Birds
Kiwi
Apteryx mantelli
About
New Zealand's iconic flightless bird is about the size of a chicken but lays an egg that's up to 6 times larger than a chicken egg relative to body size. The kiwi has the largest egg-to-body-weight ratio of any bird.
Their Eggs
Enormous relative to body size — the egg is about 20% of the female's body weight. Smooth, white to greenish-white shell.
Egg Size Comparison
Fun Fact
The kiwi egg is so large relative to the bird's body that the female must fast for 2-3 days before laying because the egg compresses her internal organs, leaving no room for food.