Acris gryllus

Geographic Range

Acris gryllus lives in the temperate climate of the southeastern portion of the United States. The range of this species, also known as the southern cricket frog, extends from the southeastern corner of Virginia and spans through North and South Carolina, Georgia, Alabama, and Mississippi. A. gryllus has also been reported in the southwestern tip of Tennessee. All throughout these states, A. gryllus has been found in the areas with an elevation of 500-1000 m away from the coastline.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Although A. gryllus is a member of the tree frog family, it lives mostly on the ground or in freshwater areas with sunlight. Examples of prime habitat include shallow ponds with vegetation, meadows, creeks, marshes and coastal plain bogs. The southern cricket frog can also be found in roadside pools and ditches. In these areas, they can become quite abundant. Its main choices of habitation changes, however, when the southern cricket frog's range overlaps with that of Acris crepitans . When this occurs, A. gryllus will typically move to areas which have been drained of water. The population of A. gryllus becomes less active and enters a period of dormancy near the middle of December, and reanimates in mid-February.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial
• freshwater freshwater

• Terrestrial Biomes
• forest forest

• Aquatic Biomes
• lakes and ponds
• rivers and streams
• temporary pools

• Wetlands
• marsh marsh
• swamp swamp
• bog bog

• Other Habitat Features
• agricultural agricultural

Physical Description

This small frog can be found in several colors. Generally they range from black, brown, or reddish brown to bright green or gray. Along with these patterns of coloration is a stripe of contrasting color beginning anteriorly at the top of the snout and running along the back towards the posterior and ends at the urostyle. Between the eyes of A. gryllus , there is a triangle marking with two corners at each respective eye and the third corner connected to the stripe seen on the back. When compared to a similar species, the northen cricket frog , A. gryllus is found to be smaller and more slender. The snout is markedly more pointed, the legs are longer and more proportional to the size of the body, and there is less webbing between the toes. The first toe is partially free of webbing and 3 joints of the fourth toe are completely free. Warts appear on the skin, especially around the anal area, but are not as prominent as seen in the northern cricket frog. In addition to the stripe running down the back of A. gryllus , there is also a darker longitudinal stripe that can be seen on the rear of the thigh. There is slight sexual dimorphism seen with the southern cricket frogs. The females are generally the slightly larger sex with a length of 16-33 mm and the males achieve a length of 15-29 mm. The males have darker throats, whereas the females' throats are white. Males also have a single subgular sac. When young, the frogs are entirely aquatic tadpoles. Upon reaching adulthood, the recently changed frogs are roughly 14 mm.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger
• sexes colored or patterned differently
• male more colorful

Development

The eggs of the southern cricket frog are fertilized externally while in a freshwater habitat. The sperm enters the egg and soon a gelatinous cover envelopes the egg to protect it. It then develops into a gill-breathing larva, also known as a tadpole, which then metamorphoses into the mature, lung- breathing adult. From beginning to end, 90-100 days (on average) are needed to complete the metamorphosis.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

The process of mating starts with the male emitting a call to attract females. This also functions to let the other males of A. gryllus know to stay out of his territory. The female then chooses her mate who begins what is known as amplexing. This is a method of holding the female around her waist with his forelegs, which then stimulates hormones within the female. Because of this stimulation, the eggs are then released into the water and the male releases his sperm and thus fertilizes the eggs.

• Mating System
• polygynous polygynous

Although the male will call all year long, breeding is usually done in the months of February through October. Once the eggs are fertilized the female will lay the eggs either singly or in groups of 7-10. She will lay clumps of up to 150 eggs at one time and attach them to either to the vegetation beneath the water or along the bottom of shallow pond. Depending on the environmental factors, the eggs can hatch in four days. Then, within the 90-100 days it takes to complete metamorphosis, the tail disappears, the legs form, the mouth enlarges, and the lungs replace the gills.

• Key Reproductive Features
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • external external
• oviparous oviparous
• sperm-storing sperm-storing

No parental care is given.

• Parental Investment
• no parental involvement

Lifespan/Longevity

The average lifespan of frogs in the genus Acris is roughly four months. This is because many die as tadpoles. Those few that do survive to adulthood may live for a least a year.

Behavior

The southern cricket frog is a better jumper than the northern cricket frog with a long distance jump of 8 feet. This allows them to be able to escape from their predators. They also have the ability to orient themselves using the moon's movement and stellar patterns. A. gryllus is not a social animal by nature. However, mass congregations, identifiable by loud choruses of calls during breeding season, are very common.

• Key Behaviors
• terricolous
• saltatorial saltatorial
• natatorial natatorial
• diurnal diurnal
• motile motile
• sedentary sedentary
• hibernation hibernation
• solitary solitary
• territorial territorial

Communication and Perception

The call of A. gryllus sounds like a rapid "click-click-click", as if two small stones or marbles were being hit against each other. The rhythm of the call always remains the same- it never changes pitch or frequency. It is also a very fast constant chirp with one call per second. These calls can be heard in most weather and at any time of the day. A. gryllus males use this chirping for two main things: to attract females for mating purposes and to maintain inter-male spacing.

• Communication Channels
• acoustic acoustic

• Other Communication Modes
• choruses choruses

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• vibrations vibrations
• chemical chemical

Food Habits

A. gryllus is an insectivore, feeding on a wide variety of insects with a major part of their diet being mosquitoes. When in the tadpole stage, however, this species is a herbivore. As adults, to catch their prey, they sit and wait in ambush for insects. When a prey item comes near, they lunge forward and shoot out their tongue. The southern cricket frog has also been observed chasing after their prey on the ground.

• Primary Diet
• carnivore carnivore
  • insectivore insectivore
  • eats non-insect arthropods

• Animal Foods
• insects
• terrestrial non-insect arthropods

Predation

To protect itself from predators, the southern cricket frog is able to jump long distances of up to 8 feet and has the ability to camouflage itself either in the vegetation or water. The predators of A. gryllus are fish, large salamanders (such as Ambystoma tigrinum ), snakes (such as Thamnophis sirtalis ), turtles and wading birds.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

A. gryllus is an insectivore which consumes a variety of insects, some of which are harmful to crops. The southern cricket frog, in turn, is preyed upon by a plethora of different fish, salamanders, turtles, and snakes.

Economic Importance for Humans: Positive

The southern cricket frog consumes pest insects and some which may potentially harm crops.

• Positive Impacts
• controls pest population

Economic Importance for Humans: Negative

There are no known adverse affects of A. gryllus on humans.

Conservation Status

At present time, A. gryllus is not threatened.

Other Comments

N/A

Additional Links

AmphibiaWeb

Encyclopedia of Life

Contributors

David Armitage (editor), Animal Diversity Web.

Shanna Williams (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

References

Caldwell, J. 2002. "Disruptive Selection" (On-line). Accessed March 20, 2003 at http://www.uga.edu/srel/Reprint/0817.htm .

Knapp, W. 2002. "The Frogs and Toads of Georgia" (On-line). Accessed March 20, 2003 at http://wwknapp.home.mindspring.com/docs/southern.cricket.frog.html .

Martof, B., W. Palmer, J. Bailey, J. Harrison. 1980. Amphibians and Reptiles of the Carolinas and Virginia . Chapel Hill: The University of North Carolina Press.

Southwest Florida Amphibian Monitoring Network, 2006. "Amphibian Ecology" (On-line). FrogWatch.Net. Accessed March 20, 2003 at http://www.frogwatch.net/amphibian_ecology.htm .

University of Florida, 2002. "Frogs and Toads of Florida" (On-line). Accessed March 20, 2003 at http://edis.ifas.ufl.edu/BODY_UW089 .

Wright, A., A. Wright. 1949. Handbook of Frogs and Toads . Ithaca: Comstock Publishing Associates.

Zug, G., L. Vitt, J. Caldwell. 2001. Herpetology- An Introductory Biology of Amphibians and Reptiles . San Diego: Academic Press.