More on Incubation & Hatching

Mariah and eggs

Despite our unofficial motto at Imprints, specto subitus (expect the unexpected), it seems pretty safe to say that Mariah is done laying eggs for this year. Quite naturally we’ve received a lot of questions from our viewers asking when we can expect the eggs to hatch.

We can’t give an exact date (falcon egg hatching prediction is far from an exact science) but in general, the eggs should hatch about 33 days after incubation begins. Since Mariah laid her final egg on April 7 and began incubating a few days before that, we expect to see the eggs start to hatch around the second week of May. That means Mariah’s new family should all be out of their shells by Mothers Day.

The hatching process usually takes a couple of days, though it can go longer than three days (72 hours) in some cases. The eyas uses an egg tooth to break through the egg in a process called pipping. The hatching eyas uses its egg tooth like a chisel. First it pierces a membrane-like pouch at one end of the egg. The pouch holds air that the eyas uses to breathe while it finishes punching a hole through the shell. During pipping, the eyas turns and chisels, turns and chisels, until eventually it cuts off one end of the shell. Between bouts of pipping the eyas will rest, and it may vocalize while it’s pipping, especially if Mariah or Kaver are making their ee-chupping sounds.

The final round of pipping takes between 15 minutes and an hour. Because Mariah didn’t start incubating until the third egg had been laid, all four should hatch close together. In clutches of four, all the eggs usually hatch within two days. This is called synchronous hatching. Because of synchronous hatching all the eyases will be about the same size, and therefore about equally able to compete for Mariah and Kaver’s attention, which means they’re all likely to get fed enough to grow into healthy fledglings. We’ll talk more about the eyases’ early development in another article.

-Jess

20 Responses to “More on Incubation & Hatching”

  1. Jane says:

    Thank you so much, Jess, for informing us about the upcoming hatching time. My class of 4th, 5th, and 6th grade students have been following this sight for several weeks. Can you give me any information about where to send suggestions for names for the falcons after they hatch? My class has been discussing possiblities for them. This year’s website on Mariah and Kaver is fantastic. It’s very kid friendly and informative. I appreciate it greatly!

  2. Ian Gonzalez says:

    Thank you for telling me things about the falcons. I learned a lot of things I never new. My brother learnd a lot to. Thank you for all the information.

  3. james says:

    The other night we heard the fireworks going off at the end of a game at Frontier fieild and I started to think about Mariah and Kaver.Do the fireworks at Frontier have an effect on the nesting birds?

  4. Diane from Parma says:

    I’ve noticed Mariah with her mouth open alot lately, too, like she’s panting. Do we know why she does that?

  5. Margaret says:

    Thank you again for the updates! Can’t wait to see the “babies”.

  6. Dick says:

    Any news on last years birds?

    Thank you for your updates. Fun to read and learn.

    Dick from ND

  7. J.L. Baker says:

    I am addicted to this wonderful site.You do a fantastic job with the updates and information on the saga of these raptors.My question is … how high up is the nesting box? Thank you Jess and keep up the great work!

  8. Mrs. Andino says:

    This is the first year we (myself and my 3/4 grade looping students) have been watching Mariah and Kaver! The excitement in the room is bubbling as we await the eyases arrival with the rest of the falcon watching community. My students and I would love to visit downtown and check out the whole family in flight. I’m not sure when I should schedule the field trip. Will the eyases be able to fly before the middle of June?

  9. Jess says:

    @Jane- We’re still working on a plan for naming the eyases this year. As soon as we get it finalized we’ll let everyone know!

    @James- The falcons have to deal with loud traffic sounds day in and day out, so fireworks don’t bother them at all.

    @Diane- Falcons do indeed pant when they get hot. It’s possible that Mariah was panting, but she may also have just been vocalizing.

    @Dick- In fact, we had recent sightings of two of last year’s fledglings within the past few months. Sabrina was in Rochester through much of the winter, and Rhea Mae was spotted last month in Whitby, Canada in the province of Ontario.

    @JL- The nest box is about 210 feet above ground level.

    @Mrs. Andino- In past years the first fledgling flights have happened around the 20th of the month. Fledging usually happens about six weeks after the eyases hatch.

  10. Gail says:

    Just curious where the “other” falcon goes at night. Hunting? Resting nearby? Never see them together.

  11. Jan says:

    Two questions – Are M & K banded? How soon after the nest box was installed at Kodak did the falcons move in? Thanks for all your insight and updates.

  12. lucy says:

    What happened to M&K ’s other offsprings–still alive and living where?

  13. RICK says:

    Jess – just curious…. when they eat their prey, what do they do with the bones and feathers?

  14. Carol says:

    We were wondering why they don’t build a nest of straw, twigs or something to keep the eggs and themselves warmer?

  15. caye jones says:

    Shall we be getting excited? They should be getting ready to hatch, I am getting exited!

  16. Julie Lowe says:

    We have a pool (no $ involved) over here at Xerox as to the hatching date. Several people have taken guesses ranging anywhere from the afternoon of the 7th to the morning of the 12th, and it’s still circulating around. I’m going to take a guess to answer Carol’s question; it appears to me that all of the rocks surrounding the eggs are meant as camouflage. Perhaps even some of those rocks absorb the sunlight and retain the heat?

  17. Terri says:

    My hatching date guess is May 11th.
    Jess- it was nice to hear updates about Sabrina and Rhea Mae! I did have a few questions I hope you can answer….Do you have any information on any of Mariah and Kaver’s falcons besides Sabrina and Rhea Mae? Any news about Aura? How many other offspring have been banded besides those three and do you plan on banding all the eyasas again this year? When eyases are banded, what type of information is collected and if so, what do you do with it? I know I’ve mentioned before, but I would really love the Mariah/Kaver “family tree” on this website too. Any chance????
    Last, just a comment… I think one of the eyases should be named Jess:)

  18. Melissa says:

    Neither of the parents has been on the eggs for almost an hour. How long are the eggs ok for without a warm body on them?

  19. theresa ingro says:

    It is wired that there is four eggs than five. I wonder what happend to the fifth egg. if you now please give me an e-mail.

  20. [...] from a couple of hours to a couple of days (if you need a refresher on hatching, take a look at this article from 2007). And thanks to our new live video feed, you can watch it as it [...]