How Big Does a Megapode Get?
Imagine, a bird that does not sit on its eggs! How then do they stay warm to hatch? Meet the megapode or incubator bird of Australia. The name means ‘big feet’ and they do have that! And these feet serve a very good purpose. The bird weighs 3-4 pounds fully grown. The male uses his big feet to build a nest for his mate.
How Large Is a Megapode’s Nest?
And what a nest it is! It measures as large as 50 feet wide and 20 feet high, made of decaying vegetation. Once the male has built the nest, the female tests the nest to see if it will be adequate for her eggs. While she does this, the male starts to build another nest, just in case she doesn’t like the first one.
When she accepts the nest, the female megapode starts to lay eggs deep in the vegetation, one egg every three days for up to seven months. That’s 20 to 35 eggs total. Since the egg is the size of an ostrich egg, that is quite a workout for mom! The eggs take approximately seven weeks to incubate, meaning that up to 16 eggs at one time are in this huge nest. When she finishes laying the eggs, she leaves, never to return to the nest.
How Are The Megapode’s Eggs Warmed?
But neither poppa nor momma will ever sit on the eggs. They are warmed by the heat of the decaying vegetation. (In some species, the eggs are warmed by solar energy and others volcanic heat.) Once an egg is laid, the male begins his full-time work- maintaining proper heat for it.
Each egg must be exactly 91º to develop properly, plus or minus one degree! The male will dig down and check the temperature of each egg. Scientists are not sure how he knows it is 91º, whether he measures it with is tongue or his beak. But if the egg is too warm, he will pile sand on the nest. On cool days he uses his big feet to push sand off or gets more vegetation. Each centimeter of decaying material raises the temperature 3ºF. Scientists had to figure this out. The megapode already knows it. He must also be sure the eggs are at a constant 99.5% relative humidity.
The chicks inside the eggs also need sufficient oxygen. Each egg shell has hundreds of tiny cone-shaped pores in it, the pointed end being toward the chick. As the chick grows, it needs more oxygen and wears away the inside of the shell. This makes the pores larger and gives the chick more oxygen. Ingenious, right?
What Do The Chicks Do When They Hatch?
Once the chicks hatch, they take two or three days to work their way through the nest covering to the surface. They are hatched with all their feathers and immediately are on their own. This means no parent is around to teach the babies what 91º or 99.5% humidity means. But they will do it right just the same.
Can Evolution Work with The Megapode?
Everything about this unusual bird declares its Creator. If you doubt that, consider where the megapode would be today while the male evolved the senses to detect the heat so precisely and the knowledge that 91º is perfect. Just one generation of waiting would mean extinction.