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Anaxyrus fowleriFowler's Toad

By Marion Vereecke

Geographic Range

Anaxyrus fowleri is a toad commonly found in areas of the Atlantic Coastal Plain. Its range consists of New Hampshire to eastern Texas, eastern Arkansas, Missouri, and southeastern Iowa, eastward into Michigan through Ohio, and West Virginia to the Atlantic coast. Extensions include up the Hudson, Delaware, Susquehanna, Ohio, and other rivers and into southern Ontario, along Lake Erie. (Wright and Wright, 1949)

Habitat

Anaxyrus fowleri prefers to live in open woodlands, sand prairies, meadows, and beaches. They like to burrow into the ground during hot, dry periods and in the wintertime.(Harding 1992 and Harding 1997)

Physical Description

Anaxyrus fowleri comes from the order Anura which are animals noted for having a toothless jaw and enlarged parotoid glands behind the eyes. They are usually brown, gray, or olive green in color and have black edged dark spots on its back, with a light middorsal stripe. In each of the dark spots there are found to be three or more warts. The belly is usually whitish and almost completely unspotted. Males are often found to be darker in color while females are found to be lighter. Anaxyrus fowleri is noted for having a single dark spot on its otherwise spotless belly. Its body measures between 5 to 9.5 centimeters in length. Anaxyrus fowleri tadpoles have a short oval body and a long tail with an upper and lower fin. Their size is 1 to 1.4 centimeters long.(Wright, 1949 and Collins, 1991)

Development

Reproduction

Anaxyrus fowleri is known to reproduce in warmer seasons of the year, usually between the months of May and June. Breeding sites are located in shallow waters that are very open, including farm ponds, lake edges, marshes, and woodland ponds. Breeding habits of Anaxyrus fowleri are very similar to Bufo americanus. The male will migrate to the breeding sites where he will begin calling his mate in intervals that can last up to thirty seconds. The call often attracts both male and females which will cause mistaken identities in the breeding process. This mistake occurs when one male tries to mate with another male. Fortunately, the first male will realize the mistake right away because the other male will let out a chirping release call that informs the first one of his mistake. When the male finally meets his mate, the male will try to clasp the female from behind. From this position the male can fertilize up to 7,000-10,000 eggs. Fertilization is external. The eggs are known to hatch in two to seven days. The tadpoles will begin to undergo the change into tiny toads thirty to forty days later. In one growing season, Anaxyrus fowleri may grow to sexual maturity, but slower growing individuals may take up to three years before they reach their sexual peak.(Harding, 1992 and Harding, 1997)

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)

Behavior

There are some conflicting opinions about the behavior of Anaxyrus fowleri. One source indicates that this type of toad is completely nocturnal (Behler,1996). Another source states that Anaxyrus fowleri is mostly active in the daytime, except during hot days or very cold days when it will burrow into the ground (Harding, 1992). Both sources agree on how Anaxyrus fowleri reacts to predators and the defenses they use to protect themselves. Potential predators of Anaxyrus fowleri include snakes, birds, and smaller mammals. One defensive behavior it will use is its coloration to blend into its surroundings. These toads are able to do this because they tend to have coloration that is more nature-like, or earth tone. Another defense includes a noxious secretion that comes from the large warts on their backs. If attacked, this secretion will irritate the predator's mouth and, if ingested, can be poisonous to smaller mammals. If roughly handled, Anaxyrus fowleri will also lie still on their backs and pretend to play dead.(Behler, 1996, Harding, 1992, and Harding, 1997)

Food Habits

The adults eat insects and other small terrestrial invertebrates, but shy away from earthworms, unlike their close relative, Bufo americanus. As a tadpole, Anaxyrus fowleri use their mouth, which is rimmed with tooth-like structures, to scrape attached algae from rocks and plants. The tadpoles are also known to feed on bacteria and other organic material from the water.(Harding, 1997)

Economic Importance for Humans: Positive

Anaxyrus fowleri is useful to have in gardens because it eats many insects and other small invertebrates.

Conservation Status

Protection of the breeding sites for Anaxyrus fowleri is very important to their existence. Off-road vehicles that are commonly used in beach and dune habitats are damaging to this species. Also, the use of agricultural chemicals share in the blame for the decline of Anaxyrus fowleri in some areas. They are considered a species at risk in Ontario. (Harding, 1997)

Other Comments

There are no other pertinent comments.

Contributors

Marion Vereecke (author), Milford High School, George Campbell (editor), Milford High School.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

References

Behler, J., N. Society. 1996. National Audubon Society Field Guide to North American Reptiles & Amphibians. United States: Alfred A. Knopf, Inc..

Collins, J., R. Conant. 1991. Peterson Field Guides: Reptiles and Amphibians ( Eastern/Central North America). Boston and New York: Houghton Mifflin Company.

Harding, J. 1997. Amphibians and Reptiles of the Great Lakes Region. Ann Arbor: The University of Michigan Press.

Harding, J., J. Holman. 1992. Michigan Frogs, Toads, and Salamanders: A Field Guide and Pocket Reference. East Lansing, MI: Cooperative Extension Service, Michigan State University.

Wright, A., A. Wright. 1949. Handbook of Frogs and Toads of the United States and Canada. Ithaca, New York: Comstock Publishing Company, Inc..

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