Woo hoo for the first egg to hatch this morning at the Franklin Institute nest - exactly 32 days from when Mom laid the last egg on March 31. This is the exact same time - 32 days - she has taken every year.
Observant cam watchers first noticed a possible pip in one of the eggs at 7:56 AM, and then this was confirmed at 8:14 AM.
A
pip or tiny hole in the egg is the first indication that hatching is
underway. John Blakeman gave us some great information on pipping and
hatching back in 2010, so let's do a review! I added a couple of images
by way of explanation, but these are not of hawk eggs or eyasses.
From John Blakeman:
"We
all expect just a wonderful experience as we witness the hatching,
with the first indication being that pipping has begun. Pipping is
when the little eyass inside the egg begins to thrust its beak out at
the end of the egg and will create a small crack. That’s pipping, the
cracking of the egg, and it’s very important.
It’s done by the "egg tooth," a slight temporary projection on the top of the beak.
With a rounded
bill, it would be otherwise very hard for the little eyass to poke any
sort of hole through the egg shell. But the slightly pointed egg
tooth will allow the weak eyass to accomplish this.
T
hat
will be the first sign of hatching. Someone will see the slightest
crack on the end of an egg. Everyone will get understandably excited.
But
then disappointment will set in. We would all expect the little eyass
to continue to break open the entire egg after the first pipping and
step right out into the world. But it doesn’t (and shouldn’t) happen
that way.
After
pipping, the little eyass stops pecking at the egg shell and remains
rather quiet. (Wish we had a microphone buried in the nest so we could
hear all of this.) The eyass is quiet for two reasons. First, she has
used a lot of energy punching her beak out at the egg, so she tires
of all this activity. But more importantly, her lungs are not ready to
be exposed quickly to open, dry air.
For most of a
month, her lungs have been filled with fluids, and she’s been
breathing very moderately through simple air diffusion into her body
tissues. But in the last week or so, things start drying out inside
the egg and slowly her lungs will get filled with the gases in the end
of the shell. It’s still 100% humidity in there, and all is well.
But
after pipping, dry air from the outside begins to replace the moist
air inside the egg. If that happens too fast because the pipping creates
an overly opening, the lungs dry out too rapidly and the eyass simply
dies from non-functioning lungs.
So,
we must be patient when we see the first pipping. It could be a day
or longer before the eyass finally emerges. There is no need for the
little hawk to get out of the egg. She’s happy with the humid air in
there, while her lungs start to adjust to cold, dry air on the outside.
At
the end, when she’s ready, the eyass will make some final thrusts
with her head and create an opening big enough from which to emerge.
She will hardly be able to hold up her head, and she may not eat or be
fed for up to a day. It can be so frustrating to see the little hawk
lying down in the nest, without the energy to even stand up and open
its mouth for the tiny tidbits of food the formel will offer when the
eyass first takes this "I’m hungry" posture.
We
just have to wait for all of this to happen. To rush any of this
would be to endanger the health of the eyass. In captive breeding of
raptors, falconers know that they must never help the little eyass get
out of the egg too soon. The eyass instinctively knows what to do, and
when to do it. We must merely stand back and watch this marvelous
sequence of behaviors.
And
we need to continue to thank The Franklin Institute for allowing us
to watch all of this. We raptor biologists can never see any of this
when aiming our spotting scopes at wild nests. It’s all way up there
in a tree, and we can see only the haggards coming and going. Here at
the Franklin Institute, everyone gets to look right down inside the
nest and see it all. And once again, we should get to see some pipping
and then hatching, followed by the formel feeding the newly-emerged
downy eyasses.
But
I offer a sobering thought, one that we must consider and be gravely
ready to confront. As good as these haggards have been, there can be
no guarantee that all three eggs will pip, hatch, or have their
eyasses grow up and fledge. The stark reality is that one or more
eyasses may fail to hatch, or fail to thrive and die.
Eyass
deaths are rather common. It’s just part of nature. Should an egg
fail to hatch, or a little eyass dies, we must accept this as a
natural part of the entire process.
Now,
let’s sit back and wait, with our eyes glued to the screen. Let new
red-tail eyasses grace the skies of Philadelphia once again!"
–John Blakeman
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