Juvenile Female Makes Brief Intrusion at Pitt Nest

Juvenile female bows to Terzo at Pitt peregrine nest, 8 April 2016, 3:13pm (photo from National Aviary falconcam at Univ of Pittsburgh)
Juvenile female bows to Terzo at Pitt peregrine nest, 8 April 2016, 3:13pm (photo from National Aviary falconcam at Univ of Pittsburgh)

This afternoon webcam viewers were surprised to see a brown-colored falcon arrive at the Pitt peregrine nest and then bow and e-chup at Terzo as he was incubating.

Terzo was surprised, too.  He got up off the eggs and flew away leaving this juvenile, unbanded female to pause for a heartbeat … and then fly away as well.

Click here for the archived footage: Juvenile female visits the nest.

Juvenile unbanded female at Pitt peregrine nest, pausing before she leaves (photo from National Aviary falconcam at Univ of Pittsburgh)
Juvenile unbanded female at Pitt peregrine nest, pausing before she leaves (photo from National Aviary falconcam at Univ of Pittsburgh)

4 minutes later Terzo returned to the eggs.

40 minutes later Hope returned to incubate.

I’ve not had time to review all the footage but so far the archives show no sights or sounds of a fight with Hope.  Apparently Hope chased off this juvenile intruder.

For now, all is calm.


p.s. Thanks to Zack and sheba50 for pointing out this brief intrusion.  It was so brief that at first I couldn’t find any evidence of it.  I had to review a lot of footage to find it!

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

30 thoughts on “Juvenile Female Makes Brief Intrusion at Pitt Nest

    1. Janet, males do not chase females. The battles/chases are always male vs male, female vs female

  1. I can see it now…the young female says “Hi handsome, I’d like to incubate your eggs” and Terzo has this look on his face like “Oh no, you’re not Hope” and he rushes off to explain to Hope that it wasn’t his fault that this young chick is in their nest…..

  2. Wow…that’s interesting! Is it common for juveniles to visit an active nest? Is she looking for a mate or is she still too young? Her curiosity could get her into trouble!

    1. Denise, juveniles sometimes try to gain a territory. Usually they wait until they are adults.

  3. Heh, weird. I wonder if perhaps Terzo had originally paired with this female somewhere but upon seeing Hope’s advertisement for a mate dumped her for a more mature mate at a prime nesting site.

    This also reminds me of a question I’d been wanting to ask regarding the events surrounding Louie’s arrival at Gulf Tower in 2003. In the nesting history, you state that Tasha had already laid several eggs when another female came in and laid several of her own eggs in the same box before they both disappeared to fight for the territory. How was this intruder female able even get near the nest box let alone lay eggs when there was a resident female with eggs there?

    1. J, Tasha laid 2 eggs, then the fight occurred and Tasha lost to Dori. Then Dori laid 3 eggs and completed incubation without any fights.

    1. sheba50, No problem! I would never have noticed it at all if you hadn’t left me a message!

  4. First, Mary Ann… LOL!

    Kate, would this juvenile be one year old? I can’t remember how long they keep the brown feathers.

    She was a big girl!

    This is certainly a year of twists and turns….

    1. Anne Marie, yes she is one 1 year old. Quite dark!
      I can see one possibly-gray feather on the juvenile in the first photo. They take more than a year to molt into adult plumage. Next year at this time she’d be mostly gray-and-white with a few remaining brown feathers.

  5. I’ve missed a lot. What happened to hope’s original egg cluster (I know they are not viable) before E2 was killed? Are the current eggs all from Terzo?

  6. She looked big and healthy for a juvenile. She definitely looked bigger than Terzo, do you think she’s bigger than Hope?

    1. John, I don’t know the relative size. The good news is that Hope chased her off within 40 minutes and was uninterrupted yesterday.

  7. I was looking through your Peregrine FAQ’s and came across some older photos you had posted of how to tell the difference between Dori and Louie when they were at the Gulf Tower. In the photos Dori looks to be an extremely large female. That made me wonder about the juvenile falcon that paid a visit to Terzo at Pitt the other day. You said in a comment above that it was a 1 year old and it was unbanded. If I remember correctly, Dori and Louie’s babies from last year weren’t banded because no one knew where they were until they were about to fledge.

    The juvenile female looked really huge to me (just like Dori) compared to Terzo, so I was wondering if you thought that falcon could have possibly been one of Louie and Dori’s offspring from last year, especially given her size and the fact that she wasn’t banded.

    Thank you. I really enjoy reading your blog everyday!

    1. Carol, it is unlikely that the juvenile female is from Pittsburgh. When young peregrines disperse from their birthplace, the males travel short distances, the females travel far. This is shown repeatedly in tracking banded birds. For instance: Dori is from Akron OH, Louie is from Pittsburgh; Dorothy was from Milwaukee WI; E2 was from Pittsburgh; Hope is from Hopewell VA, Terzo is from Cincinnati OH. This differential dispersal is how they mix up the gene pool.

    2. One further thought on size of bird: The nestcam lens makes near images appear much larger than they are — kind of a fish-eye effect — so the juvenile, who never stepped to the back of the nest, would have looked much larger the entire time she was in camera.

  8. Kate, I thought that this was really interesting–I watched the video. The lives of these birds is so fascinating.
    I belong to a FB page on Mountaineering Ireland, and they just posted about a dead female and the suspicion that this was not an accident. Since my only acquaintance is with our “urban” falcons, I did not think about how the hikers and the falcons co-exist and how the hikers can keep an eye and protect them. And drones are a problem? I had not thought about that.

    Mountaineering Ireland
    1 hr ·
    Dead peregrine found in Dalkey Quarry
    Just a few days after a pair of peregrine falcons was reported to be nesting in the Central Buttress area of Dalkey Quarry, the female bird has been found dead. This will almost certainly result in the failure of the eggs to hatch.
    The National Parks & Wildlife Service is appealing to anybody who saw unusual activity in Dalkey Quarry, particularly below the signal tower, during the morning or around lunchtime on Saturday (9th April), to contact them.
    The peregrine falcon, which is protected under European and national legislation, is the fastest creature on the planet, and can dive at speeds of up to 200mph to strike its prey. As peregrines prey on smaller birds such as duck or pigeon, they have at times been subject to persecution.
    The cause of the bird’s death is being investigated by the National Parks & Wildlife Service (NPWS). While it is possible that the bird was poisoned, disturbance of wildlife by drones is also causing problems, especially during the breeding season.
    If you have any information which could possibly assist this investigation, please contact the NPWS District Conservation Officer, Ciaran Foley on ciaran.foley@ahg.gov.ie or (076) 100 2634.
    Climbers who experience a reaction from peregrines or nesting birds are asked to withdraw promptly so as to allow the birds the space to breed successfully. Mountaineering Ireland also appeals to people to keep a close eye out for suspicious activity at other peregrine falcon nest sites throughout the country.

    1. Mary, sadly in the U.K. and Ireland pigeon fanciers, gamekeepers, etc. shoot peregrine falcons. I’m guessing that’s why the death is under investigation and why they are asking hikers to report “suspicious” activity. The really sad part is that shooting birds of prey is such a problem over there that wild/remote nest sites are more vulnerable there than those in the U.S. … And yes it is interesting about drones. The PA Game Commission has just banned fronts on Game Lands.

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