Hyla femoralisPine Woods Treefrog

Geographic Range

Pine woods treefrogs (Hyla femoralis) are native to the Neartic region, along the southeastern United States. The northernmost extent of their range is east-central Virginia. Their range extends as far southwest as the southern third of Mississippi and Alabama. Pine woods treefrogs are found between the Coastal Plain and the middle of the following states: Mississippi, Alabama, Georgia, South Carolina, North Carolina, and Virginia. Disjunct populations of pine woods treefrogs have been found in the city of Noxubee, Mississippi as well as Shelby and Tuscaloosa, Alabama. Pine woods treefrogs are also found throughout Florida. (Lannoo, 2005; Mitchell and Reay, 1999; Wilson, 1995)

Habitat

Pine woods treefrogs reside in temperate habitats, such as pine flatwoods and savannas. Pine woods treefrogs are regularly found in and around bogs, swamps, marshes, and pond cypress trees (Taxodium ascendens) in freshwater wetlands. Occasionally, pine woods treefrogs are found in hardwood forests near freshwater wetlands. Within wetlands, pine woods treefrogs reside in cabbage palms (Sabal palmetto) and pitcher plants (Sarracenia). In times of drought, they will leave dry areas in search of other wetlands. Within savanna habitats, pine woods treefrogs live on longleaf pines (Pinus palustris). In rural areas they breed along roadside ditches pooled with water. (Dorcas and Gibbons, 2008; Klaus and Noss, 2016; Lannoo, 2005; Martof, et al., 1989; Wilson, 1995)

  • Aquatic Biomes
  • lakes and ponds
  • temporary pools

Physical Description

Pine woods treefrogs have an average snout-vent length (SVL) of 40 mm, although females are slightly larger than males on average. They have symmetrical narrow bodies as well as legs that bend close to level with their eye. Pine woods treefrogs have light brown, dark brown, gray, or dull green skin; males and females do not differ in color or patterning. Pine woods treefrogs have irregular splotches of darker coloration along their dorsal sides. Their ventral sides are off-white, and the posterior portion of their thighs have yellow or orange spots of varying sizes. Individual pine woods treefrogs may vary in appearance depending on environmental temperature or stress. Pine woods treefrogs are ectothermic – their body temperature is regulated by their environment. Males have larger digits than females in order to grip females while mating. This behavior, known as amplexus, stimulates the release of eggs. Pine woods treefrogs have black eyes, with a moveable lower eyelid. They have the ability to retract their eyes in order to keep them lubricated.

Pine woods treefrog tadpoles are dark green or brown, with hints of orange along the body similar to the color of the thigh of adults. Like adults, tadpoles have splotches of darker color along their dorsal regions. The undersides of tadpoles are lighter variations of brown and green. Snout-vent lengths of tadpoles range from 11 to 15 mm. (Altig, 1972; Altig and McDiarmid, 2015; Dorcas and Gibbons, 2008; Hoffman, 1988; LaFiandra and Babbitt, 2004; Miller and Harley, 2016)

  • Sexual Dimorphism
  • female larger
  • sexes shaped differently
  • Average length
    40 mm
    1.57 in

Development

Pine woods treefrog eggs hatch about three days after being fertilized. Tadpoles grow to a length of 33 to 36 mm before they begin to metamorphose, which takes about 6 to 10 weeks. During metamorphosis their tail reduces in size, until it is fully absorbed. During metamorphosis they also develop jaws and limbs. Cells that develop during this process are similar to cells involved in embryonic development. Pine woods treefrogs grow indeterminately, which means they continue to grow throughout their life. (Altig, 1972; Altig and McDiarmid, 2015; Joachimczack, et al., 2005; LaFiandra and Babbitt, 2004; Lannoo, 2005; Travis, 1980)

Reproduction

Pine woods treefrogs use tactile and auditory communication during reproduction. Reproduction occurs during times of heavy rains but will also occur during droughts if there is remaining water in which females can lay eggs. Males use vocalizations to attract mates. While mating, males grasp the females around the waist to stimulate the release of eggs. This is known as amplexus. Eggs are fertilized externally, after females deposit their eggs in water sources. Female pine woods treefrogs have specific "release calls" to alert males that they are incapable of reproducing, done reproducing, or unwilling to reproduce. Pine woods treefrogs are polygynandrous, meaning both males and females have multiple mates throughout their life. (Altig and McDiarmid, 2015; Blair, 1958; Dorcas and Gibbons, 2008; Hoffman, 1988; Lannoo, 2005; Martof, et al., 1989)

Pine woods treefrogs reproduce sexually, fertilizing their eggs externally. They are iteroparous, meaning they mate multiple times throughout their life. Young develop from eggs laid by the mother, making this species oviparous. They breed seasonally, starting in March or April and ending in late August. Both males and females migrate from their non-breeding arboreal locations to areas closer to ponds, where mating occurs. Females lay eggs in clusters ranging anywhere between 200 and 2,000 eggs. Eggs are laid in groups of about 100, usually attached to vegetation 2 to 3 cm under the surface of the water. Tadpoles hatch from eggs after roughly 3 days. They are immediately independent upon hatching. Pine woods treefrogs are gonochoric, meaning they have two distinct sexes. Males and females both reach sexual maturity 2 to 3 years after metamorphosis. (Altig and McDiarmid, 2015; Blair, 1958; Dorcas and Gibbons, 2008; Hoffman, 1988; Lannoo, 2005; Martof, et al., 1989)

  • Breeding interval
    Pine woods treefrogs breed several times between March and August.
  • Breeding season
    Pine woods treefrogs have a breeding season beginning in March or April and ending in August. Females lay eggs from late spring to early summer.
  • Range number of offspring
    200 to 2000
  • Average number of offspring
    2000
  • Average time to hatching
    3 days
  • Average time to independence
    0 minutes
  • Range age at sexual or reproductive maturity (female)
    2 to 3 years
  • Range age at sexual or reproductive maturity (male)
    2 to 3 years

Both male and female pine woods treefrogs have no parental investment in offspring after eggs are laid. During external fertilization, females place fertilized ova near vegetation 2 to 3 cm below the surface of the water. This helps camouflage eggs before they hatch. (Altig and McDiarmid, 2015; Lannoo, 2005; Martof, et al., 1989)

  • Parental Investment
  • no parental involvement

Lifespan/Longevity

Pine woods treefrogs are not kept in captivity, so little is known about their lifespan. There is also not much information about their average lifespan in the wild. Other members of the genus Hyla, such as gray treefrogs (H. chrysoscelis) and (H. versicolor) have been observed to have a lifespan of 7.8 years in the wild. It is expected that pine woods treefrogs have a similar maximum lifespan. (Lannoo, 2005; Nigrelli, 1954; Snider and Bowler, 1992)

Behavior

Pine woods treefrogs are a solitary species, coming together in large groups only to breed. Breeding takes place around bodies of water, such as ponds. During the breeding season, males vocalize on vegetation (often trees), up to three meters above water sources. They sing in chorus during rainstorms, but are quiet during hurricanes.

When they are not breeding, pine woods treefrogs are arboreal. They occupy several different habitats throughout the year, and are considered the most terrestrial of the treefrogs in the southeastern United States. They are not known to defend any territory. Pine woods treefrogs are scansorial (adapted to climbing) and, when they are not breeding, they are found high up in trees.

They aestivate during warm periods, burying themselves in soil or under fallen bark and logs. They do not fully hibernate during the winter, instead emerging when days are warm enough to feed. On cooler winter days, these frogs bury up to 60 cm under the soil. Closer to the surface, they hide under decaying logs, cabbage palm Sabal palmetto, or bromeliads like Spanish moss Tillandsia usneoides.

Pine woods treefrogs are saltatorial, which means they are specialized for jumping and hopping. This helps them climb trees faster and catch prey. These frogs are crepuscular, meaning that they are most active at dusk and dawn. This is also the most likely time for breeding, which is why pine woods treefrogs are most often heard at night. (Dorcas and Gibbons, 2008; Hoffman, 1988; Lannoo, 2005; Wilson, 1995)

Home Range

Pine woods treefrogs are nomadic; they do not maintain a specific home range. They stay primarily in trees near breeding sites. They are not territorial and do not defend any specific region they occupy. (Dorcas and Gibbons, 2008; Hoffman, 1988; Wilson, 1995)

Communication and Perception

Pine woods treefrogs communicate primarily through vocal calls. This communication consists of short calls, or pips, back and forth between individuals. Hoffman (1988) refers to their vocal calls as having similarities to the short sounds of Morse code. Pine woods treefrog vocalization is primarily used by males to attract mates. However, females have specific calls to alert males that they are incapable of reproducing or done reproducing. Pine woods treefrogs communicate with several other species such as oak toads (Anaxyrus quercicus), little grass frogs (Pseudacris ocularis), and Fowler's toads (Anaxyrus fowleri). Communication between these species can also lead to hybridization. Males and females are both capable of producing distress calls to scare predators and alert other individuals of danger. These calls are louder and longer than mating calls. Pine woods treefrogs communicate through tactile means during reproduction. Males grasp females around their waists to stimulate the release of eggs. They also use olfaction when choosing specific mates. When hunting for food, they perceive their environment visually.

Pine woods treefrog tadpoles exhibit phenotypic plasticity. This means they perceive their environment through the production of metabolites by predators. When tadpoles detect predators some of their morphological features change, resulting in shorter bodies and tails overall. Smaller physiological features makes it easier for pine woods treefrogs to hide from predators. (Dorcas and Gibbons, 2008; Hoffman, 1988; LaFiandra and Babbitt, 2004; Lannoo, 2005; Miller and Harley, 2016)

Food Habits

Pine woods treefrogs are carnivorous, opportunistic feeders. Their prey include insects and other terrestrial arthropods including the following: caddisflies (Order Trichoptera), moths (Order Lepidoptera), craneflies (Order Diptera), jumping spiders (Family Salticidae), ants (Order Hymenoptera), grasshoppers (Order Orthoptera), and beetles (Order Coleoptera). Pine woods treefrogs that live in rural areas use artificial lights, which attract insects, to ambush their prey. (Dorcas and Gibbons, 2008; Lannoo, 2005; Wilson, 1995)

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods

Predation

Pine woods treefrogs have coloration that camouflages them in their environment. They also use an alarm call meant to surprise predators when they have been captured. This call is longer and louder than mating calls. According LaFiandra and Babbitt (2004), tadpoles that detect predators nearby likely develop shorter limbs and a shorter body overall after metamorphosis. Smaller average size keeps tadpoles from being seen and eaten.

Known predators of pine woods treefrogs include banded water snakes (Nerodia fasciata), black racers (Coluber constrictor), eastern ratsnake (Pantherophis alleghaniensis), common garter snakes (Thamnophis sirtalis), ribbon snakes (Thamnophis sauritus), and raccoons (Procyon lotor). (Barber and Babbitt, 2003; Dorcas and Gibbons, 2008; LaFiandra and Babbitt, 2004; Lannoo, 2005)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Pine woods treefrogs act as a host to species of nematode parasites, such as those in the genus Apelctana.

Pine woods treefrogs are indicative of wetland restoration success. Areas that have been successfully restored have a higher population of these frogs. Noise pollution that they produce leads to acoustic competition between species. Other frogs in their environment that vocalize to attract mates must compete with pine woods treefrogs to be heard. (Lymbery, et al., 2014; Mastistky, et al., 2010; Ortega, et al., 2015; Vilcinskas, 2015)

Commensal/Parasitic Species
  • Aplectana nematode species

Economic Importance for Humans: Positive

Pine woods treefrogs serve as a bioindicator of wetland restoration success. Areas that have been successfully restored will have a higher population of these treefrogs. (DeGregorio, et al., 2014; Dixon, et al., 2011; Lymbery, et al., 2014; Mastistky, et al., 2010; Ortega, et al., 2015; Tennessen, et al., 2016; Vilcinskas, 2015)

Economic Importance for Humans: Negative

Although pine woods treefrogs are considered a pest species due to noise pollution, there are no negative economic impacts associated with them. These frogs serve as hosts for parasites, such as nematodes in the genus Apelctana, which pose no threat to humans. (DeGregorio, et al., 2014; Dixon, et al., 2011; Lymbery, et al., 2014; Mastistky, et al., 2010; Ortega, et al., 2015; Tennessen, et al., 2016; Vilcinskas, 2015)

Conservation Status

According to the IUCN Red list, pine woods treefrogs are considered a species of least concern. Under the US Federal List, CITES, and State of Michigan list, they have no special status.

A major threat to pine woods treefrog populations is habitat alterations in rural and suburban areas. They reside mainly in rural areas, so new construction projects may reduce access to trees and breeding ponds that this species needs to survive.

According to Tennessen et al. (2016), pine woods treefrogs are considered to be a pest species in many areas. Their loud calls during breeding season contributes to overall noise pollution, which leads to anti-conservation measures. According to Lannoo (2005), there are other places, such as Florida, Louisiana, Mississippi, and Virginia, that have regulations specifically against selling pine woods treefrogs for profit. (Delis, et al., 1996; Lannoo, 2005; Tennessen, et al., 2016)

Contributors

Jessica Wyllie (author), Radford University, Lauren Burroughs (editor), Radford University, Logan Platt (editor), Radford University, Karen Powers (editor), Radford University, Galen Burrell (editor).

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

bog

a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

external fertilization

fertilization takes place outside the female's body

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

freshwater

mainly lives in water that is not salty.

indeterminate growth

Animals with indeterminate growth continue to grow throughout their lives.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

saltatorial

specialized for leaping or bounding locomotion; jumps or hops.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

References

Altig, R. 1972. Notes on the larvae and premetamorphic tadpoles of four Hyla and three Rana with notes on tadpole color patterns. Journal of the Elisha Mitchell Scientific Society, 88/3: 113-119.

Altig, R., R. McDiarmid. 2015. Handbook of Larval Amphibians of the United States and Canada. Ithaca, NY: Comstock Publishing Associates.

Barber, M., K. Babbitt. 2003. The relative impacts of native and introduced predatory fish on a temporary wetland tadpole assemblage. Oecologia, 136/2: 289-295.

Blair, F. 1958. Call structure and species groups in U.S. treefrogs (Hyla). The Southwestern Naturalist, 3/1: 77-89.

DeGregorio, B., J. Willson, M. Dorcas, W. Gibbons. 2014. Commercial value of amphibians produced from an isolated wetland. The American Midland Naturalist, 172/1: 200-204.

Delis, P., H. Mushinsky, E. McCoy. 1996. Decline of some west-central Florida anuran populations in response to habitat degradation. Biodiversity & Conservation, 5/12: 579–1595.

Dixon, A., W. Cox, E. Everham III, D. Ceilley. 2011. Anurans as biological indicators of restoration success in the greater Everglades ecosystem. Southeastern Naturalist, 10/4: 629-646.

Dorcas, M., W. Gibbons. 2008. Frogs & Toads of the Southeast. Athens, GA: University of Georgia Press.

Hoffman, R. 1988. Hyla Femoralis. Catalogue of American Amphibians and Reptiles, 436: 1-3.

Joachimczack, M., R. Suzuki, T. Arita. 2005. From tadpole to frog: Artificial metamorphosis as a method of evolving self-recognizing robots. Proceedings of the European Conference an Artificial Life: 51-58.

Klaus, J., R. Noss. 2016. Specialist and generalist amphibians respond to wetland restoration treatments. Journal of Wildlife Management, 80/6: 1106-1119.

LaFiandra, E., K. Babbitt. 2004. Predator induced phenotypic plasticity in the pinewoods tree frog, Hyla femoralis: Necessary cues and the cost of development. Oecologia, 138/3: 350-359.

Lannoo, M. 2005. Amphibian Declines. Oakland, CA: University of California Press.

Lymbery, A., M. Morine, H. Kanani, S. Beatty, D. Morgan. 2014. Co-invaders: The effects of alien parasites on native hosts. International Journal for Parasitology: Parasites and Wildlife, 3/2: 171-177.

Martof, B., W. Palmer, J. Bailey, J. Harrison III. 1989. Amphibians and Reptiles of the Carolinas and Virginia. Chapel Hill, NC: The University of North Carolina Press.

Mastistky, S., A. Karatayev, L. Burlakova, D. Molloy. 2010. Parasites of exotic species in invaded areas: Does lower diversity mean lower epizootic impact?. Diversity and Distributions, 16/5: 798-803.

Miller, S., J. Harley. 2016. Zoology. New York, NY: McGraw-Hill Education.

Mitchell, J., K. Reay. 1999. Atlas of Amphibians and Reptiles in Virginia. Richmond, VA: Virginia Department of Game and Inland Fisheries.

Nigrelli, R. 1954. Section of biology: Some longevity records of vertebrates. Transactions of The New York Academy of Sciences, 16/6: 296-299.

Ortega, N., W. Price, T. Campbell, J. Rohr. 2015. Acquired and introduced macroparasites of the invasive Cuban treefrog, Osteopilus septentrionalis. International Journal for Parasitology: Parasites and Wildlife, 4/3: 379-384.

Snider, A., J. Bowler. 1992. Longevity of Reptiles and Amphibians in North American Collections. Oxford, OH: Society for the Study of Amphibians and Reptiles.

Tennessen, J., S. Parks, T. Tennessen, T. Langklide. 2016. Raising a racket: Invasive species compete acoustically with native frogs. Animal Behavior, 114: 53-61.

Travis, J. 1980. Phenotypic variation and the outcome of interspecific competition in Hylid tadpoles. Evolution, 34/1: 40-50.

Vilcinskas, A. 2015. Pathogens as biological weapons of invasive species. PLoS Pathogens, 11/4: 1-5. Accessed November 24, 2019 at https://doi.org/10.1371/journal.ppat.1004714.

Wilson, L. 1995. Land Manager's Guide to the Amphibians and Reptiles of the South. Atlanta, GA: The Nature Conservancy.