Keeping an eye on the nest

March 11th, 2010 By Kathy Van Mullekom in Biology / Plants & Animals

You can catch the hatch of the first egg in the tree-top bald eagle nest at Norfolk Botanical Garden in southeastern Virginia via the garden's special Web cam -- norfolkbotanicalgarden.org.

But, you may want to first get a snack and beverage to tide you over because watching the cam can keep you glued to your seat for a spell, according to experienced bird watchers.

The first egg, laid Jan. 31 into a snow-filled nest, is scheduled to crack open sometime this week, having gone through a 35-39 day . Two more were laid Feb. 3 and 6.

This is the seventh year for this pair of parenting eagles to nest at the botanical garden. They've successfully raised 12 eaglets.

So how does the chick -- also called an eagle or hatchling -- get out of that white oval-shaped eggshell?

Reese Lukei with the Center for at the College of William and Mary in Williamsburg, Va., answers these kinds of questions in his eagle nest blog at http://eaglenest.blogs.wm.edu/2010/01/06/adult-bald-eagles-at-norfolk-botanical-garden/

"By now the developing embryo is almost fully formed and has developed a strong muscle on the back of its neck called a 'hatching muscle', and a small sharp 'egg tooth' on its upper beak," Lukei writes.

"Hatching is a very physical process and a challenge that can take two to four days. Up to this time the soon to be hatchling has been all folded up, but now begins to stretch out, and punctures the inner membrane with its beak at the blunt end of the egg and for the first time breathes 'air.'

"The chick then slowly rotates counterclockwise by pivoting its legs and with the 'egg tooth' scratches the inside of the shell. With the 'hatching muscle' it punches a hole (called pipping) in the eggshell. With body movements and stretching the eaglet breaks the eggshell into two pieces and the hatching process is finally complete."

Virginia wildlife biologist keeps a similar blog at www.dgif.virginia.gov/eaglecam/

Once all three eggs hatch, the parents constantly bring food to the and keep a close eye on their offspring. Late spring or early summer, the most amazing sight is watching the eaglets learn to fly and hunt for themselves, according to wildlife experts.
___

MORE BIRD WEB CAMS

• http://watch.birds.cornell.edu/nestcams/home/index
• http://www.ustream.tv/channel/hummingbird-nest-cam

(c) 2010, Daily Press (Newport News, Va.).
Distributed by McClatchy-Tribune Information Services.

"Keeping an eye on the nest." March 11th, 2010. http://phys.org/news187515461.html