Hyla chrysoscelis

Cope's Grey Tree Frog
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Family:	Hylidae
Genus:	Hyla
Species:	H. chrysoscelis
Binomial name
Hyla chrysoscelis Cope, 1880

The Cope's Grey Tree Frog (Hyla chrysoscelis) is a species of tree frog which is found in the United States. It is almost indistinguishable from the Grey Tree Frog, Hyla versicolor, and shares much of its geographic range. Both species are variable in color, mottled gray to gray-green, resembling the bark of trees. These are tree frogs of woodland habitats, though they will sometimes travel into more open areas to reach a breeding pond. The only readily noticeable difference between the two species is the call--Cope's has a faster paced, and slightly higher pitched, call than H. versicolor. In addition, H. chrysoscelis is reported to be slightly smaller, more aboreal, and more tolerant of dry conditions than H. versicolor (Martof et al., 1980). The range of H. chrysoscelis is more southerly--it is apparently the species found in the lower elevation Piedmont and Coastal Plain of Virginia and the Carolinas. In those areas, H. versicolor may be present only in the Appalachians (Martof et al. 1980). The Bird-voiced Tree Frog, Hyla avivoca, is similar to Hyla chrysoscelis/versicolor, but is smaller (25-50 mm length, vs. 32-62 mm for the Grey Tree Frogs).

hind leg

Both Hyla chrysoscelis and Hyla versicolor have bright orange patches on the hind legs, which distinguishes them from other tree frogs, such as Hyla avivoca (Martof et al. 1980). The bright yellow pattern is normally hidden, but exposed when the frog leaps (Univ. Maine, Frogs and Toads of Ohio). This "flash pattern" likely serves to startle a predator as the frog makes its escape (Exploratorium). Similar hidden bright patters are common in various lepidoptera, for instance moths of the genus Catocala (Sargent 1969). Both species of Gray Tree Frogs are slightly sexually dimorphic. Males have black or gray throats in the breeding season, while the throat of the female is lighter (Tyning 1990).

Microscopic inspection of the chromosomes of each species reveals that H. versicolor has an extra set. H. chrysoscelis is what is called diploid, having two complete sets of chromosomes, the usual condition in vertebrates. Hyla versicolor is tetraploid, having double the usual number of chromosomes. It is generally believed that H. versicolor evolved from H. chrysoscelis in the last major ice age, when areas of extremely low temperature divided populations. Despite currently sharing habitat, the two species generally do not interbreed.

Showing variation in color

In the Southeastern United States, Cope's Grey Tree Frog breeds and calls from May to August. Isolated males start calling from woodland areas during warm weather a week or more before migrating to temporary ponds to breed. There they form aggregations (choruses) and call together. Chorusing is most frequent at night, but individuals often call during daytime in response to thunder or other loud noises. Eggs are laid in batches of ten to forty on the surface of shallow ponds and other small bodies of water. These are usually temporary bodies of water lacking fish. Eggs hatch in approximately five days and metamorphosis takes place at about 45-65 days. (Tyning 1990, Martof et al. 1980, Atlanta's Backyard Herps).

Hyla chrysoscelis is capable of surviving temperatures as low as -8°C.^[1]

The species name chrysoscelis is from Greek chrysos gold and scelis leg.^[2]

See also

• Grey Tree Frog, Hyla versicolor. Most details of life history of the two species are similar, so see that account for more information.

References

1. ^ Adaptations of Frogs to Survive Freezing
2. ^ Family Group Names in Diptera

• Hammerson (2004). Hyla chrysoscelis. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 12 May 2006. Database entry includes a range map and justification for why this species is of least concern
• Amphibiaweb--accessed 1 June 2006
• Animal Diversity Web: Hyla versicolor & Hyla chrysoscelis
• Atlanta's Backyard Herps--accessed 8 May 2006
• Univ. Maine Wetland Connections--accessed 11 May 2006
• Frogs and Toads of Ohio--accessed 11 May 2006
• Exploratorium: Amazing Adaptable Frog--accessed 11 May 2006
• IUCN--Global Amphibian Assessment, accessed 1 June 2006
• NatureServe--conservation status, accessed 1 June 2006
• Bernard S. Martof et al. (1980). Amphibians and Reptiles of the Carolinas and Virginia. Chapel Hill: University of North Carolina Press. ISBN 0-8078-4252-4.
• Sargent (1969). A suggestion regarding hindwing diversity among moths of the genus Catocala OF (Noctuidae). Journal of the Lepidopterists' Society 23: 261-264. (Available here.)
• Thomas F. Tyning (1990). A Guide to Amphibians and Reptiles. Boston: Little, Brown and Company. ISBN 0-316-81719-8.