Wild Facts About The American Toad

The Life Cycle Of An American Toad

Breeding Season And Calling For Females

• The breeding season for American Toads begins in March and only lasts about two weeks (Tyning 1990).
  • During this time, males gather in shallow water and begin to sing “advertising calls”.
  • An American Toad’s advertising call is a long musical trill that attracts females.
    • When calling, the males’ vocal sacs inflate like balloons to project the sound and can grow larger than their heads.
• Male American Toads sit upright in the water and compete with each other to produce the loudest, most resonant call, while females listen closely, and approach the most attractive males.
• But some male American Toads don’t sing at all.
  • Instead, they stay silent, swim around, and try to grab anything that moves.
  • Sometimes these males grab other males by mistake, which rather defeats the purpose of this particular mating strategy, but they avoid expending energy attracting females themselves.

Eggs And Tadpoles

• Like all amphibians, American Toads require freshwater in which to lay their eggs.
• Female American Toads are prodigiously fertile.
  • A single female may lay up to 6,000 eggs.
  • The eggs stretch out in long, gelatinous strings, which the females attach to underwater plants (Martof et al. 1980).
  • Tadpoles hatch from the eggs within a few days.
  • At the height of the breeding season, a single, small, shallow pool may teem with hundreds of tadpoles.

• American Toads must lay a great number of eggs during every breeding season because very few tadpoles survive to adulthood.
  • Tadpoles start out life tiny and aquatic, with tails, gills, and no legs.
  • Trapped as they are by the volume of water in which they hatch, they fall prey to numerous predators.
    • Like the adults, American Toad tadpoles also manufacture bufotoxin as defense against predators.
  • Only a small percentage of tadpoles survive long enough to metamorphose into bulky, tailless, poisonous land-dwelling adult toads.

Is It Edible? Good, We’re Done

• Besides the risk of being eaten themselves, American Toad tadpoles face fierce competition for food amongst themselves.
  • While they don’t actively kill each other, American Toad tadpoles do eat dead siblings—a behavior known as passive cannibalism (Heinen and Abdella 2005, https://doi.org/10.1674/0003-0031(2005)153[0338:OTAOPC]2.0.CO;2).