Archive for the 'Nesting & Courtship' Category

Apr 22 2016

Names For Nestlings

Nestlings in 2009 (photo from National Aviary falconcam at Univ of Pittsburgh)

12-day-old peregrine nestlings, May 2009 (photo from National Aviary falconcam at Univ of Pittsburgh)

Perhaps we shouldn’t count our peregrines before they hatch but the chicks at the Hays bald eagle nest and Cornell’s red-tailed hawk nest made me think about nestling names.

When we see birds on camera we want them to have names.

Bald eagle chicks are named with the nest letter + a number that keeps increasing year after year.  At the Hays nest the names are H1, H2, H3, H4, H5, H6, etc.

At Cornell’s red-tailed hawk nest, Big Red and Ezra’s chicks are named with a letter that changes every year + a number.  The nest is now up to the letter G so the first two chicks were named G1 and G2 and together they’re called “the G’s.”

In the past we didn’t name peregrine nestlings until Banding Day but that led to misunderstandings and confusion so here’s the plan — similar to the bald eagle protocol.

The Cathedral of Learning nestlings will named with a nest letter that doesn’t change (C for Cathedral of Learning) + a number.  If we’d started this in 2009 the four nestlings above would be C1, C2, C3, C4.

Good luck figuring out who’s who!  Peregrine eggs all hatch within 24+ hours so the nestlings are the same size for a long time.  This only changes when the females become noticeably larger that the males. Males are 1/3 smaller.

15-day-old peregrine nestlings, May 2009 (photo from the National Aviary falconcam at Univ of Pittsburgh)

15-day-old peregrine nestlings, May 2009 (photo from the National Aviary falconcam at Univ of Pittsburgh)

 

When will the eggs hatch at Pitt?  I believe that real incubation did not begin until April 3 or 4.  Wild peregrines hatch their eggs in about 33 days.  (Incubator-raised eggs hatch sooner because of constant temperature without interruptions.)   So my prediction for Hatch Day at Pitt is approximately May 6.  …But I might be wrong…

Why isn’t the hatch date sooner?  After E2 died, Hope spent a long time away from the nest searching for a mate.  If she had heated the first three eggs to incubation temperature and then left them, her long absence would cause those embryos to fail.  At this point I believe she merely protected the three eggs until all four began incubation in early April.

 

(photos from the National Aviary falconcam at Univ of Pittsburgh, May 2009)

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Apr 20 2016

Red-Tail Eggs Hatching Soon!

Ezra the red-tailed hawk incubates three eggs at Cornell (screenshot from nestcam at Cornell Lab)

Ezra the red-tailed hawk incubates three eggs in Ithaca, NY (screenshot from nestcam via Cornell Lab)

In Ithaca, NY it’s been 38 days since Big Red, the red-tailed hawk, laid her first egg on March 13.  Today one of her three eggs has a pip.  Watch it hatch online!

Big Red and her mate Ezra nest on a light pole about 80 feet above an athletic field at Cornell University.  They’ve attracted an online crowd ever since Cornell Lab began hosting their nestcam in 2012 at Cornell Lab Birdcams.

Click here or on the screenshot above to watch Big Red, Ezra and their growing family.  Check out the Twitter feed on the right of their webpage for recent close-ups and videos from @CornellHawks.

Red-tailed hawk eggs hatch every other day so if you miss this first one there are two more eggs to watch.

Downy nestlings coming soon!

 

(screenshot from red-tailed hawk nestcam in Ithaca, NY via Cornell Lab)

 

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Apr 17 2016

Go See The Owls Soon

Great horned owl and owlet, Homestead Grays Bridge, 15 April 2016 (photo by Dana Nesiti)

Great horned owl and owlet, Homestead Grays Bridge, 15 April 2016 (photo by Dana Nesiti)

If you haven’t been to The Waterfront to see the great horned owl nest on the Homestead Grays Bridge, go soon!  The owlet is growing fast — as shown in these photos by Dana Nesiti on Friday, April 15.

Great horned owl and owlet, Homestead Grays Bridge, 15 April 2016 (photo by Dana Nesiti)

Great horned owl and owlet, Homestead Grays Bridge, 15 April 2016 (photo by Dana Nesiti)

 

Great horned owl and owlet, Homestead Grays Bridge, 15 April 2016 (photo by Dana Nesiti)

Great horned owl and owlet, Homestead Grays Bridge, 15 April 2016 (photo by Dana Nesiti)

 

Great horned owl and owlet, Homestead Grays Bridge, 15 April 2016 (photo by Dana Nesiti)

Great horned owl and owlet, Homestead Grays Bridge, 15 April 2016 (photo by Dana Nesiti)

The best viewing area is at the Three Rivers Heritage bike Trail to the right of the Red Robin restaurant at The Waterfront (175 E Waterfront Dr, Homestead, PA 15120).

Don’t miss your chance to see the owlet before he leaves the nest.

 

Thanks to Dana for sharing his photos.  See Dana’s great photos of the Hays bald eagles at his Eagles of Hays PA Facebook page.

(photos by Dana Nesiti)

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Apr 14 2016

The Don’t Walk Robin

American robin nesting on the Don't Walk sign (photo by Kate St. John)

American robin nesting on the Don’t Walk sign (photo by Kate St. John)

On Throw Back Thursday:

American robins have already begun to nest this month.  Back in April 2009 I noticed that one had chosen an unusual nest site on South Craig Street.

Can you see the bird incubating in front of the “Don’t Walk” sign?

Read more about her in this article called:  Don’t Walk!

 

(photo by Kate St. John)

2 responses so far

Apr 08 2016

Great Blue Heron Courtship

 

Let’s take a break from birds of prey. Here’s a story about another species.

Great blue herons (Ardea herodias) are returning to Pennsylvania and gathering at their rookeries to court and nest.

This video from Florida shows their elegant gestures and courtship rituals as they build their pair bond.

An added bonus on the video are the bird sounds in the background.  Listen and you’ll hear sandhill cranes, boat-tailed grackles and American coots.

 

(video by Filming Florida on YouTube)

 

6 responses so far

Apr 04 2016

Schenley Owl Nest Found

Great horned owl adult and one owlet, 2 Apr 2016, Anderson Bridge, Schenley Park (photo by Kate St. John)

Great horned owl adult and one owlet, 2 Apr 2016, Anderson Bridge, Schenley Park (photo by Kate St. John)

(If you subscribe to PABIRDS you saw this news over the weekend.)

After the great horned owl fledgling was rescued in Schenley Park on Tuesday March 29 and an adult was seen nearby on Thursday morning, I made it my mission to find the nest.  At first I came up empty.  There were no big stick nests in any of the hillside trees.

Then, late Friday afternoon I took another look at the underside of the Anderson Bridge.

Faintly through the trees I saw two owlets walking on a girder!

On Saturday I brought my scope and discovered that the “branching” owlets and their mother were quite visible from the Junction Hollow Bike Trail below the bridge.  Here are two (lousy!) photographs I took through my scope.

Above, mother owl and one owlet pose on the girder.  Below, the second owlet is perched just below the nest. Later he flew from girder to girder and landed near his mother.  The blue box highlights him in the washed-out photo.

Second owlet at Anderson Bridge great horned owl nest, Schenley Park,2 Apr 2016 (photo by Kate St. John)

Second owlet at Anderson Bridge great horned owl nest, Schenley Park, 2 Apr 2016 (photo by Kate St. John)

On Sunday I visited the trail again and Nathan Mallory used my scope to take this photo of the two owlets sleeping.  You can see their stick nest above them on the lattice.

Two great horned owlets sleeping near their nest under the Anderson Bridge (photo by Nathan Mallory)

Two great horned owlets sleeping near their nest under the Anderson Bridge, 3 Apr 2016 (photo by Nathan Mallory)

So there were three owlets in this nest. The first is in rehab.  The other two will probably fly soon.

 

 

p.s. As you can see, the Anderson Bridge is very rusty!  It will be completely replaced in a few years, after the Greenfield Bridge is done.

(photos by Kate St. John and Nathan Mallory)

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Apr 03 2016

Has Incubation Begun?

Terzo on four eggs at Pitt (photo from the National Aviary snapshot cam at Univ of Pittsburgh)

Terzo on four eggs at Pitt (photo from the National Aviary snapshot cam at Univ of Pittsburgh)

This morning Terzo kept four eggs warm at the Cathedral of Learning peregrine nest while Hope left to eat breakfast.

Here he is showing off the sharp contrast between his gray back and his black head and wing tips.  Hope’s feathers do not contrast as much.

Does this mean incubation has begun?  Terzo’s action is a good indication that this may be the first day of incubation, but the pair’s activities will tell the tale.  We’ll know for sure when they’re on the eggs nearly 24×7.

How long until the eggs hatch?

Incubation lasts about 33 days.  If today is the first day of incubation, watch for hatching around May 6.  (Note that hatch date predictions are never exact!)

 

(photo from the National Aviary snapshot camera at Univ of Pittsburgh)

 

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Apr 02 2016

Four Peregrine Eggs at Pitt!

Hope with 4 eggs at the Cathedral of Learning nest, 2 April 2016 (photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope with 4 eggs at the Cathedral of Learning nest, 2 April 2016 (photo from the National Aviary falconcam at Univ of Pittsburgh)

This afternoon at about 4:35pm, Hope laid her fourth egg of the season.

Her first three eggs were fathered by her deceased mate, E2, whose body was found on March 16.  This fourth egg arrived 15 days later and is undoubtedly fathered by her new mate Terzo.

Will she lay more eggs?  We don’t know.

Will she begin incubation now?  We’ll have to wait and see.

Only Hope knows the answers to these questions.

Stay tuned on the National Aviary falconcam at University of Pittsburgh to find out.

 

UPDATE:

Here’s a video captured by Peter Fullbrandt showing Hope laying the egg.  Skip to the 5:00 mark and you will see her breathing with her beak open for about 30 seconds.  When she raises her tail (at the 5:33 mark) it’s just after she’s laid the egg, though you cannot see it.   We waited for an hour for her to move off the eggs so we could count four.

 

(photo from the National Aviary snapshot camera at Univ of Pittsburgh; video capture by Peter Fullbrandt)

8 responses so far

Apr 01 2016

What About Egg #3?

Two nestlings watch as parent bald eagle returns to the Hays nest (photo from Hays eaglecam)

Two nestlings watch as parent bald eagle returns to the Hays nest (photo from Hays eaglecam)

 

By now it’s clear that the two nestlings in the Hays bald eagle nest are doing well but many of you wonder about the third unhatched egg.  What will happen to it?  Why hasn’t it hatched?

One unhatched egg is a fairly common occurrence in the nests of many birds.  Some eggs are not fertile, some have developmental issues. There are many reasons.  Birds often lay more eggs than actually hatch, perhaps as insurance against this rather common eventuality.

Among bald eagles, the need to brood the young for a week allows ample opportunity for remaining eggs to continue incubation and eventually hatch. While the adults brood the nestlings they can hear if an egg has a live bird in it because baby birds make peeping and hammering sounds inside the egg a day or more before hatching.  Eggs that aren’t going to hatch are silent.

What happens to unhatched eggs?  Birds are not emotional about them. When it’s obvious an egg won’t hatch, the family moves it around the nest for their convenience. In bald eagles’ nests it may eventually become buried under debris along with the remains of dinner.

What if it hatches now, more than a week late?  Here’s the answer from the Audubon Society of Western PA on their Bald Eagles of Western PA Facebook page on March 30, 9:39pm:

“We’ve gotten many questions about the last egg in the Hays nest. At this point there are no good options for what can happen with that egg. Perhaps the egg is just not viable and will not hatch. But if the egg should hatch (there is still a remote possibility) the newly-hatched eaglet would have a difficult time thriving. It would be more than a week younger than its siblings, meaning it would be much smaller and have a hard time competing for available food. While nobody likes to hear this, it is nature and if we didn’t have a webcam focused on the nest, we wouldn’t even know it was happening. All we can do now is wait and see how it plays out…and be thankful for the two vibrant eaglets that we do have in Hays.” — eagles.aswp.org

The text above gives you a hint.

Knowing bald eagle family life as I do, my hope is that the third egg never hatches.

 


UPDATE, 2 April 2016, 7:36am:  See below for a press release about Egg#3 from the Audubon Society of Western PA.

ASWP_logo

Audubon Society of Western Pennsylvania Statement on the Remaining Egg in the Hays, PA Bald Eagle Nest

For immediate release, April 2, 2016.

There is one unhatched egg remaining in the Hays, PA Bald Eagle nest. The egg has gone one week past the typical 35 day incubation period and at this time, the adult eagles are no longer actively incubating the egg. Audubon believes that the egg is not viable and will not hatch.

While we will never know for certain why this egg did not hatch, it’s possible that it was not fertile from the start. An infertile egg cannot develop into an eaglet and the egg would thus be deemed non-viable. It’s also possible that something went wrong developmentally within the egg after it was laid.

Across the state in Hanover, it appears that their local Bald Eagles also have an egg that is not going to hatch. We do not believe that there is any connection between the non-hatchings in Hanover and Hays—it’s nothing more than a coincidence. Last year, both sides of Pennsylvania had abnormally cold winters, which we believe was one of the factors that led to an unsuccessful breeding season for our Pittsburgh Bald Eagles. But in 2015, the Hanover Bald Eagles raised and fledged young, while facing the same cold temperatures. Before webcams were pointed on these nests, we did not know what was happening inside of them. Today we can see nature at work—both the good and the hard, sometimes uncomfortable reality of it.

The positive news is that the Hays Bald Eagles have two healthy and vibrant eaglets in their nest—eaglets that are approaching two weeks old and growing every day. We look forward to watching their continued growth and development, and eventual fledging from the nest in early summer. The Hays Bald Eagles have successfully hatched six eaglets: one in 2013, three in 2015, and two in 2016. The unhatched egg will eventually be broken through activity in the nest—parents and eaglets moving around. The egg, like the shells of the hatched eaglets, will eventually become invisible within the nest. An image of the female Hays Bald Eagle and two eaglets is attached.

Watch Pittsburgh’s eagles at eagles.aswp.org. For additional information on the Hays and Harmar Bald Eagles, please visit our Facebook page, www.facebook.com/pittsburgheagles, where daily updates on both nests are posted. The Harmar Bald Eagles’ first egg is expected to hatch on our around April 13.

 

(photo from Hays eaglecam)

p.s. Celebrate bald eagles this weekend at Audubon Society of Western PA’s Beechwood (Allegheny County) and Succop (Butler County) locations with a free “Eagle Egg” Hunt and other activities.

On Saturday, April 2 at Beechwood: Egg hunts at 11 am, 12 pm, and 1 pm – bring a bag to collect eggs! Parking is at Fairview Elementary School, 738 Dorseyville Road. Shuttles will bring visitors to Beechwood Farms Nature Reserve. Please allow time for the shuttle to transport you to the event. The Pennsylvania Game Commission and PixController will be onsite, as well as a local chicken expert who will bring baby chickens! There will also be games, crafts, and activities. Register today for Beechwood!

On Sunday, April 3 at Succop: Egg hunt begins at 12 pm – bring a bag to collect eggs! Then participate in eagle-themed games, crafts, and activities. Register today for Succop!

Or call (412) 963-6100 to sign up.

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Mar 31 2016

A Tale of Two Owls

Great horned owl on nest under the Homestead Grays Bridge, 27 March 2016 (photo by John English)

Great horned owl on nest under the Homestead Grays Bridge, 27 March 2016 (photo by John English)

For months we thought the old red-tailed hawks’ nest under the Homestead Grays Bridge was abandoned, but last Sunday John English discovered it is very much occupied — by a great horned owl.  John posted the photo above in the Duck Hollow Facebook group with this diagram of its location.

Location of nest under Homestead Grays Bridge (photo by John English)

Location of nest under Homestead Grays Bridge (formerly called the Homestead High Level Bridge) as seen from Red Robin at The Waterfront. Duck Hollow is on right, across the river (photo by John English)

Dana Nesiti (EaglesofHaysPA) stopped by yesterday and got this beautiful shot of the mother owl. In this species, only the females incubate and brood.  Father owl perches nearby during the day.

Great horned owl on nest under the Homestead Grays Bridge, 30 March 2016 (photo by Dana Nesiti)

Great horned owl on nest under the Homestead Grays Bridge, 30 March 2016 (photo by Dana Nesiti)

Dana watched for 45 minutes and was rewarded with a glimpse of the tiny owlet — the round white head at center-right of the nest.  I’m no expert but my guess is this owlet hatched 1-2 weeks ago.

Great horned owlet in nest under Homestead Grays Bridge, 30 March 2016 (photo by Dana Nesiti)

Great horned owlet in nest under Homestead Grays Bridge, 30 March 2016 (photo by Dana Nesiti)

 

Meanwhile, not far away….

At midday on Monday Cathy Bubash posted a comment on my blog that there was an injured owl on the road at Schenley Park’s Anderson Playground.  We traded email addresses and Cathy sent photos. Oh my!  It’s not an injured adult. It’s a fledgling great horned owl!

Great horned owl fledgling, Schenley Park, 29 Mar 2016 (photo by Cathy Bubash)

Great horned owl fledgling, Schenley Park, 29 Mar 2016 (photo by Cathy Bubash)

He’s old enough to fly, though he isn’t very good at it. He appears to be about 8 weeks old.

Great horned owl fledgling in flight, Schenley Park, 29 Mar 2016 (photo by Cathy Bubash)

Great horned owl fledgling in flight, Schenley Park, 29 Mar 2016 (photo by Cathy Bubash)

I visited the area at 4:30pm and found the owl safely perched on a hillside tree below the playground. His parents could find and feed him overnight … but where were they?

In all my visits to Schenley Park I’ve never encountered a great horned owl and never seen a nest.  I rechecked two abandoned red-tailed nests on nearby bridges. Nothing.

On Tuesday morning the owl was back on the asphalt at Anderson Playground so Public Works employees wisely called the PA Game Commission who collected the owl and delivered it to ARL Wildlife Center for evaluation.

Great horned owl fledgling rescued at Schenley Park by PGC, 29 March 2016 (photo by Kevin Wilford)

Great horned owl fledgling rescued at Schenley Park by PGC, 29 March 2016 (photo by Kevin Wilford)

It’s a good thing this owl was rescued.  He’s not injured but he is emaciated.  Did he have parents in Schenley Park?

Based on his age — two months older than our local owlets — I had a theory that he hatched in the South, perhaps the Carolinas, and was brought to Pittsburgh by someone who dumped him at the secluded end of the playground when he got too big.

But my theory was wrong! After publishing this blog I learned that a Public Works employee saw a great horned owl this morning at 6:45am near the Anderson Bridge.

In any case, while this owl fattens up he will have a good foster mom at ARL.  Martha the great horned owl will teach him everything he needs to know.

 

(photos by John English, Dana Nesiti, Cathy Bubash and Kevin Wilford)

Event:  This Sunday, April 3, 4:00-6:00pm, you can meet owls from the ARL Wildlife Center at their fundraiser at the Galleria of Mount Lebanon.  Click here to register.

p.s. Ravens are rare in the City of Pittsburgh but I saw a pair poke at the Homestead Grays Bridge nest on February 18.  They were agitated. Now I know why.  The owl was probably in the nest and just beginning incubation. Ravens hate great horned owls.

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