Monday, June 8, 2020

Episode 528 (6-8-20): The Distinction of Gray Treefrogs, Plus a Cicada Closing

Click to listen to episode (3:58)

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 6-5-20.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of June 8, 2020.

SOUND – ~5 sec – Gray Treefrog

This week, we have a trilling episode.  That is, we feature the different trilling calls of two frog species that are indistinguishable to the naked eye.  Have a listen for about 20 seconds to the two species’ male breeding calls, and see if you know these two kinds of frogs.  And here’s a hint: think of tall woody plants and then the color of a rainy sky.

SOUNDS - ~19 sec

If you guessed treefrogs, you’re on the right track.  And if knew that the first call was the Gray Treefrog and the second was Cope’s Gray Treefrog, you’re a frog-call phenom!  The two frog species look identical, but they don’t interbreed and they differ in the number of chromosomes in their cells.  In Virginia they have somewhat different ranges, with the Gray Treefrog typically found in about the middle half of the Commonwealth and Cope’s Gray Treefrog primarily found in the Coastal Plain and the far southwest.  Those male breeding calls you heard are the usual way of distinguishing the two species.

As their name implies, these amphibians live mostly in trees or shrubs, except during their spring and summer breeding season when they move to shallow, standing waters to mate.  Both species are relatively small, from about one to three inches long; both feed on various insects and other invertebrates; and both are colored gray, green, brown, or white, except for orange or yellow marks on their hind legs.

Thanks to the Virginia Department of Game and Inland Fisheries and to Lang Elliott’s NatureSound Studio for permission to use the Cope’s Gray Treefrog sounds, from the 2008 CD, “The Calls of Virginia Frogs and Toads.”

We close this week with an extra sound, one that doesn’t have anything to do with frogs or even particularly with water, but results from a natural event occurring in southwestern Virginia this late spring that’s too unusual not to mention, and too loud not to notice.  That’s the 2020 emergence of Brood IX of the 17-year periodical cicada, bringing with it a chorus of mating calls by the male insects.  Have a listen for about 10 seconds to that sound, recorded on a mountain trail near Blacksburg on June 4.

SOUND - ~11 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 Cope’s Gray Treefrog 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 (VDGIF) and Lang Elliott/NatureSound Studio, used with permission.  For more information on this CD, contact VDGIF online at; by mail to P.O. Box 90778, Henrico, VA 23228-0778; by phone to (804) 367-1000 (VTDD); or by e-mail to

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

The Gray Treefrog sounds were recorded by Virginia Water Radio at a seasonal pond in Heritage Park in Blacksburg, Va., on July 8, 2016, about 9 p.m.  The sounds in the background are the “peep” of Spring Peepers and the “thunk” of Green Frogs.

The periodical cicada sounds were recorded by Virginia Water Radio on Brush Mountain just north of Blacksburg, Virginia, on June 4, 2020, about 12 noon.

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


Gray Treefrog in a pond at a residence in Blacksburg, Va., April 30, 2007.

Cope’s Gray Treefrog, photographed in Chesapeake, Virginia, July 8, 2019.  Photo by David Weisenbeck, made available on iNaturalist at (as of 6-8-20) for use under Creative Commons license “Attribution-NonCommercial 4.0.”  Information about this Creative Commons license is available online at

Virginia range maps for the Gray Treefrog (upper) and Cope’s Gray Treefrog (lower). Maps taken from the Virginia Department of Game and Inland Fisheries, “Fish and Wildlife Information Service,” online at  The Gray Treefrog map is online at; the Cope’s Gray Treefrog map is online at

Periodical cicada, photographed in Patrick County, Va., June 7, 2020.  Photo by Kathy Richardson, made available on iNaturalist at (as of 6-8-20) for use under Creative Commons license “Attribution-NonCommercial 4.0.”  Information about this Creative Commons license is available online at


The scientific name of Gray Treefrog is Hyla versicolor.

The scientific name of Cope’s Gray Treefrog in Hyla chrysoscelis.

The following information is quoted from the Virginia Department of Game and Inland Fisheries, “Fish and Wildlife Information Service,” online at for the Gray Treefrog and at for Cope’s Gray Treefrog.

Gray Treefrog

Physical Appearance
“Usually gray but coloration ranges from gray to whitish to brown to green, dependent upon environment and activities.  There is a whitish mark beneath the eyes and a bright orange or yellow on the concealed surfaces of the hind legs.  This species ranges in length from 32 to 62 mm (1.25-2.5 in).”

“Males call between March and August.  The call of this species is a slower trill than that of Cope’s Gray Treefrog, 25 trills per second.  Breeding generally occurs from March to June.  The female lays clumps of 10 to 40 eggs per group on the surface of shallow ditches, puddles, and ponds.   Females may lay more than one clutch in a season…. Eggs typically hatch in 4 to 5 days, and metamorphosis occurs in 45 to 64 days.”

“This species is not often seen on the ground or near the water's edge except during the breeding season.  It tends to forage while in small trees or shrubs near to or in standing water.  This species is an opportunistic feeder focusing primarily on larval Lepicoptera [butteflies and moths], Coleoptera [beetles], and other arthropods.”

Aquatic/Terrestrial Associations
“This species is typically associated with the following forest types: black willow, sweet gum-willow oak, white oak-red oak-black oak and mixed pine-hardwood.  They are frequently found in recently disturbed areas with shrub and herbaceous cover.”

Cope’s Gray Treefrog

Physical Appearance
“This species is identical to [Gray Treefrog] in appearance but they do not interbreed.  The two gray treefrog species can be distinguished genetically and by breeding call…. The male mating call of Cope’s Gray Treefrog is shorter, harsher and more forceful than [Gray Treefrog].  It is a faster call averaging 45 trills/second.  This species is generally slightly smaller than [Gray Treefrog].

“This species breeds between May and August and is usually not found outside of this period. ..Females lay scattered clumps of 10 to 40 eggs on the surfaces of shallow ditches and small ponds.  These eggs hatch in 4 or 5 days.  Metamorphosis occurs in 45 to 64 days…. This species may have two clutches per season.”

“This species is more arboreal and is more tolerant of low humidity than [Gray Treefrog.].  Its diet consists of insects which are foraged from trees, shrubs, and off the ground preferably near water.  This species is an opportunistic feeder.  Typical prey items include larval Lepidoptera [butterflies and moths], Coleoptera [beetles], and other arthropods.”

Aquatic/Terrestrial Associations
“This species is typically associated with small ponds, ditches, beaver ponds, or other standing water.  It is frequently found in areas that have been recently disturbed but contain shrubs, herbaceous vegetation, and/or vines.”


Used for Audio

Eric Day et al., “Periodical Cicada,” Virginia Cooperative Extension Publication 444-276 (ENTO-105NP), February 25, 2015, online at

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.  [This is the source used for the description included in the audio/transcript of the two frog species' ranges.]

Lang Elliott, The Calls of Frogs and Toads, Stackpole Books, Mechanicsburg, Penn., 2004.

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

Dan Mozgai, “Cicada Mania,” online at  Information on periodical cicada Brood IX and its emergence in 2020 is online at

James Mason, “What’s that noise? The 17-year cicadas are back,” Virginia Tech Daily, May 2020, online at

Robert Powell et al., Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition, Houghton Mifflin Harcourt, Boston and New York, 2016.

Virginia Department of Game and Inland Fisheries, “Fish and Wildlife Information Service,” online at
The Gray Treefrog entry is online at
The Cope’s Gray Treefrog entry is online at

Virginia Herpetological Society, online at  Herpetology is the study of amphibians and reptiles.
The Gray Treefrog entry is online at
The Cope’s Gray Treefrog entry is online at
Information on all frogs and toads in Virginia is online at
The “Frog Calling Schedule” is online (as a PDF) at

For More Information about Frogs and Other Amphibians

AmphibiaWeb, “Order Anura—Frogs and Toads Species List,” online at

FrogWatch USA, online at  According to this Web site, this is the American Zoological Association (AZA)'s citizen science program and “encourages volunteers to collect and contribute information about the breeding calls of frogs and toads to a national dataset that is publicly available online.”

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

For More Information about Periodical Cicadas

Ralph Berrier (text) and Stephanie Klein-Davis (photos), Watch Now: The 17-year cicadas emerge across Southwest Virginia, Roanoke Times, 6/8/20.


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

Following are links to other episodes on featuring sounds of the Gray Treefrog.

Episode 371, 6-5-17 – Herp Blitz by Virginia Herpetological Society (sounds of Bullfrog, Gray Treefrog, Northern Cricket Frog, Fowler's Toad, and Green Frog).
Episode 408, 2-19-18 – Frog and Toad Medley (sounds of American Toad, Bullfrog, Carpenter Frog, Gray Treefrog, Green Frog, Mountain Chorus Frog, Northern Cricket Frog, Pickerel Frog, Spring Peeper, and Wood Frog).
Episode 427, 7-2-18 – a July 4th “debate.”
Episode 431, 7-30-18 – on the Tazewell County, Va., community of Frog Level (sounds of Gray Treefrog, Green Frog, and Spring Peeper).
Episode 524, 5-11-20 – a sampler of animal sounds.


Following are some Virginia Standards of Learning (SOLs) that may be supported by this episode’s audio/transcript, sources of information, or other materials in the Show Notes.

2010 Science SOLs

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

Grades K-6 Life Processes Theme
K.7 – basic needs and processes of plants and animals.
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.
3.5 – food webs.
3.6 – ecosystems, communities, populations, shared resources.
5.5 – cell structures and functions, organism classification, and organism traits.

Life Science Course
LS.4 – organisms’ classification based on features.
LS.8 – community and population interactions, including food webs, niches, symbiotic relationships.
LS.9 – adaptations for particular ecosystems’ biotic and abiotic factors, including characteristics of land, marine, and freshwater environments.

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.

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.
Episode 483, 7-29-19 – on buoyancy and drag, for middle school and high school.
Episode 524, 5-11-20 – on sounds by water-related animals, for elementary school through high school.