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Frog Vibrations

June 11, 2008

Some tadpoles improve their odds of survival by deciding when to hatch.

Transcript

BOB HIRSHON (host):
Life-saving vibrations….I’m Bob Hirshon and this is Science Update.

Red-eyed tree frogs lay their eggs in the vegetation that hangs from trees above ponds in Central America. When the tadpoles hatch, they drop into the water below. But snakes are a major predator of tadpoles before they hatch. According to biologist Karen Warkentin of Boston University, the tadpoles avoid this fate by hatching prematurely if a snake bites at their nest.

KAREN WARKENTIN (Boston University):
The embryos start squirming around inside their egg capsule and break out and within seconds, they can drop into the pond below.

HIRSHON:
But she says hatching early makes the tadpoles extra vulnerable to predators in the pond itself. However, she and her colleagues recently discovered that the tadpoles can distinguish the vibrations caused by snake attacks from all other nest disturbances. This ensures that they’ll only hatch early when threatened by a snake. I’m Bob Hirshon for AAAS, the science society.