Expert: Julia Booth - 7/14/2008

Question
Are birds such as hummingbirds considered "pregnant" just prior to laying eggs? Or is there another term for it?

Answer
That's a good one -do birds get pregnant. Technically, yes. But the term we use is "gravid" -which basically means full and ready to lay the egg. Hummingbirds typically only have two eggs in their clutch, simply because they are so tiny. Larger birds have larger clutches. One eggs is laid a day and then incubation begins when all the eggs are laid -this is so that they will all hatch at the same time.

Birds that are preparing to incubate usually develop a bald spot on their belly -this is so their skin and body heat can come into direct contact with the eggs.

The term "nesting" is actually applied to humans as well -in that there are some behaviors typical of human females just prior to giving birth, such as cleaning everything in sight and rearranging their surroundings until they are satisfactory.

Birds are not that different from mammals. Their sex organs are stimulated by androgens (hormones) released from the hypothalamus, just like humans. Except for them, the actual process of intercourse only lasts a few seconds.

Here is an extremely graphic, but excellent explanation of the avian reproductive process: http://people.eku.edu/ritchisong/avianreproduction.html

Enjoy!

Julia