What do you know about bald eagle eggs?

Question #1: How long does it take a bald eagle egg to hatch after laying?

Bald eagle eggs
Sorry! It takes 35 to 39 days for a bald eagle egg to hatch after Mom lays it!

Question #2: What is the optimal temperature for egg incubation?

Second Decorah North Nest Egg!
The optimal temperature for bald eagle egg incubation is about 99 degrees. Since Mom and Dad have body temperatures of about 105 degrees, they have heat to spare!

Question #3: On average, bald eagle eggs are:

Bald eagle eggs
Sorry! Bald eagle eggs are about 2.9 inches long and 2.2 inches wide. Learn more about eggs here: http://raptorresource.blogspot.com/2015/03/egg-colors-and-shapes_24.html

Question #4: Where does the calcium for a bald eagle’s egg come from?

The calcium for Mom's eggshell comes from her diet and her skeleton. Her medullary bone acts as a reservoir for the supply of eggshell calcium if enough isn't available in her bloodstream during calcium deposition! While Mom eats bone, many birds eat snail shells to help supply them with the calcium they need to build their own bones and lay healthy eggs.

Question #5: How long does it take a female bald eagle to build and lay an egg?

Cross section of an avian egg
Once Mom has deposited a fertilized yolk in her oviduct, it takes about 48 hours for her to build and lay an egg! The egg is fertilized at the infundibulum, gets most of its albumen in the magnum, gets its inner and outer membranes in the isthmus, and is covered with calcium in the uterus or egg shell gland.

Question #6: What is the window of time for egg yolk fertilization to occur?

Fertilization of the Eagle Egg
Dad's sperm have just 15 minutes to fertilize Mom's yolk before it seals over and fertilization is no longer possible! Sperm and yolk meet at the top of the oviduct in the infundibulum, a special organ where fertilization occurs.  

Question #7: When does an embryonic eagle’s heart begin beating?

Ten stages of embryonic development
Sorry: a bald eagle's heart begins to beat inside the shell roughly 72 hours after an egg is fertilized. Think of that the next time you see a recently laid egg!

Question #8: How does an embryonic bald eagle get oxygen in the egg?

A chicken embryo in the egg
The embryo is attached to the chorioallantoic membrane or allantois - a special membrane that exchanges gases through the porous eggshell. This membrane acts as a respiratory organ, gets minerals from the shell, and handles waste!

Question #9: True or false: an egg will die if it isn’t constantly incubated!

Eggs can die of cold, but they can also die of heat. Mom and Dad will get off the eggs to give them a chance to cool down, to let them air out, and to reduce humidity.

Question #10: What part of the egg becomes the eaglet?

D25, D24, and Mom
None of the above! The union of sperm and egg forms a blastodisc, or germinal disc. As cells dive and reproduce, they build the eaglet's body. The egg white, egg yolk, and various membranes all exist to support the embryonic eaglet.

Question #11: What color is a bald eagle’s egg?

An image of eggs
A bald eagle lays white eggs!