Monthly Archives: May 2014

Eagles And The Rats

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.)

On A Silk Foundation

Nesting & Courtship, Songbirds

Blue-gray gnatcatchers returned to Pennsylvania in April and set up shop immediately. As one of the earliest nesting insectivores they began courtship and site selection right away.

Nest-building is part of blue-gray courtship. Both the male and female build the nest and they make a lot of noise and exaggerated bows when they begin.  Meredith Lombard trained her camera on a nearby nest and filmed this pair’s efforts.  (Click on the image to watch the video on Meredith’s Flickr site.)

As you can see in the video, the nest is slightly expandable because it’s built on an elastic skeleton of spider webs and tentworm silk.  In the early stages of construction I’ve seen gnatcatchers chatter near decayed fall webworm tents, grab the silk and anchor it to their chosen site.  Later they poke the sides of the nest and stick in new bits of lichen and bark.  They also drag the silk upward to make the nest cup.

All of this activity makes them easy to find and watch.  Cowbirds watch them, too.  On Sunday I saw a pair of gnatcatchers harassing a female cowbird.  I hope they’re able to keep her away from their silky nest.

 

(video by Meredith Lombard)

Mystery At Green Tree

Peregrines

Peregrine flying to the Green Tree water tower (photo by Kate St. John)

Peregrine nesting season is not going well at the Green Tree water tower.  As far as we can tell, the pair has no nest.

In March we were hopeful when observers saw the peregrines actively courting.  On April 1 they were still mating when Shannon Thompson confirmed that the female is unbanded and the male has bands.  This is exactly opposite to the pair from last year when the female’s bands identified her as Dorothy and E2’s daughter from 2011.  (I wonder where she went.)

Since then the situation has gone downhill  I stopped by on April 26 and witnessed some strange interactions.

When I arrived I heard a peregrine wailing and saw one perched on an upper crossbar facing the central shelves (click here to see the shelves).   Soon this peregrine flew up, circled out, and returned. It was carrying prey.

Upon its return I heard wailing and kakking.  A second, unbanded peregrine flew out from a shelf under the water dome.  This one had been in a fight and was missing some primaries and secondaries on its right wing.  It flew to a mid-level crossbar, landed clumsily, and hunched over with its wings drooping on either side of the perch.  It wailed and wailed. Green tree female peregrine, hunched and wailing, 26 Apr 2014 (photo by Kate St. John)

The peregrine carrying prey landed far to the right. This one continued to wail but eventually scuttled over — still hunched — to receive her meal. The male flew away.  She continued to hunch and wobble before she began to eat.  She was so clumsy that I was fooled into thinking she could not stand, but I was wrong.

I stayed for 40 minutes, watching her eat and preen.  When she was done, she kakked halfheartedly and flew poorly in the strong wind to a perch on the other side of the water tower.  When I visited yesterday she was alone.

I haven’t seen a nest exchange at Green Tree but I have seen some very cranky behavior.  What is it all about?  I don’t know.  It’s a mystery.

 

p.s. The first photo shows the male flying in with prey. For a better look, click on that photo to see its full size original.

(photos by Kate St. John)

Leaf Out!

Schenley Park, Trees

Tulip tree leaves unfurling, 28 April 2014 (photo by Kate St. John)

Very soon southwestern Pennsylvania will reach the moment when most of the trees have leaves.  This usually happens around May 5.

Leaf out seems a bit delayed this year but it’s making progress.  On Monday (April 28) I found a tulip tree unfurling its leaves one by one.  By Thursday the same branch looked like this:

Tulip tree leaf-out, 1 May 2014 (photo by Kate St. John)

There’s probably another leaf inside that big bud, and then there will be a flower.

When will “Most of the Trees Have Leaves?”

For Schenley Park, I’ll let you know.

 

(photos by Kate St. John)

Later:  “Full Leaf” was late this year.  It didn’t happen until May 13 in Schenley Park.

Double-Teaming The Kids

Peregrines

Both peregrine parents feed five nestlings (snapshot from the National Aviary falconcam at Gulf Tower)
It’s been rainy this week so the Gulf Tower peregrine nestlings have been pretty demanding when it’s time to eat.  On Tuesday afternoon their parents double-teamed them for the midday feeding: Dori on the left, Louie on the right.

At one point the adults were in synch, bowing to grab a morsel, rising to put it in a little beak.

Both parents feed five peregrine nestlings (snapshot from the National Aviary falconcam at Gulf Tower)

 

And then Louie ran out of food and they all looked at mom.  Louie left shortly after this snapshot.

Both parents feed five peregrine nestlings (snapshot from the National Aviary falconcam at Gulf Tower)

 

In the photo above the chicks are 6-9 days old and growing their second down.  By this Sunday the oldest will be 14 days, their second down will be dense and long, and they’ll be ready to walk out of the scrape.

Watch their antics on the Gulf Tower falconcam.

 

(photos from the National Aviary falconcam at Gulf Tower)

Be A BirdSafe Volunteer

Books & Events

Wood thrush rescued Downtown, 28 April 2014 (photo by Matt Webb)

Spring migration is really heating up.  Every night the south wind brings new birds to town and with it the danger they’ll be injured or killed in Downtown Pittsburgh’s hall of mirrors.   How many birds are hurt?  This is the year to find out.

For six weeks BirdSafe Pittsburgh is discovering if and where migrating birds are injured Downtown.  I learned at the kickoff meeting that accidents don’t usually happen at the tops of skyscrapers.  Instead, most birds strike windows near street level when they become disoriented or confused by window reflections.

To assess the situation BirdSafe volunteers walk one of these eleven routes at dawn, looking for stunned or dead birds.  Stunned birds are rescued. All birds are counted.
BirdSafe Pittsburgh monitor routes (map from Matt Webb)

Participants have been pleasantly surprised at how beautiful and busy Downtown is at sunrise.  Terry Wiezorek didn’t find any hurt birds last week in the Cultural District when migration was slow, but she did find helpful maintenance people who will keep a lookout and let her know.   This week Monday’s increased migration tallied two dead birds and this rescued wood thrush that Matt Webb released at Allegheny Cemetery.  As Matt says, “One bird saved makes it all worth it!”

BirdSafe Pittsburgh needs more volunteers during this busy time.

Want to sample the project before you commit?  Meet the group at PPG Plaza on Monday mornings (next meeting: May 12) at 5:30am and walk a route with a BirdSafe volunteer.  It won’t cost you anything because on-street parking is FREE Downtown until 8:00am.

Contact Matt Webb at (412)53-AVIAN (412-532-8426) or birdsafepgh@gmail.com for more information.  He’d love to hear from you!

 

p.s. A big thank you to Terry for providing supplies for volunteers!

(BirdSafe Pittsburgh route map and rescued wood thrush photo by Matt Webb)