Monday, July 22, 2019

Episode 482 (7-22-19): A Short Tale of Two Coastal Plain Toads

Click to listen to episode (4:09)

Sections below are the following:
Transcript of Audio
Audio Notes and Acknowledgments
Extra Information
Related Water Radio Episodes
For Virginia Teachers (Relevant SOLs, etc.).

Unless otherwise noted, all Web addresses mentioned were functional as of 7-19-19.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of July 22, 2019.

This week, we explore some likenesses and differences between to summertime sound-makers found in the Commonwealth’s southeastern Coastal Plain.  Have a listen for about 15 seconds to the following mystery sounds, and see if you know these two species of amphibian.  And here’s a hint: if you look below the Mason-Dixon line in a tall tree, you might totally get this question.

SOUNDS - ~17

If you guessed the Southern Toad and the Oak Toad, you get a Virginia amphibian A+!  These are two of four Virginia species in the scientific family considered “true toads.”  In Virginia, both the Southern and Oak toads occur essentially only in the southeastern corner, they breed from spring through September, and they show a preference for wooded areas with sandy soils.  Like Virginia’s other two true toads—American and Fowler’s—the Southern and Oak toads are in the scientific gemus of Anaxyrus, Latin for “king” or “chief.”

Beyond these similarities, though, these two species show marked differences.  The Southern Toad’s full scientific name is Anaxyrus terrestris, meaning “king of the earth,” while the Oak Toad is Anaxyrus quercicus, a much more modest “king of the oak leaves.”  Earlier you heard the obvious difference in the species’ male breeding calls—the long trill of the Southern Toad compared to the chick-like peep of the Oak Toad.  The calls parallel the animals’ size difference: the Southern Toad is about 2-4 inches long, while the approximately 1-inch-long Oak Toad is the smallest toad species in North America.  The Southern Toad hides during the day and begins to forage for food at dusk, while the Oak Toad is more active in daytime.  Finally, the Southern Toad is considered the most common toad species in southeastern Virginia and the southern United States, while the Oak Toad is considered by Virginia wildlife specialists to be rare and of special concern in the Commonwealth.

Exploring living things often reveals striking differences beyond surface similarities.  That’s a tale re-told by two Virginia Coastal Plain toads.

Thanks to the Virginia Department of Game and Inland Fisheries and to Lang Elliott for permission to use this week’s sounds, from the 2008 CD, “The Calls of Virginia Frogs and Toads.”  We close with one more round of the Southern Toad, with the “thunk” sounds of Green Frogs in the background.

SOUNDS - ~10 sec


Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment.  For more Virginia water sounds, music, or information, visit us online at, or call the Water Center at (540) 231-5624.  Thanks to Stewart Scales for his banjo version of Cripple Creek to open and close this show.  In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.

The sounds in this episode were from “The Calls of Virginia Frogs and Toads” CD, copyright 2008 by the Virginia Department of Game and Inland Fisheries and Lang Elliott/NatureSound Studio, used with permission.  For more information on this CD, visit (as of July 19, 2019, the item was out of stock), or contact the Department at P.O. Box 90778, Henrico, VA 23228-0778; phone: (804) 367-1000 (VTDD); e-mail:; main Web site:

Lang Elliott’s work is available online at the “Music of Nature” Web site,

Click here if you’d like to hear the full version (1 min./11 sec.) of the “Cripple Creek” arrangement/performance by Stewart Scales that opens and closes this episode.  More information about Mr. Scales and the group New Standard, with which Mr. Scales plays, is available online at


Southern Toad in South Carolina in 2012. Photo by Mark Musselman, made available for public use by the U.S. Fish and Wildlife Service's National Digital Library, online at; specific URL for the photo is

Oak Toad. Photo by Matthew Niemiller, made available on iNaturalist, online at, for under Creative Commons License BY-NC; for more on that attribution category, visit

Above are Virginia county occurrence maps for the Southern Toad and Oak Toad in Virginia, from the Virginia Department of Game and Inland Fisheries (VDGIF), “Wildlife Information,” online at, accessed 7/19/19.


“True toads” are in the Amphibian family Bufonidae.

The scientific name for the Southern Toad is Anaxyrus terrestris; for the Oak Toad, Anaxyrus quercicus.

Following is information on these two species quoted from the Virginia Department of Game and Inland Fisheries, “Fish and Wildlife Information Service,” online at for Southern Toad and for Oak Toad.

Southern Toad

Physical Characteristics
“This toad is generally a brown color, but may vary in color from red or gray to black.  The crests on head are prominent and they are raised at the rear into clublike knobs.  The skin between the larger warts is finely roughened with tubercles all over, including the eyelids.  There may be a light mid-dorsal stripe. This toad grows to lengths of 1 5/8 – 3 in. (4.1 – 7.5 cm.).  This species breeds from March to September.  The eggs are in long coils of jelly, and are 1/25-1/16 inch in diameter and 2500-3000 in number.  The eggs hatch in 2-4 days.  The tadpoles are black, with a short rounded tail, and tooth ridges 2/3.  The transformation occurs in 30-55 days.  The voice is a shrill musical trill.”

“This is the most common toad of the southern U.S, occurring in Virginia only in the southeastern piedmont and coastal plain. It is abundant in areas with sandy soils.  This species breeds in any shallow freshwater and may lay eggs in pools so transient that they last only a few hours, resulting in hatching failure.”

“This species forages at night.  Food preferences are not documented for this species but it is assumed that it eats insects.”

Oak Toad

Physical Characteristics
“This species is small, with a length from 3/4-1 5/16 in. (1.9-3.3 cm.).  It has a conspicuous light mid-dorsal stripe that may be white, cream, yellow, or orange and 4-5 pairs of spots on the back.  It is black or brown in color and the skin is finely roughened with tubercles (small bumps), many of which are red.  The male vocal sac is conspicuous when deflated, and looks like a triangular apron, with the point extending backward over the pectoral region.  The tadpoles are grayish with 6-7 black saddles on the musculature and with a heavily marked upper tail crest.  This species breeds from April to September.  The eggs are laid in bars of 2-5 eggs.  This species breeds in shallow ponds following heavy rain.  The voice is like the peeping of newly hatched chicks, but at close range is extremely loud.”

“This species is known from six sites in five counties of Virginia’s Coastal Plain from Virginia south through Florida and west to the Mississippi.  The oak toad breeds in shallow pools, ditches, and ponds. Habitats used during other seasons are associated with pine or oak savannas with sandy soils. Unique habitat features include vernal pools and freshwater wetlands (pocosins).”

“The diet is unknown for Virginia, but individuals from Florida and Georgia consumed various terrestrial insects and arthropods.”


Used for Audio

John D. Kleopfer and Chris S. Hobson, A Guide to the Frogs and Toad of Virginia, Special Publication Number 3, Virginia Department of Game and Inland Fisheries, Richmond, 2011.

Bernard S. Martof, et al., Amphibians and Reptiles of the Carolinas and Virginia, University of North Carolina Press, Chapel Hill, 1980.

J.C. Mitchell and K.K. Reay, Atlas of Amphibians and Reptiles in Virginia, Virginia Department of Game and Inland Fisheries/Richmond (1999); available online (as a PDF) at, courtesy of the Virginia Herpetological Society.   (Herpetology refers to the study of amphibians and reptiles.)

New Hampshire PBS, “Wildlife Journal Junior/True Toads,” online at

Virginia Department of Game and Inland Fisheries, “Wildlife Information,” online at This site has summaries of characteristics, distribution, and foods for a list of species. The summary information for the two toad species in covered in this episode found in Virginia is at the following links:
Southern Toad;
Oak Toad.

Virginia Department of Game and Inland Fisheries, “Virginia Fish and Wildlife Information Service,” online at This site has detailed information on life history, distribution, habitat, and other aspects of species. The detailed information for the two species in this episode is at the following links:
Southern Toad;
Oak Toad.

Virginia Herpetological Society, “Frogs and Toads of Virginia,” online at  Information on the two toads covered in this episode is at the following links:
Southern Toad;
Oak Toad.

Virginia Herpetological Society, “What Frogs Are You Hearing?” online (as a PDF) at

For More Information about Toads or Other Amphibians


U.S. Geological Survey (USGS), “National Amphibian Research and Monitoring Initiative,” online at

Virginia Department of Game and Inland Fisheries, “Virginia Frog and Toad Calling Survey,” online at; part of the North American Amphibian Monitoring Program, online at

Virginia Department of Game and Inland Fisheries, “Virginia is for Frogs” Web site, online at


All Water Radio episodes are listed by category at the Index link above (   See particularly the “Amphibians” subject category.

Following are links to previous episodes on toads.

Episode 413, 3/26/18 – American Toad.
Episode 424, 6/11/18 – Fowler’s Toad.


The episode—the audio, extra information, or sources—may help with the following Virginia Standards of Learning (SOLs).

2010 Science SOLs

Grades K-6 Earth Resources Theme
4.9 – Va. natural resources, including watersheds, water resources, and organisms.

Grades K-6 Life Processes Theme
1.5 – animals’ basic needs and distinguishing characteristics.
2.4 – life cycles.
3.4 – behavioral and physiological adaptations.

Grades K-6 Living Systems Theme
2.5 – living things as part of a system, including habitats.
3.6 – ecosystems, communities, populations, shared resources.
6.7 – natural processes and human interactions that affect watershed systems; Va. watersheds, water bodies, and wetlands; health and safety issues; and water monitoring.

Life Science Course
LS.1 – understanding of scientific reasoning, logic, and the nature of science, including current applications to reinforce science concepts.
LS.4 – organisms’ classification based on features.
LS.8 – community and population interactions, including food webs, niches, symbiotic relationships.

Biology Course
BIO.1 – current applications to reinforce science concepts.
BIO.6 – bases for modern classification systems, including structures, biochemistry, and developmental stages.
BIO.8 – dynamic equilibria and interactions within populations, communities, and ecosystems; including nutrient cycling, succession, effects of natural events and human activities, and analysis of the flora, fauna, and microorganisms of Virginia ecosystems.

2015 Social Studies SOLs

Civics and Economics Course
CE.7 – government at the state level.
CE.10 – public policy at local, state, and national levels.

Government Course
GOVT.8 – state and local government organization and powers.
GOVT.9 – public policy process at local, state, and national levels.

Virginia’s SOLs are available from the Virginia Department of Education, online at

Following are links to Water Radio episodes (various topics) designed especially for certain K-12 grade levels.

Episode 250, 1-26-15 – on boiling, for kindergarten through 3rd grade.
Episode 255, 3-2-15 – on density, for 5th and 6th grade.
Episode 282, 9-21-15 – on living vs. non-living, for kindergarten.
Episode 309, 3-28-16 – on temperature regulation in animals, for kindergarten through 12th grade.
Episode 333, 9-12-16 – on dissolved gases, especially dissolved oxygen in aquatic habitats, for 5th grade.
Episode 403, 1-15-18 – on freezing and ice, for kindergarten through 3rd grade.
Episode 404, 1-22-18 – on ice on ponds and lakes, for 4th through 8th grade.
Episode 406, 2-5-18 – on ice on rivers, for middle school.
Episode 407, 2-12-18 – on snow chemistry and physics, for high school.