Estimated 2015 Fledge Dates for Pittsburgh Area Peregrines

Peregrine falcon juvenile at U.S. Steel Tower (photo by Patti Mitsch)
Juvenile peregrine Downtown at U.S. Steel Tower, June 2014 (photo by Patti Mitsch)

Now that peregrine nestlings have been examined and aged in the Pittsburgh area, we can estimate when each site will make its first flight.

The fledging dates below are just estimates, calculated as the 39th day after hatch(*).  Young peregrines fly at 40-45 days old but the actual fledge date is up to the individual bird and sometimes the weather.  Males fly earlier than females because their lighter weight makes it easy to get airborne. In a nest with both male and female chicks the youngest females are alone at the nest for a day or two after the males have left.

In Pittsburgh, point-based Fledge Watches are set for a day or two before expected fledge through at least the second day after the last bird has flown.  Two days before flight it’s fun to watch the birds ledge-walk.  Two days after fledge, young peregrines have enough strength and flight ability to move faster and further than Fledge Watchers can navigate, especially in Downtown Pittsburgh.  At that point the official Fledge Watch dissolves while we wait for random reports of young peregrines peering in windows (nice to know) or accidents requiring rescue.

The table below shows the estimated dates.  Note that end dates always depend on activity at the site.

Nest Site Nestlings 39-day Estimated Fledge Date Watch for accidents until…
Neville Island I-79 Bridge 3 males, 1 female 6/10/2015 (Actual: Two left bridge on 6/6) 6/17 depending on activity
Downtown near corner of
Fifth & Grant
3 chicks, sex unknown, not banded 6/14/2015 (Actual: 1st flew on 6/11) 6/20 depending on activity
Cathedral of Learning at Pitt 1 chick, sex unknown,
development delayed by
5 days as of 5/29/15
6/18 or 6/23/15 due to unknown sex and
delayed development  (Actual: 6/21)
2 Days after the chick fledges
Westinghouse Bridge 2 chicks, sex unknown 7/3/15 7/10 depending on activity


Four of Pittsburgh’s eight peregrine nest sites have either no nesting activity or are a mystery this year.

  • Mystery: Monaca, Beaver County. Nest site is inaccessible on top of the big black P&LE Railroad bridge that crosses the Ohio River from Monaca to Beaver.
  • Mystery: McKees Rocks Bridge. Every year the peregrines’ nest is notoriously hard or impossible to find, even with a bucket truck.  This spring an adult pair was seen on May 24 and the pair “kakked” at a kayaker on the Alcosan side of the river on May 31.  It appears they have young but we have no idea where.
  • No nest:  Tarentum Bridge: This pair has not attempted to nest, perhaps because the male is young and still in juvenile plumage.
  • No peregrines: Green Tree water tower. Nest was attempted in 2013. No peregrines this year.

(photo of a fledgling at the U.S.Steel Tower, June 2014 by Patti Mitsch)

(*) The official first-flight age is 40 days after hatch, but can appear to be 39 days when a bird hatches overnight.

20 thoughts on “Estimated 2015 Fledge Dates for Pittsburgh Area Peregrines

  1. Hi Kate, we have moved into the city from south hills this year and can watch the downtown site. Do you want to send us details on where to look using email? My old email address was, which was on your list in the past.
    Thank you!

  2. Kate this is not related to fledging but do you have any idea why Fuzzy seems to spend so much time in corner of next box?

    1. Judy, it is normal for a peregrine chick to spend most of the day sleeping.

  3. Just wondering why there are nests where the eases were not banded….is this because it was impossible to get to them? Like Dori? No one can get to her nest apparently.

    1. Gindy, you are right. They are not banded if no one can reach the nest.

  4. I wish I lived in Pennsylvania so I could watch the fledges. I’m from Massachusetts so the camera will have to do. Thanks for the info on the dates Kate.

  5. So if one of Dori’s eyases falters during their fledge will they then be checked out and banded?

    1. Gindy, a falcon found on the street/ground will be placed high up on a building for it to start over. It will only be banded if the Game Commission officer doing the rescue has a permit to band peregrine falcons and the proper bands. This is such a specialized permit that few have it.

  6. Curious as to the ones that were not banded because of inaccessibility. How will they be tracked then? Is there another method?

    Thanks so much. I have learned so much this year about these creatures. They are fascinating.

    Jenn Long

    1. Jenn, peregrines are only banded in Pennsylvania because they are endangered here and we want to track them. In states where they have recovered they are no longer banded. That’s what will happen in Ohio beginning next year –> no bandings anymore.

  7. Hello Kate,
    Is there any way to position signage in the area of the Gulf Tower and Cathedral nests alerting folks to be on the lookout for fledglings in trouble.
    Thank you.

  8. Hi Kate! Do we know how far the Pitt baby might be able to see at this stage? Cool to see him intently looking/following things (bugs, windblown bits, flying “objects.”) Wondering what might be in his field of vision at this age. Thanks!

    1. Barbara, the chick can see his parents flying together over Schenley Plaza. I bet he finds it fascinating.

  9. Follow up questions on Silver’s ( = falcon’s ) “vision” posts :

    The eyeballs of owls, for example, are “fixed” in their sockets … so they have to move their whole head to “look around”- they can’t move just their eyeballs.
    Falcons ? Moving eyeballs OR fixed ?

    Also : “night vision” ?
    From what I read in Your past posts : falcons catch “food” in mid air = they don’t “ground hunt” . Since most “food” does NOT fly at night, I assume their night vision is not “the best”. However, in a non-urban settings, they would encounter night-intruders into their scrape – egg/baby thieves like snakes, racoons… .
    So, how is their night vision ?

    Again, thank you for indulging my curiosity.
    Thank You !

  10. kate this is not relate to the peregrine falcons. I was wondering if there has been anything done with the eaglet found from the Punxsatawney nest.

    1. Judy, I know nothing about the Punxsutawney eaglet because I have been so busy keeping up with peregrines.

  11. hi Kate, forgive me if I have the wrong bridge, but I thought you posted the photo of the juvie peregrine on the Westinghouse bridge ledge walking and assumed it would fledge soon thereafter, but have not seen another post concerning the outcome. I keep fearing that it was not a good outcome and that’s why nothing was said, but possibly it was just because nobody had a good vantage point since the RR won’t cooperate. Would appreciate an update, thanks.

    1. Robin, updates have been posted to the Pittsburgh Falconuts Facebook page (which is now a closed group). As of last evening all is well. The youngsters have probably flown but they are staying close to home so they can nag their parents for foods.

Leave a Reply

Your email address will not be published. Required fields are marked *