Hyla chrysoscelis
Encyclopedia
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 Appalachian
s (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).
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 chromosome
s 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.
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.
The species name chrysoscelis is from Greek chrysos gold and scelis leg.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of tree frog
Tree frog
Hylidae is a wide-ranging family of frogs commonly referred to as "tree frogs and their allies". However, the hylids include a diversity of frog species, many of which do not live in trees, but are terrestrial or semi-aquatic.-Characteristics:...
which is found in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. 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
Piedmont (United States)
The Piedmont is a plateau region located in the eastern United States between the Atlantic Coastal Plain and the main Appalachian Mountains, stretching from New Jersey in the north to central Alabama in the south. The Piedmont province is a physiographic province of the larger Appalachian division...
and Coastal Plain
Atlantic Coastal Plain
The Atlantic coastal plain has both low elevation and low relief, but it is also a relatively flat landform extending from the New York Bight southward to a Georgia/Florida section of the Eastern Continental Divide, which demarcates the plain from the ACF River Basin in the Gulf Coastal Plain to...
of Virginia and the Carolinas. In those areas, H. versicolor may be present only in the Appalachian
Appalachian Mountains
The Appalachian Mountains #Whether the stressed vowel is or ,#Whether the "ch" is pronounced as a fricative or an affricate , and#Whether the final vowel is the monophthong or the diphthong .), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians...
s (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).
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
, for instance moths of the genus Catocala
Catocala
Catocala is a genus of noctuid moths commonly known as Underwings. Most species have brightly coloured underwings, orange, red, or white. The genus name is a combination of two Greek words, kato behind, and kalos beautiful...
(Sargent 1969). Both species of Gray Tree Frogs are slightly sexually dimorphic
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
. Males have black or gray throats in the breeding season, while the throat of the female is lighter (Tyning 1990).
Microscopic inspection of the chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
s of each species reveals that H. versicolor has an extra set. H. chrysoscelis is what is called diploid
Ploidy
Ploidy is the number of sets of chromosomes in a biological cell.Human sex cells have one complete set of chromosomes from the male or female parent. Sex cells, also called gametes, combine to produce somatic cells. Somatic cells, therefore, have twice as many chromosomes. The haploid number is...
, having two complete sets of chromosomes, the usual condition in vertebrates. Hyla versicolor is tetraploid
Polyploidy
Polyploid is a term used to describe cells and organisms containing more than two paired sets of chromosomes. Most eukaryotic species are diploid, meaning they have two sets of chromosomes — one set inherited from each parent. However polyploidy is found in some organisms and is especially common...
, having double the usual number of chromosomes. It is generally believed that H. versicolor evolved from H. chrysoscelis in the last major ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
, when areas of extremely low temperature divided populations. Despite currently sharing habitat, the two species generally do not interbreed.
Hyla chrysoscelis is capable of surviving temperatures as low as -8°C.
The species name chrysoscelis is from Greek chrysos gold and scelis leg.
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.