Monday, April 27, 2009

Hatch expected this week

Many, many eyes are on the Columbus falcons anxiously awaiting hatch. Incubation takes around 33 days, however it is difficult to predict when the birds actually begin setting full time. Counting from the date of the 4th egg (March 27), 33 days is Wednesday, April 29th, so that is when we predict hatching to occur. However, it isn't an exact science thus that prediction may be off by a few days. Don't be surprised if hatch begins earlier and don't panic if hatch is late! And, remember that the eggs won't all hatch at once - they usually hatch over a couple of days time.

Given that, here are some signs to help tell when hatch is close. A day or so prior to hatching the chicks will begin vocalizing from inside the egg and pecking to work their way out. The adult birds can hear the chirping and feel the vibration and so their behavior will change. While throughout the majority of incubation they have set tight on the eggs (except for during the extreme warm temperatures over the weekend when the adults were moving the eggs and shading them to help keep them from overheating) the incubating adult will become very restless. It will get up and look down at the eggs more often, settle back down, and be up looking again within a short time. Unfortunately, at this time there is no sound with the nestbox video.

Eggs can hatch at any time of the day or night but we usually see the most hatching during daylight hours. The process will start with a pip--a small hole pecked through the shell from the inside by the chick using it's "egg tooth." It will take some time from pipping for the chick to actually come completely out of the shell. Don't be surprised if you see Scout eating the egg shells. This is one way for her to replenish calcium in her body that was lost from her system when she produced the eggs initially.

After hatching the chicks will need to be kept warm so Scout will brood the hatchlings. This may look similar to incubation but she will actually be sitting up higher and may hold her wings out from her body more than we see during incubation.

I'll be in the field a considerable amount of time this week and so may not be able to post updates as soon as they happen. However, I will update the blog as soon as I am able with photo highlights when possible.