American Toad (Bufo americanus)

Nutrition

     Like all other animals, the American Toad is a heterotroph.  Heterotrophs cannot produce their own food, so they must obtain it from an outside source.  While tadpoles are most herbivorous, mature toads are carnivorous.  Carnivores derive their energy and nutrients from mainly animal tissue.  The toads feed mostly on insects and small invertebrates, as seen below (picture by Karen Francl).  For example, they eat earthworms, sow bugs, spiders, centipedes, millipedes, moths and caterpillars. 

     Unlike other toads, they do not have to expend as much energy foraging.  They can simply extend their extremely sticky and long tongue to quickly capture their prey, whether it’s in the air or on the ground.  Bufo americanus is known for limiting levels of pesky creatures in gardens, like slugs, beetles, and fruit flies.  A study showed that one toad can eat up to 1,000 insects a day.  Although the toad loves to eat, it prefers to eat at night.  This is mainly because the temperatures get too hot during the day, so it will typically aestivate to keep from desiccating.  Aestivation is a period of dormancy; similar to hibernation, but less extreme.  American toads hibernate during the winter, also. They cannot tolerate low temperatures so they burrow by digging backwards into the ground just below the frost line. Hibernation begins when the temperature hits about 50 degrees Fahrenheit, or 9 degrees Celcius. They then wake up just in time for mating season.  To learn more about another creature that hibernates, visit this website about the Ground Squirrel.
     Predators of the toad include raccoons, skunks, garter snakes, water snakes, hawks and herons.  To learn more about the hawk, one of the toads predators, visit this website on the Red-tailed Hawk. Although the toxins would usually affect the organism, these predators have built up an immunity to the toxin.
     Toads in general have a pulmonary and a systemic system.  Their hearts have 3 chambers: 2 ventricles and 1 atrium.  Like other vertebrates, they have a 2 lobed lung that is highly vascularized. The toad uses a unique system to pump air into its lungs.  Negative pressure brings air into the mouth, then the toad closes both the nostrils and mouth to create a positive pressure, which forces air into the lungs.  The toad is more complex than you think!

                                                         To learn more about the American Toad, visit http://warnell.forestry.uga.edu!