American Toad

As you are out walking at this time of year, whether in neighborhoods or natural areas, you may hear a musical trilling in the background.  This is the call of Bufo americanus, the American Toad, as it returns to the banks of local streams and ponds.  Male toads emit a high pitched trill that may last 30 seconds or more, as they actively seeking mates for breeding.  They call constantly during the daytime and early evening, and are often heard as part of the background sounds of the neighborhood.

American Toad, Tanya Dewey, Animal Diversity Web

The American Toad has a compact body with dry, warty yellowish-brown backs and sides.  They have short hind legs that allow them to walk or hop, but not take long leaps as do frogs. Adults are typically 2″ to 4″ with the females slightly larger than the males, but larger sizes up to 7″ have been observed in some localized areas.  These toads are found from the Mississippi River to the East Coast and from middle Canada to southern Georgia.

As in all frog and toad species, only the males call, hoping to attract a female by song alone.  American Toads like shallow, quiet waters with scant to moderate amounts of fully to partially submerged vegetation.  The male will select a stationary position in a desirable habitat, call, and after a female joins him, they will mate.  The female then lays her eggs in the water.  Breeding is often initiated by rainy days and warm evening temperatures.  A female will deposit between 2,000 and 20,000 eggs contained in two gelatinous strings of mucus several inches under the water’s surface and they may be attached to nearby vegetation. 

American Toad eggs by Judy Gallagher

Eggs hatch in 2 to 14 days depending on water conditions.  Tadpoles are black in color, and they will change into tiny toadlets in six to ten weeks.  Large groups of toadlets can be observed leaving the ponds for the open woodlands, prairies, marshes and your backyard.  The American Toad reaches sexual maturity in two to three years and may live ten years, although mortality from predators and human impact is high.

At this time of year, you may observe toads in your own backyard.  If you try to sneak up on a toad, especially in the evening, it will immediately stop calling if it hears you.  However, if you wait quietly at the edge of a pond for four to five minutes, the toads in the area will resume their singing.  Species are distinguishable by their song, and you can hear the different songs including the American Toad at the Illinois Natural History website: INHS Frog & Toad Calls.

If you should find a toad, see if you can observe some of the unique characteristics of these animals.  Do you see its ears?  They do not stick out from the head, as ours do.  Toads have a round patch positioned right behind their eye that is a tympanic membrane, able to detect and identify various sounds.  Can you observe it catching any prey?  Their tongues, which are long and sticky, are attached at the front of their mouths, not the back as ours are.  As insects fly by, a toad can flick its tongue out at an amazing speed to snare a meal.  You can watch this behaviors at Discovery News.