 Steve Roble photo, MA NHESP This page illustrates the typical life history of a Wood Frog. The entire process begins when a male frog gives off its mating call (usually in spring). The call attracts the female to come over to the male. | |
| The male and female frogs then enter amplexus, where the eggs leave the female and are externally fertilized. These eggs are encased in a gelatinous fluid and laid in water. During these breeding periods, a female may deposit anywhere from 19 to 30,000 eggs! Each egg sack alone can, depending on the species, contain hundreds and hundreds of eggs. Since frog eggs are a favorite delicacy of many predators, laying the eggs in large numbers usually assures that at least a few will hatch into tadpoles, and an even fewer number will grow to be adults. | |
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| When the tadpole has had enough time to develop inside the egg, the envelope holding the egg in the mass will either disintegrate or a chemical that the tadpoles secrete will cause the egg to break up. The tadpole will then emerge, using its external gills to collect oxygen from the water and its small, specialized mouth to collect algae. The tadpole will quickly develop a long, compressed tail which helps it to maneuver around in the water. | |
| The tadpole's anatomy then gradually starts changing in anticipation of its new life on the surface. Hind legs will start to appear, its digestive tract changes to prepare for its forthcoming insect diet, it developes forelegs, and the froglet then hops onto land. This transformation process can last anywhere from 12 days to 3 years, again depending on the particular species. | |
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| At last the frog is fully developed. The tail is now completely off and the frog has changed enough to let it live on the surface. After 1 to 4 years, this new frog will be old enough to start breeding, and the cycle of life continues ever onward... |  |
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