Wednesday, June 13, 2012

Getting Bigger . . . and Getting Fierce

This week's kestrel nest box inspection found both nests still with five eyases, and starting to get their feathers.  The box overlooking the field by the house is developmentally just a few days behind the one in the back field.  The feather development is not enough yet to be able to sex the nestlings, at least not by me.  Perhaps by next week I can say definitively.  I think there will only be about one more nest inspection before the babies are big enough that there could be a risk of them bailing from the box before they should.  So, I'll plan for just one more check next week.  After that, I hope to set up my spotting scope at a safe distance and use my camera for pictures as they come out of the box.  It's not the best equipment, so the pictures won't be as good as some of those taken by the experts out there (Rob Palmer) . . . but they will be my pictures.
This week I did pull one eyas from each box and took a picture.  Though fierce looking, that is actually a fear response.  You can clearly see the tiny notches in the beak that are unique to falcons.  The tomial tooth aids in the killing of prey birds, so often on the menu of falcons . . . even the smallest ones.  Also check out the sharp little barbs at the end of the tongue.  These help to make sure food only goes in one direction . . . down the gullet.
Reaching into the box, and returning the baby that I had pulled, several of these baby kestrels manifested the protection behavior common in raptors.  They flip themselves over to defend with their feet.  I did get grabbed by the one on the left, but it is about as offensive as being grabbed by a kitten.
All the eyases in the back box were also piled together.  It is a somewhat cooler day today.
Look!  The Ultimate Angry Bird!
All the nestlings were chubby and well fed.  The two sets of parent kestrels are finding plenty to keep their babies healthy and growing.
Here you can see the first feathers emerging on the back of the baby I had pulled.  I could be wrong at this early stage, but I think this will be a female.  Kestrels are unique among our North American Raptors in that they have different color patterns for each sex, or plumage polymorphism.  By next week I should be able to say how many females and how many males are in each of the nest boxes.
After returning the baby to the box, they too were being a bit defensive of their space.

On the drive home from the back fields, we saw both of the red tail hawk parents sitting on one of the poles on the farm.  They moved their nest, and we have yet to look and find it.  However, I suspect we know the area where it may be located.  One parent flew constantly over our heads screaming at us where we stopped to look.  Perhaps soon Richard and I will take a more thorough walk and find the new nest tree.  The red tails should soon be branching and fledging as well.  Better hurry!

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