Apr 29 2013

What happened?

Published by at 7:20 am under Nesting & Courtship,Peregrines

Dorothy, 1 chick, 3 eggs, 28 April 2013 (photo from the National Aviary falconcam at Univ of Pittsburgh)

Since the news yesterday that one of the Pitt peregrine chicks died and that the three remaining eggs won’t hatch, many of you have asked questions in email, Facebook and blog comments.   Here are some answers, collected in one place.

After consistently raising three to five chicks every season, this year Dorothy has one healthy chick, one handicapped and now dead chick, and three unhatched eggs.  It isn’t the cold weather or poor parental care.  It’s because Dorothy’s getting old.   She’s 14.

Older female peregrines become less fertile.  History at other nest sites bears this out.  In the last two years of Tasha’s reign at the Gulf Tower she hatched 2 of 4 eggs and 2 of 5 eggs.  In 2010, in what was probably her 14th year, Tasha laid two eggs and then was displaced by Dori.   At the Terminal Tower in Cleveland, Tasha’s daughter SW is now 14 and has hatched only 2 of 4 eggs.  A similar pattern occurred at the Harrisburg site when their female aged a few years ago.

What will happen to Dorothy?   Dorothy is my very favorite peregrine in all the world.  I don’t like to think of it, but she is mortal just like the rest of us.  Frankly, it’s a good thing I can’t predict what will happen.  Time itself will tell.  Meanwhile I’m pleased as punch that she’s a mother again and has grandchildren, great-grandchildren and — if I only knew where — great-great grandchildren.  Go, Dorothy!

Brooding the dead chick:  After the handicapped chick died Dorothy drew it back into the nest and is brooding it along with the live chick and her 3 unhatched eggs.  I believe she knows the little one is dead but she’s doing what comes naturally — keeping everything warm until she’s absolutely sure.  I suspect E2 will remove it at some point when Dorothy is away as he did when one of the five chicks died in 2011.

What will happen to the unhatched eggs?  Dorothy will brood them along with Baby until he’s able to thermoregulate and moves off the nest.  Brooding lasts 8-12 days but can be shorter in warm weather.  When Baby is mobile, the parents will push aside the unhatched eggs where they will either desiccate or rot.  Last year’s unhatched egg rotted and smelled awful when it broke on WCO Beth Fife’s shirt during the banding.

Does the empty shell mean another egg has hatched?  No, this is an old shell that is swept from here to there by Dorothy’s tail.

Will the only chick do well?   If he’s healthy, yes.   Baby will get 100% attention from two very experienced parents.  Dorothy was an “only child” and is proof that only children can go far.

 

(photo from the National Aviary falconcam at University of Pittsburgh)

11 responses so far

11 Responses to “What happened?”

  1. Gail Hon 29 Apr 2013 at 8:40 am

    Dorothy is one of my favorites also (next to Beauty) and it will break my heart when her time comes, but as you said, she too is mortal.
    Thank you for all your hard work and information.

  2. Marylouon 29 Apr 2013 at 9:12 am

    Thank you for all this information. This is my first time to watch this exciting time in a Peregrine Falcon reproduction time of year. I was one of the people who was so sad at the failure of the little chick and the eggs. I love watching the little chicks and Dorthy taking care of them with E2. When I read that Dorthy was 14 years old I understood what happened. Even though I do not like it, I understand it. When People like your self explain how and why, you know this is how things happened in the wild.
    Thank you again

  3. Bobbyon 29 Apr 2013 at 10:46 am

    I am very sorry to hear this news. In a way, I have a vested interest in Dorothy. I am the “bobbytimewarp” Kate referred to in an earlier blog. I am the one who found Henry (and Dot) at Tower East. As mentioned, we in Cleveland are faced with a similar situation with our Pittsburgh gal, SW. I’m sure the remaining chick will be well attended to and I hope Dorothy hangs on as long as possible. Thanks for all the great info on this blog, Kate.

  4. Kate St. Johnon 29 Apr 2013 at 10:50 am

    Bobby, so good to hear from you! Thanks so much for watching out for our Henry. He makes is happy!

  5. Dan Brauningon 29 Apr 2013 at 12:37 pm

    Kate,
    Thanks for your thoughtful and insightful comments on the Cathedral Peregrine nest. I’m afraid you are right on the mark, she is past her prime. We don’t see the death of a newly hatched young very often, so that is quite telling. Of course, as the eternal optimist, maybe another of the remaining eggs will still hatch? Although peregrines normally hatch synchronously, hatching can span a few days, but I guess that window is closing quickly.

    I’m also practical, so we can predict that a younger female will push her out of that premier location. Eventually. And with that replacement, the population continues and grows. She has been a productive mother, having contributed much to the Peregrine Falcon recovery in the region.

  6. Karissaon 29 Apr 2013 at 12:52 pm

    Thanks for answering these questions. While I’m sad that the chick died and that the other eggs won’t likely hatch, I’m thrilled that this little chick will have the full attention of its parents. That sounds like an excellent evolutionary position to be in when it comes to broods and litters.

  7. Sue Vertosickon 29 Apr 2013 at 1:29 pm

    Thank you so much for the update. I just saw on the Post Gazette that work on the Green Tree water tank project (sandblast and paint) has been delayed due to the discovery of a nest of peregrine falcons. The nest is on the support beam that runs from the central water pipe to the tank. They posted the story about two hours ago.

  8. CarrolltonOhon 29 Apr 2013 at 1:39 pm

    Kate! I wonder if this is Magnum? Anyone around who can maybe get pics?

    http://www.post-gazette.com/stories/local/neighborhoods-south/peregrine-falcons-delay-green-tree-water-tank-project-685522/

  9. Kate St. Johnon 29 Apr 2013 at 2:27 pm

    Thanks for the water tower news. I’ve been working behind the scenes on this with those who reported these birds + the PA Game Commission to get just this outcome. News about this nest will be on the blog tomorrow!!!

  10. Kate St. Johnon 29 Apr 2013 at 2:28 pm

    CarolltonOH, the male is a juvenile. Watch the blog tomorrow for pictures.

  11. carolynon 02 May 2013 at 10:59 pm

    I am so sorry to hear the little one did not make it….and sorry the eggs are not hatching…and God Bless our Dorothy at 14 and still being a momma….I have such a soft spot in my heart for our furry and feathered friends….this saddens me but I will enjoy watching the baby grow….God Bless all who take care of them <3

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