Barking Treefrog
Hyla gratiosa

Common Name:

Barking Treefrog

Scientific Name:

Hyla gratiosa

Etymology:

 

Genus:

Hyla is Greek and means "belonging to the woods".

Species:

gratiosa is derived from the Latin word gratiosus which means "favored or pleasing".

Average Length:

2 - 2.6 in. (5.1 - 6.7 cm)

Virginia Record Length:

Record length:

2.8 in. (7 cm)

Virginia Wildlife Action Plan Rating Tier II - Very High Conservation Need - Has a high risk of extinction or extirpation. Populations of these species are at very low levels, facing real threat(s), or occur within a very limited distribution. Immediate management is needed for stabilization and recovery.

PHYSICAL DESCRIPTION: This species is the largest hylid frog in North America *10989*. Adults of this species range in size from 51-69 mm (2-2.75 in.) *11407* *1014* *10989*. It is one of the more robust treefrog species *1014* *11407*. Sexual dimorphism is not evident *10989*. Dorsal coloration ranges from a pale green-gray to bright green to dark brown *1014*. Profuse, circular dark markings are usually present on the dorsum though they are variable and may change with background color changes *1014* *11407*. The ventrum is typically white or yellowish white *1014*. Arms are thick and muscular. There is a distinctive fold of skin on the wrists. Hands and feet are large with wide toe tips and extensive webbing *9286*. Mature tadpoles reach lengths of 34-50mm. Tadpoles can be distinguished by the following physical characteristics: very high dorsal fin, dark saddles, and a long, tapering tail tipped with a flagellum *9286*.

REPRODUCTION: In Virginia, breeding has been observed in June and July *10989*. Breeding has been observed in shallow ponds only after heavy summer rains *1014* *10989*. Males migrate to the breeding sites to establish calling territories before the females arrive *10989*. As the males approach the breeding area they call from treetops *11407* *1014*. This call is a characteristic barking call of nine or ten raucous syllables from which they acquired their common name. The breeding call given while floating on the surface is a single, loud "doonk" or "toonk" repeated every one or two seconds *11407* *1014*. Females arrive soon after the males and engage in amplexus *10989*. The entire clutch is shed into the water. The eggs then break apart and develop singly on the substrate. Clutch size ranges from 1833-2881 (Virginia specimens) with an average of 2000 eggs (general description) *1014* *10989*. Eggs are laid in water of about 0.5 m depth *11284*. Most females breed once per season however multiple clutches are not unknown *11406*. Eggs hatch in several days, actual length of development is dependent upon temperature. Tadpoles generally metamorphose between July and September *10989*. The larval period typically lasts between 40 and 70 days; newly transformed young are 14-20mm long *1014*. The length of the larval period is dependent upon many factors including water temperature, the timing of drying of the pond, food availability, and population density *10989* *11406*. It has also been shown that the duration of the larval period is inversely related to early larval growth rates *11406*.

BEHAVIOR: This species spends most of its life in arboreal retreats in forested habitats *10989*. It is both a burrower and a high climber using arboreal habitats during favorable, warm, wet conditions *11407* *9286*. In general, this species has been found in sandy areas near shallow pools in pine savannas and in lowland woods and swamps *1014*. In Virginia, they have been observed in the following habitats: temporary pools in powerline right-of-ways, forested wetland depressions, natural Carolina bays and sinkhole or cypress ponds *10989*. In unfavorable, hot, dry weather, this species takes shelter in sand or soil beneath roots or clumps of grass or other vegetation *11407*. Individuals become most active in late spring and summer particularly following heavy rains *11407* *10989*. This is when migration to breeding ponds occurs. It is believed that individuals may use more than one pond over the course of the breeding period or that they may migrate large distances during ideal conditions to reach a specific breeding pond. Males establish calling territories at these ponds prior to the arrival of the females *10989*. Males call from the trees as they are approaching the breeding ponds and then from the pond margin or while floating on the water surface *11407* *10989*. The primary food of the adults of this species are insects and other invertebrates; tadpoles feed by scraping algae and other microorganisms from all available surfaces *10989*. This species is an opportunistic feeder *11284*.

ORIGIN: Native

LIMITING FACTORS: The primary limiting factor for this species is the number of breeding ponds *10989*. This species requires deeper and more permanent ponds than those required by other treefrog species. These ponds most still be free of predaceous fish *11284*. These ponds and the surrounding forests are being drained and otherwise altered for agriculture, forestry, and urban development *10989* *9286*.

POPULATION PARAMETERS: Survival rates of larvae are extremely variable and probably follow a Type III or hyperbolic survivorship curve typified by high mortality in the early stages of growth. The probability of surviving to metamorphosis is most likely highly variable. Adult survival rates though unknown are thought to be much higher than those of the larvae *10989*.

AQUATIC/TERRESTRIAL ASSOCIATIONS: This species is found generally in sandy areas near shallow ponds in pine savannas and in lowland forest wetlands and swamps *1014*. It is typically associated with willow oak-black gum hardwoods and pine savannas or flatwoods *11284*. More specifically in Virginia, these frogs are found in temporary pools in powerline rights-of-way, water-filled depressions in forested wetlands, natural Carolina bays, and sinkhole and cypress ponds *10989*. Breeding occurs in shallow ponds following seasonal heavy rains *1014*. In Virginia, this species is known to breed in temporary ponds dominated by graminoids *9286*. This species takes shelter in arboreal retreats or in burrows beneath roots or clumps of grass or other vegetation *11407*.

References for Life History

  • 1014 - Martof, B.S., Palmer, W.M., Bailey, J.R., Harrison, III J.R., 1980, Amphibians and Reptiles of the Carolinas and Virginia, 264 pgs., UNC Press, Chapel Hill, NC
  • 9286 - Terwilliger, K.T., 1991, Virginia's endangered species: Proceedings of a symposium. Coordinated by the Virginia Dept. of Game and Inland Fisheries, Nongame and Endangered Species Program, 672 pp. pgs., McDonald and Woodward Publ. Comp., Blacksburg, VA
  • 10989 - Virginia Department of Game and, Inland Fisheries, 1994, Hyla gratiosa, Barking Treefrog, Recovery Plan Non-game and Endangered Species Program, 26 pgs., Virginia Dept. of Game and Inland Fisheries, Richmond, VA
  • 11284 - Wilson, L.A., 1995, Land manager's guide to the amphibians and reptiles of the South, 360 pp. pgs., The Nature Conservancy, Southeastern Region, Chapel Hill, NC
  • 11406 - Duellman, William E. and, Trueb, Linda, 1986, Biology of Amphibians, 671 pgs., The Johns Hopkins University Press, Baltimore
  • 11407 - Conant, Roger and, Collins, John T., 1998, Peterson Field Guide: Reptiles and Amphibians, Eastern/Central North America, 616 pgs., Houghton Mifflin Company;, Boston

Photos:

*Click on a thumbnail for a larger version.


Verified County/City Occurrence

Brunswick County
Chesterfield County
Greensville County
Isle of Wight County
Lunenburg County
Mathews County
Nottoway County
Prince George County
Southampton County
Surry County
Sussex County
Virginia Beach City
Verified in 12 Counties/Cities.



FROGS

Virginia is home to 28 species of frogs and toads.

SALAMANDERS

We have a large diversity of salamanders consisting of 56 different species and subspecies.

LIZARDS

Virginia is home to 9 native lizard species and two introduced species, the Mediterranean Gecko and the Italian Wall Lizard.

SNAKES

The Commonwealth is home to 34 species and subspecies of snake. Only 3 species are venomous.

TURTLES

Virginia has 25 species and subspecies of turtle. Five of these species are sea turtle.