Fowler's Toad Bufo fowleri

Adult from Boone County

Identification

Adults of this species are medium-sized with warty tan or grayish skin. Though they are capable of changing colors (as are other frogs), Fowler's Toads are generally lighter colored than American Toads. Ventral coloration is light and the venter is either unmarked or with a single dark spot under the throat. Fowler's Toads have large, irregular, dark blotches dorsally, often enclosing more than three warts. The cranial crests are indistinct and the tibial warts are not enlarged. Juveniles are similar to the adults. An adult Fowler's Toad can be 2-3 in (40-70 mm) in length.

Adult from Brown County
Juvenile from Parke County
Metamorph from Montgomery County

This species deposits their eggs in shallow water, in long ribbon-like strands of up to 10,000 eggs per female. Tadpoles are small, dark and essentially indistinguishable from American Toads until near metamorphosis.

American Toads (Bufo americanus) are often found alongside Fowler's Toads and the two can be difficult to distinguish from one another. The matter is further complicated by occasional hybridization between the two species. American Toads rarely have dorsal blotches that enclose more than one or two large warts, whereas Fowler's Toads often have blotches that enclose multiple smaller warts. While American Toads may have heavy dark mottling ventrally, Fowler's Toads usually have either one large spot or no dark coloration at all. American Toads have enlarged tibial warts that Fowler's Toads lack. The cranial crest of American Toads is pronounced and either disconnected to the parotid gland or only connected via a spur while the Fowler's Toad has a much less prominent cranial crest that sits directly on top of the parotid gland. While coloration is by no means an absolute way to identify this species, American Toads are more often reddish or brown in coloration while Fowler's Toads tend to be grayish or olive-gray in coloration. While the two are sympatric (inhabit the same areas) throughout most of the state, there is some differentiation in habitat use with Fowler's Toads being the more common species in sandy and dry environments.

Call

Their call is a trill similar to that of American Toads. Fowler's Toads have a lower-pitched, nasal-sounding call that is harsher than that of their close relative. Listen to the call courtesy of the Indiana DNR.

Ecology and Conservation

Fowler's Toads are generalists that are most often associated with open, sandy areas. They will also inhabit rocky hills, upland forests, floodplains, suburban landscapes, and agricultural areas. There is substantial habitat overlap with American Toads, though Fowler's Toads are generally more abundant in sandy and dry areas. During the summer, these toads are primarily nocturnal and are most active on warm, humid nights. Adults have distinct home ranges and can apparently hold the same foraging territory for multiple years. These toads are active from late spring to fall, emerging during mid to late April and disappearing some time from late September through October. These toads feed on a variety of invertebrates and often sit in wait for prey on warm nights.

Fowler's Toads are summer breeders that rely on shallow, ephemeral waters. They seem to be prone to breeding in temporarily flooded pools, ditches, and fields but will readily breed in the shallows of larger bodies of water such as rivers and reservoirs. Fowler's Toads begin calling in late April or early May and continue through early July. Breeding activity may be prompted anytime during the spring and early summer when heavy rain fills temporary pools and ditches. Eggs hatch within a few days and the larval period is relatively short with metamorphic frogs appearing only one to two weeks after breeding occurred.

Rocky creek from Jefferson County
Sandy roadway from Newton County

Fowler's Toads are widespread and adapt well to most habitats including heavily disturbed areas. In general, there are no immediate threats to the persistence of this species in Indiana. This being said, many natives to Indiana will comment on a perceived decline in toad populations during the mid-late 1900's. It is likely that this corresponds with a general decline in amphibian populations but toads are more often seen around buildings and their decline is therefore more visible.

Distribution

Fowler's Toads are found throughout much of eastern North America from east Texas into Missouri and Illinois, east to northern Florida in the south and New Hampshire in the north. They are common throughout the state of Indiana, though they are most prevalent in the southern half of the state and in the northwestern sand prairies.

Taxonomy

There are no currently recognized subspecies of the Fowler's Toad (Bufo fowleri). Frost et al. (2006) recommended placing these toads in the genus Anaxyrus, but Pauly et al. (2009) argue against this, instead suggesting that Anaxyrus be recognized as subgenera of the intact Bufo. The Fowler's Toad belongs to the family Bufonidae, which is diverse worldwide and is represented in Indiana by a total of two species.

Is it dangerous?

It is a common myth that toads cause warts when handled, but this is in no way true. Toads do however, have mildly toxic secretions that are used as a defensive mechanism against predators. These are not dangerous to humans unless ingested, but it is wise to wash your hands thoroughly after handling this species.

Literature Cited

Brodman, R. 2003. Amphibians and Reptiles from Twenty-three Counties of Indiana. Proceedings of the Indiana Academy of Science 112:43-54.

Clark, R. D. 1974. Activity and Movement Patterns in a Population of Fowler's Toad, Bufo woodhousei fowleri. American Midland Naturalist 92:257-274.

Conant, R. and J. T . Collins. 1998. Reptiles and Amphibians of Eastern and Central North America. Third Edition, Expanded. Houghton Mifflin, New York, NY.

Frost, D. R., T. Grant, J. Faivovich, R. H. Bain, A. Haas, C. F. Haddad, R. O. De Sa, A. Channing, M. Wilkinson, S. C. Donnellan, and C. J. Raxworthy. 2006. The amphibian tree of life. Bulletin of the American Museum of Natural History:1-291.

Klueh, S., J. Mirtl, and T. Shier. 2011. Anaxyrus fowleri. Fowler's Toad. Geographic distribution. Herpetological Review 42:236.

Klueh, S. and J. Mirtl. 2010. Anaxyrus fowleri. Fowler's Toad. Geographic distribution. Herpetological Review 41:374-375.

Masta, S. E., B. K. Sullivan, T. Lamb, and E. J. Routman. 2002. Molecular Systematics, Hybridization, and Phylogeography of the Bufo americanus Complex in Eastern North America. Molecular Phylogenetics and Evolution 24:302-314

Minton, S. A. Jr. 2001. Amphibians and Reptiles of Indiana. Indiana Academy of Science, Indianapolis, IN.

Pauly, G.B., D. M. Hillis, and D. C. Cannatella. 2009. Taxonomic freedom and the role of official lists of species names. Herpetologica 65:115-128.

Pierson, T. 2012. Anaxyrus fowleri. Fowler's Toad. Geographic distribution. Herpetological Review 43:297.

Timm, A. and V. Meretsky. 2011. Anuran Habitat use on Abandoned and Reclaimed Mining Areas of Southwestern Indiana. Proceedings of the Indiana Academy of Science 113:140-146.

Distribution Map
Distribution map of Fowler's Toad (Bufo fowleri)
Photographs