Hyla gratiosa
barking treefrog

Barking treefrogs, Hyla gratiosa, are found from southern Virginia southward through Florida and into Louisiana. This species occurs mostly in the coastal plain, but its range extends up to the southern part of Tennessee with separate colonies in southeastern Kentucky (Conant and Collins, 1998; eNature.com and Inc, 2003). Barking treefrogs have also been introduced into the southern part of New Jersey (eNature.com and Inc, 2003). ()

Barking treefrogs reside both on land and in water. They are highly arboreal, and can be found in tree tops when the weather is warm. When the weather is dry, they dig themselves into the ground around tree roots and clusters of vegetation for moisture (eNature.com, 2003). During breeding season, groups of barking treefrogs come together at streams, ponds, and bayheads, and other permanent bodies of water (VDGIF, 2005). ()

Barking treefrogs are the largest treefrog species in the southeastern United States. They have a bulky or chubby form and have a length of 5.1 to 7 centimeters (eNature.com and Inc, 2003). The skin of these frogs has a very rough, granular appearance (eNature.com and Inc, 2003; VDGIF, 2005). Barking treefrogs have the capacity to change the color of their skin, therefore coloration varies greatly (Northern Prairie Wildlife Research Center, 2002). Color ranges from a bright lime-green, to various degrees of brown. However, these frogs almost always display darker spots on their backs (eNature.com and Inc, 2003; Northern Prairie Wildlife Research Center, 2002). A lighter stripe is present, which starts at the upper jaw and runs along the length of the body (eNature.com and Inc, 2003; VDGIF, 2005). A light green or yellow throat is present in males (eNature.com and Inc, 2003; Wright and Wright, 1995). To allow for climbing, barking treefrogs have rounded pads on the end of each digit (eNature.com and Inc, 2003; The University of Georgia, 2004). ()

Tadpoles take about one week to hatch from the eggs once they have been deposited ("Georgia Wildlife Web", 2000). A few days after hatching, the gills of the tadpoles begin to function, and they feed on algae (AWAKE, 2004). Tadpoles are quite large, with a length of up to 5 cm, and may take up to 1.5 to 2 months to metamorphose (U. S. Geological Survey, 2003). ()

Little is known about the lifespan of barking treefrogs in the wild, but in captivity they are fairly long-lived. An average of 7 years can be reached (Andrew Tillson Willis, 2005; Max-Planck-Gesellschaft, 2005). They have been known to live as long as 12.5 years in captivity (North Carolina Herpetological Society, 2005). ()

Hyla gratiosa is a solitary species. Being nocturnal, these frogs pass the day restfully, high up in a tree ("Georgia Wildlife Web", 2000). When the weather becomes hot and dry, barking treefrogs aestivate (AWAKE, 2004; "Georgia Wildlife Web", 2000). When the weather is cold, they hibernate (AWAKE, 2004). Both aestivation and hibernation are done under the cover of roots and other vegetation (AWAKE, 2004). Because of this occasional burrowing into the ground, barking treefrogs may be considered somewhat fossorial. ()

Home Range

The home range for these frogs is thought to be the forested areas that are right around their breeding ponds (VDGIF, 2005). When they are not breeding, they keep to this area. ()

Barking treefrogs use mostly vocal communication with conspecifics. When finding a mate, no visual cues are used (Duellman and Trueb, 1986). Barking treefrogs utilize two different calls in order to communicate (U. S. Geological Survey, 2003). The first call is a very loud note that they give when they are around water and ready to mate (eNature.com and Inc, 2003). This call is reiterated every 1 or 2 seconds (U. S. Geological Survey, 2003). The other call is given when these frogs are high in the trees (eNature.com and Inc, 2003; U. S. Geological Survey, 2003). This call resembles the bark of a dog, and is a call of 9 or 10 harsh syllables (U. S. Geological Survey, 2003).

In addition to vocal communiation, tactile communication may be important during amplexus.

Aside from vocal communication, barking treefrogs use visual cues in perceiving their environment. Their span of vision is very large, and they can easily detect movement in their environment (UF/IFAS, 1994). ()

Barking treefrogs are greedy, opportunistic feeders (The University of Georgia, 2004). They seach for food on the ground and in treetops, eating many arboreal insects (The University of Georgia, 2004; U. S. Geological Survey, 2003; VDGIF, 2005). Barking treefrogs very often end up feeding on crickets, Gryllus rubens (U. S. Geological Survey, 2003). ()

Barking treefrogs are predators on insects and in turn are prey to larger animals. The eggs and larvae of any frog are preyed upon by fish. The production of large numbers of eggs in one season may be a way of satiating aquatic predators while still having a smaller portion of offspring survive. Many birds look to frogs as an essential part of their diet (Babbitt and Tanner, 1994). These animals are also often eaten by snakes and raccoons (Congaree National Park, 2004).

One anti-predator adaptation of these frogs may be their sense of sight. The extent of their vision is quite large, and they can very easily detect movement (UF/IFAS, 1994). ()

As stated above, barking treefrogs are predators of many arboreal insects and prey to larger animals such as birds, snakes, and raccoons. This food web may be considered an ecosystem role. Hyla gratiosa also spends some time burying itself beneath vegetation on the ground (AWAKE, 2004; eNature.com and Inc, 2003; "Georgia Wildlife Web", 2000). This may serve as a way to aerate the soil. Beyond these relationships, little is known about their role in their environment. ()

There are no known adverse effects of H. gratiosa on humans.

Because barking treefrogs have a diet consisting mainly of insects, they can be quite helpful in regulating pest populations (AWAKE, 2004; The University of Georgia, 2004). Another benefit for humans is that barking treefrogs are used in the pet trade. They are great terrarium pets which will easily take insects from the owners' fingers (eNature.com and Inc, 2003). ()

Although barking treefrogs are listed as least concern by the IUCN Red List, they may still be adversely affected by human activities. Their populations have decreased in some places due to the expansion of buildings into habitats (U. S. Geological Survey, 2003). Because barking treefrogs utilize water for mating and reproduction, pollution into ponds and other bodies of water can be detrimental (AWAKE, 2004). Populations of these frogs can be maintained by preserving wetlands and pine woods (AWAKE, 2004; "Georgia Wildlife Web", 2000). ()