Precocial Birds
The contrast between the two extremes is seen most clearly in birds. Precocial species leave the nest shortly after birth or hatching. Megapodes are a family of birds found in Australasia. Their eggs are not incubated by the parents. They are buried in compost, covered with sand and left, though the males test the temperature of the heap and make small adjustments. The eggs, which have a large yolk, hatch with full wing feathers. The hatchlings can run and purse prey, and many species can fly on their first day.