Let's learn about eggs
"Birds generally lay eggs that are 1 to 10 percent of their body weight. But the kiwi produces a single egg that is 20-25 percent of its weight. The San Diego Zoo's Web site compares it to a 120-pound human female giving birth to a 24-pound baby."
This and more at 10 Things You Didn't Know About Eggs
This and more at 10 Things You Didn't Know About Eggs