Eastern Gray Treefrog
|Taxonomic Notes: Duellman et al. (Zootaxa 2016) treated two major clades as genera; AmphibiaWeb treats these two clades as subgenera(Hyla in the Old World; Dryophytes in the New World and East Asia), thus stabilizing traditional taxonomy.|
© 2007 John White (1 of 54)
Males 32-51 mm, females 33-60 mm (Wright and Wright 1949). In general, these frogs have warty skin and prominent adhesive pads on their fingers and toes (Johnson 1987). Their color can vary from green to light green-gray, gray, brown or dark brown (Johnson 1987). Usually, a large irregular star or spot appears on the back (Wright and Wright 1949) A large white spot is always present below each eye (Johnson 1987), although it is less visible and more of an olive color in females (Wright and Wright 1949). The belly is white (Johnson 1987). Males have pale flesh-colored vocal sacs (Wright and Wright 1949). In males, the chin is similar to the belly, with blackish spots (Wright and Wright 1949). In males, the legs are yellow or orange-yellow ventrally. (Johnson 1987), whereas in females, the back of the forelegs, hindlegs and sides are a pale olive gray (Wright and Wright 1949).
The tadpole is approximately 50 mm long, with a long tail. The coloration is scarlet or orange vermilion with black blotches around the edge of the crests (Wright and Wright 1949).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Canada, United States
U.S. state distribution from AmphibiaWeb's database: Connecticut, District of Columbia, Delaware, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, Mississippi, North Carolina, North Dakota, New Hampshire, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Dakota, Tennessee, Texas, Virginia, Vermont, Wisconsin, West Virginia
Canadian province distribution from AmphibiaWeb's database: Manitoba, New Brunswick, Ontario, Quebec
In Canada, the frog occurs in southern Quebec, southern, central and northwestern Ontario and south-eastern and central Manitoba. There is also an isolated population in Fredericton, New Brunswick (Cook 1984).
This treefrog is found in small wood lots, in trees along prairie streams, in large tracks of mixed hardwood forest, and in the bottomland forests along rivers and swamps(Johnson 1987).Hyla versicolor has been observed living in the tree canopies as high as 20.5 meters above ground. It is speculated that the frog is utilizing cooler, wetter micro-habitats in the mid-canopy region of the forest.
Life History, Abundance, Activity, and Special Behaviors
Breeding season begins at the end of April and ends in August, with breeding events typically concentrated during spring rains in May and June (Oldfield and Moriarty 1994). The female lays approximately 30 to 40 eggs of a brown and cream or yellow color in small scattered masses or packets on the surface of quiet pools. The eggs, measuring about 1.1-1.2 mm, are attached to the vegetation. Hatching occurs at 4-5 days (Wright and Wright 1949).
This frog is freeze-tolerant (Schmid 1982; Storey and Storey 1985).
Hyla versicolor has been found to be significantly less prone to infection by the trematode parasite Ribeiroia ondatrae than the sympatric species Bufo americanus, with metamorphic treefrogs harboring far less of a trematode parasite load and little associated mortality or deformities. H. versicolor may have higher immunity to this parasite (Johnson and Hartson 2009).
Trends and Threats
H. versicolor is one of the frog species which has been used to demonstrate the insufficiency of many of the pesticide studies conducted by pesticide manufacturers under current EPA regulations. H. versicolor tadpoles are susceptible to mortality from exposure to low concentrations of the pesticide carbaryl, with 10-60% of carbaryl-exposed tadpoles dying in laboratory experiments. This mortality rate shoots up to 60-90% if the tadpoles are simultaneously exposed to both stress and low concentrations of carbaryl, with stress induced experimentally by placing a caged predator in the water (Relyea and Mills 2001). Thus studies examining only low concentrations of pesticide without considering synergistic effects from other factors may be highly likely to underestimate the negative effects of the pesticide.
Perhaps the most striking feature of this frog is its ability to change color to match its environment (metachrosis) - a process which usually requires about half an hour (Logier 1952).
This species was featured as News of the Week on 25 September 2017:
Hyla versicolor has long been known to use tree canopies. However, Laughlin et al. (2017) recently discovered that the treefrogs use natural habitats much higher than previously recorded, more than 12 meters above ground. The authors initially set up passive-infrared sensor camera traps to study white pine (Pinus strobus) canopy ecology but unexpectedly captured night images of H. versicolor at 18 meters high on four separate occasions over 14 months. The images of H. versicolor were always associated with southern flying squirrels (Glaucomys volans), which were more likely to be sensed by the cameras than the small ectothermic frogs. During that time, the researchers also directly observed another H. versicolor individual during a summer day at 20.5 meters. The researchers speculate that the frogs are utilizing cooler, wetter microhabitats in the mid-canopy that allow them to maintain these heights during the day and at night. These observations highlight the need for natural history information on H. versicolor and on the non-breeding habitats and behavior of amphibians in general (Written by Ann T. Chang).
This species was featured as News of the Week on 9 November 2020:
The physical properties of our environments greatly affects how all organisms interact with the physical world. The surface tension of water is no exception. Schwenk and Phillips (2020) show that surface tension can actually prevent small tadpoles from breaching the surface of water to breathe air. Instead, tadpoles perform a newly described form of air-breathing they call "bubble-sucking", during which tadpoles carefully suck down a bubble from the water’s surface. As tadpoles grow, they are eventually able to overcome this constraint and begin breaching the surface to breathe. Phillips et al. (2020) report that Gray Treefrog tadpoles (Hyla versicolor) do not follow these trends, and instead bubble-suck throughout ontogeny, even after they are large enough to breach the surface. They found that tree frog tadpoles not only never breach, but after growing to a certain size, begin breathing with a novel form of bubble-sucking the authors coin "double bubble-sucking". Double bubble-sucking includes an extra breathing cycle which appears to greatly increase the efficiency of air-breathing by separating freshly breathed air from the residual air already in the lungs. The authors find that tree frog tadpoles transition from normal bubble-sucking to double bubble-sucking at the same body size that the lungs suddenly become well-vascularized, suggesting the change in breathing mechanics is linked to a change from non-respiratory air-breathing to respiratory air-breathing. Check out media coverage of these articles in Sciencedaily and Popular Science. To learn more about tadpoles, see the 1st International Symposium on Tadpole Evolution, this week Nov 11-13th (Written by Jack Phillips).
Bartlett, R. D., and Bartlett, P. P. (1999). A Field Guide to Texas Reptiles and Amphibians. Gulf Publishing Company, Houston, Texas.
Conant, R. and Collins, J. T. (1991). A Field Guide to Reptiles and Amphibians: Eastern/Central North America. Houghton Mifflin, Boston.
Cook, F. R. (1984). Introduction to Canadian Amphibians and Reptiles. National Museums of Canada, Ottawa, Canada.
Johnson, J. R., and Semlitsch, R. D. (2003). ''Defining core habitat of local populations of the Gray Treefrog (Hyla versicolor) based on choice of oviposition sites.'' Oecologica, 137, 205-210.
Johnson, P. T. J., and Hartson, R. B. (2008). ''All hosts are not equal: explaining differential patterns of malformations in an amphibian community.'' Journal of Animal Ecology, 78, 191-201.
Johnson, T.R. (1977). The Amphibians of Missouri. University of Kansas Publications, Lawrence, KS.
Laughlin, M.M., Olson, E.R., Martin, J.G. (2017). Arboreal camera trapping expands Hyla versicolor complex (Hylidae) canopy use to new. Ecology, 98(8), 2017, pp. 2221–2223 DIO: 10.1002/ecy.1843
Logier, E. B. S. (1952). The Frogs, Toads and Salamanders of Eastern Canada. Clarke, Irwin & Company Ltd., Canada.
Matson, T. O. (1990). ''Erythrocyte size as a taxonomic character in the identification of Ohio Hyla chrysoscelis and H. versicolor.'' Herpetologica, 46, 457-462.
Oldfield, B. and Moriarty, J. J. (1994). Amphibians and Reptiles Native to Minnesota. University of Minnesota Press, Minneapolis.
Relyea, R. A., and Mills, N. (2001). ''Predator-induced stress makes the pesticide carbaryl more deadly to grey treefrog tadpoles (Hyla versicolor) .'' Proceedings of the National Academy of Sciences, 98, 2491-2496.
Schmid, W. D. (1982). ''Survival of frogs in low temperature.'' Science, 215, 697-698.
Wright, A. H. and Wright, A. A. (1949). Handbook of Frogs and Toads of the United States and Canada. Comstock Publishing Company, Inc., Ithaca, New York.
Originally submitted by: Theresa Ly (first posted 2001-05-09)
Edited by: Kellie Whittaker, Ann T. Chang (2020-11-16)
Species Account Citation: AmphibiaWeb 2020 Hyla versicolor: Eastern Gray Treefrog <https://amphibiaweb.org/species/989> University of California, Berkeley, CA, USA. Accessed Jul 4, 2022.
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Citation: AmphibiaWeb. 2022. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 4 Jul 2022.
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