Grey tree frog
Encyclopedia
The Gray Treefrog or Gray Tree Frog, is a species
of small arboreal frog
native to much of the eastern United States
and southeastern Canada
.
It is sometimes referred to as the Eastern Gray Treefrog, Common Gray Treefrog, or Tetraploid Gray Treefrog to distinguish it from its more southern genetically disparate cousin, the Cope's Gray Treefrog (Hyla chrysoscelis
). It may sometimes be referred to as the North American Tree Frog by Europeans to distinguish it from their European Tree Frog
(Hyla arborea).
As the scientific name implies, Gray treefrogs are variable in color owing to their ability to camouflage
themselves from gray to green, depending on the substrate they are sitting on. The degree of mottling varies. They can change from nearly black to nearly white. They change color at a slower rate than a chameleon
. Dead Gray Treefrogs and ones in unnatural surroundings are predominantly gray.
They are relatively small compared to other North American frog species, typically attaining no more than 1.5 to 2 in (3.8 to 5.1 cm). Their skin has a lumpy texture to it, giving them a warty appearance. They are virtually indistinguishable from the Cope's Gray Tree Frog, Hyla chrysoscelis
, the only readily noticeable difference being their calls. Cope's Gray Tree Frog has a shorter, faster call. The Gray Treefrog also has an extra set of chromosomes (4N), or 48 in total, and is called Tetraploid Gray Treefrog in scientific circles. The more southerly Cope's Gray Treefrog, or Diploid Gray Treefrog, retained its 2N (24) original chromosome set, so hybridization between these species would not be successful.
Both Hyla chrysoscelis and Hyla versicolor have bright yellow patches on the hind legs, which distinguishes them from other treefrogs, such as Hyla avivoca. The bright patches are normally only visible while the frog is jumping. Both species of Gray Treefrogs are slightly sexually dimorphic
. Males have black or gray throats, while the throat of the female is lighter.
Tadpoles have a rounded body (as opposed to the more elongated bodies of stream species) with a high, wide tail that can be colored red if predators are in the system. Metamorphosis can occur in as little as 2 months with optimal conditions. At metamorphosis, the new froglets will almost always turn green for a day or two before changing to the more common gray. Young frogs will also sometimes maintain a light green color and turn gray or darker green after reaching adulthood.
. They also range into Canada in the provinces of Quebec
, Ontario
, and Manitoba
, with an isolated population in New Brunswick
.
The Gray Treefrog is capable of surviving temperatures as low as –8°C.
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 small arboreal frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
native to much of the eastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and southeastern Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
It is sometimes referred to as the Eastern Gray Treefrog, Common Gray Treefrog, or Tetraploid Gray Treefrog to distinguish it from its more southern genetically disparate cousin, the Cope's Gray Treefrog (Hyla chrysoscelis
Hyla chrysoscelis
The Cope's Grey Tree Frog 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...
). It may sometimes be referred to as the North American Tree Frog by Europeans to distinguish it from their European Tree Frog
European tree frog
The European tree frog is the common name of Hyla arborea. The original name of this frog was Rana arborea. Some of the other common names include:*Rainette verte *Laubfrosch *Ranita de San Antonio...
(Hyla arborea).
Physical description
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
themselves from gray to green, depending on the substrate they are sitting on. The degree of mottling varies. They can change from nearly black to nearly white. They change color at a slower rate than a chameleon
Chameleon
Chameleons are a distinctive and highly specialized clade of lizards. They are distinguished by their parrot-like zygodactylous feet, their separately mobile and stereoscopic eyes, their very long, highly modified, and rapidly extrudable tongues, their swaying gait, the possession by many of a...
. Dead Gray Treefrogs and ones in unnatural surroundings are predominantly gray.
They are relatively small compared to other North American frog species, typically attaining no more than 1.5 to 2 in (3.8 to 5.1 cm). Their skin has a lumpy texture to it, giving them a warty appearance. They are virtually indistinguishable from the Cope's Gray Tree Frog, Hyla chrysoscelis
Hyla chrysoscelis
The Cope's Grey Tree Frog 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...
, the only readily noticeable difference being their calls. Cope's Gray Tree Frog has a shorter, faster call. The Gray Treefrog also has an extra set of chromosomes (4N), or 48 in total, and is called Tetraploid Gray Treefrog in scientific circles. The more southerly Cope's Gray Treefrog, or Diploid Gray Treefrog, retained its 2N (24) original chromosome set, so hybridization between these species would not be successful.
Both Hyla chrysoscelis and Hyla versicolor have bright yellow patches on the hind legs, which distinguishes them from other treefrogs, such as Hyla avivoca. The bright patches are normally only visible while the frog is jumping. Both species of Gray Treefrogs 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, while the throat of the female is lighter.
Tadpoles have a rounded body (as opposed to the more elongated bodies of stream species) with a high, wide tail that can be colored red if predators are in the system. Metamorphosis can occur in as little as 2 months with optimal conditions. At metamorphosis, the new froglets will almost always turn green for a day or two before changing to the more common gray. Young frogs will also sometimes maintain a light green color and turn gray or darker green after reaching adulthood.
Gender identification
The female does not croak and has a white throat. The male does croak and has a black/gray throat. And, the female is usually larger than the male.Geographic range
Gray Treefrogs inhabit a wide range, and can be found in most of the eastern half of the United States, as far west as central TexasTexas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
. They also range into Canada in the provinces of Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
, Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, and Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
, with an isolated population in New Brunswick
New Brunswick
New Brunswick is one of Canada's three Maritime provinces and is the only province in the federation that is constitutionally bilingual . The provincial capital is Fredericton and Saint John is the most populous city. Greater Moncton is the largest Census Metropolitan Area...
.
The Gray Treefrog is capable of surviving temperatures as low as –8°C.
Habitat
The grey tree frog is most common in forested areas, as it is highly arboreal. Their calls are often heard in rural residential areas of the east coast.Behavior
These frogs rarely ever descend from high treetops except for breeding. They are strictly nocturnal. Male grey tree frogs rarely have large choruses as they are mostly solitary animals, but might vocalize competitively at the height of breeding periods.External links
- Gray Treefrog - Hyla versicolor Species account from the Iowa Reptile and Amphibian Field Guide
- Gray Treefrog - Hyla versicolor - audio recording of call
- Tetraploid Gray Treefrog (Hyla versicolor), Natural Resources Canada
- Northern gray tree frog New Jersey Pinelands flora,fauna,and landscapes photo galleries link to northern gray tree frog photograph