaglecam)

There he is, the first eaglet of 2014 at the Pittsburgh Hays bald eagle nest.  He’s hard to see because he matches the nest, hence the arrow.  The two remaining eggs and his discarded eggshell (closest to Dad’s beak) stand out.

This tiny gray ball of fluff emerged on a warm and windy afternoon, March 28, under his mother’s gaze.  As soon as he was dry she brooded him until Dad returned with food.

Click on the snapshot above to watch “Hays Parents Celebrate Hatch.”  Dad has brought a fish to share.  While Mom eats, Dad studies the eaglet. “Is he hungry?” Not yet, so Dad rearranges the nest.  Mom leaves on a well-deserved break and Dad settles down to brood the chick.

Bald eagles brood their nestlings during cold and inclement weather until they’re about four weeks old.   In the first week the brooding is almost constant because the nestlings can’t regulate their own body temperature.  This also serves the dual purpose of incubating the unhatched eggs while keeping the eaglet(s) warm.

The next egg is slated to hatch on March 31.  Watch the eaglecam to see.

 

p.s. Don’t forget you can also see the eagles in person today (March 29) on the Three Rivers Heritage Trail with the National Aviary’s Bob Mulvihill, 9:00am to noon.  Click here for more information.

(snapshot from Pittsburgh Hays Eaglecam, broadcast by WildEarth)

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Mar 28 2014

The Eaglet Has Landed!

The first eaglet of the season hatched today in the Pittsburgh’s Hays Bald Eagle nest at approximately 2:30pm.  In this YouTube video captured by PixController you can see the baby bird next to two eggs and his own eggshell.  Then mom comes over to help.

Watch him on camera here at PixController or here on the National Aviary website.

Media Attention:  He’s already a celebrity!

Festivities tomorrow!    March 29, 9:00am to noon, watch the nest at Hays — in person!

National Aviary Ornithologist Bob Mulvihill will be at the Hays Bald Eagle nest site tomorrow morning from 9 a.m. until noon with the spotting scope donated by Wild Birds Unlimited! Feel free to stop by for a really good look at the nest, maybe even catch a glimpse at what’s going on IN the nest!
Parking is available courtesy of Keystone Iron and Metal Co. in their employee parking lot at the end of Baldwin Road (see map), or use the address 4901 East Carson Street into your GPS!
The viewing site is a short distance from there: carefully cross the railroad tracks and turn left onto the trail. Bob will be about 200 feet down the trail with the spotting scope!
Click here for a map of how to get there.

Thanks to the PA Game Commission and PixController for bringing this eagle family up close.

 

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