DIFFERENT LOOKING BLUEBIRD EGG CLUTCHES – MARCH 2012

It’s fun to see how the egg clutches look on my nestbox visits.  Also, I watch to see how the female turns the eggs with her feet and how they change configuration for even incubation during those 14 days or so.   Some eggs have white marks in them; others with spots of dried blood.   When the eggs pass through the female’s oviduct, that’s when they are colored blue on the outer eggshell, through the pigmentation cells she has to allow this.   Occasionally, white eggs will be laid in bluebird clutches.   This means the pigmentation gene is missing during the egg-laying process.  Here are some recent photos I’ve taken within the past two weeks of the clutches I’ve seen this year.  You’ll see one photo (bottom right) required a mirror so I could see the set of eggs.  This can be challenging to do it quickly and get the picture before the adults get too nervous that I’m at their nest.  I try to make my nest visits as fast as possible and still get some good details!  This nest was built quite high and she placed more grasses inside the pine needle nest.  This is one of the reasons I enjoy other species using the boxes, not just bluebirds.  It’s really entertaining, as well as educational, to see how the species differ in their nesting habits.   I will be seeing the Carolina Chickadee and I’m hoping to see some Tree Swallows on my trail this year.   They are marvelous birds.  I wish I could spy on many different species nesting.  The live cams on eagles, red-tailed hawks, and others are fascinating.  The Cornell Lab of Ornithology has several cams going presently.  The hummingbird live cams are truly my favorite of all.