Incubation begins ….

IMG_2511 ldIncubation is the boring segment of the bluebird life cycle.  It’s about like watching grass grow.  Nothing in the nestbox changes for a couple of weeks.  It’s been cool this week with temperatures below freezing.

Mama enjoys a mealworm breakfast after a frosty night in the box. Click to enlarge.

Mama II began sitting on her eggs 25 March.  Bluebird eggs hatch in 12-14 days.  I normally use 13 days in my estimates.  But, since it’s cool, I’m going with 14 this time.  That means the bluebird eggs should hatch ~09 April.

Although nothing visible will be going on with the eggs, the danger from HOSP remains.  I still have a handful I can’t trap and Daddy II is not as protective of his turf as my old Daddy.  Worries me some.

Have you ever wondered why bluebirds and other birds like jays are blue?  Ornithologists stellar'sjayhave known for decades that red and yellow colored birds get their pigmentation from their diet.  In the past few years Yale ornothologist Richard Prum has discovered why bluebirds are blue.

A Stellar’s Jay I photo’d in Santa Fe.

Prum discovered that as a blue feather grows, something amazing happens. Inside each cell, stringy keratin molecules separate from water, like oil from vinegar. When the cell dies, the water dries away and is replaced by air, leaving a structure of keratin protein interspersed with air pockets, like a sponge or a box of spaghetti. When white light strikes a blue feather, the keratin pattern causes red and yellow wavelengths to cancel each other out, while blue wavelengths of light reinforce and amplify one another and reflect back to the beholder’s eye. The result: blue, an example of what scientists call a structural color (as opposed to a pigmented color) because it’s generated by light interacting with a feather’s 3-D arrangement. And different shapes and sizes of these air pockets and keratin make different shades of blue.

If you haven’t signed up to follow the Bluebird Diary, I encourage you to do so.  That way you’ll know for sure when the eggs hatch.  If you get bored, I have lots of bluebird photos at

First Brood Summary

  • First sign of nest building                09 March
  • Nest completed                                   15 March
  • First egg laid                                       18 March
  • Second egg laid                                  19 March
  • Third egg laid                                     20 March
  • Fourth egg laid                                   21 March
  • Fifth egg laid                                       22 March
  • Incubation begins                              25 March

About lindell dillon

Lindell Dillon is retired and lives in Norman, OK. He grew up in Duncan, attended Cameron College and graduated from the University of Oklahoma. His interests include photography, nature, birding, and investing. Oklahoma Master Naturalist, alumnus Norman Police Department Citizens Academy.
This entry was posted in Bluebirds and tagged , , , , , , . Bookmark the permalink.

4 Responses to Incubation begins ….

  1. Juliana Michael says:

    Very cool!

    Juliana Baum-Michael Metro Brokers of Oklahoma mobile:405-409-3610 fax: 405-701-1716

  2. pamcolander says:

    Our current BB pair are still investigating all the boxes in the yard. Congrats on your clutch and fingers crossed that it leads to a successful fledge!

  3. Velva says:

    Very cool! I am looking forward to the eggs hatching. How long do the bluebirds nest in the box?

    I have a second bluebird box up….I checked the box and a nest of pine straw is evident. I did not see any birds. Fingers crossed.

    The first house definitely has chickadees. I checked the box and mama flew out.

    Looking forward to your next post.


  4. Very interesting info about the blue coloration. I always enjoy your posts and the pictures you include. I don’t think I’ve ever seen a Stellar Jay.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s