As juveniles, southern chorus frogs inhabit wet meadows and forested wetlands. Froglets tend to stay near their natal ponds for several weeks. As southern chorus frogs mature, they move away from the wetlands and meadows and towards pine (Pinus) forests. Adult southern chorus frogs can also be found near limestone sinkholes, especially bordering wet prairies in southern parts of Florida. They can also be found where the soil is sandy in Alabama.
Southern chorus frogs breed in wet seasons in otherwise xeric habitats. During the breeding season, they inhabit a wide variety of waterbodies, including ponds, bogs, marshes, and, rarely, floodplains. They also use temporary waterbodies like open-canopied vernal pools, roadside ditches, woodland ponds, Carolina bays, and flooded fields. Additional habitats include weedy margins of shallow flatwoods ponds and flooded pine-hardwood ditches.
Adult southern chorus frogs' skin is brown, gray, or tan. These frogs have three distinguishable, longitudinal stripes or linear rows of spots on their dorsum. There is also a white line that runs along their pointy snout and upper lip, and they have dark bands along their eyes. Male chorus frogs have an olive color or a rusty orange throat; females’ throats are lighter. The skin of these frogs is mainly smooth except for some granular bumps on their dorsum. Male and female southern chorus frogs differ slightly in size; males range in SVL from 21 mm to 30 mm and females are slightly larger, 22 mm to 33 mm SVL.
As tadpoles, they possess a light stripe that begins at the eye and continues to their tail. They have brown tails on the dorsal side, often with black spotting, but tails are lighter on the ventral side. Bodies are darker, either brown or black, and they have yellow or spotting throughout the dorsum. Like the tail, the ventral side of the body is lighter in color. At hatching, southern chorus frogs' total length averages 4.5 mm. They continue to grow as tadpoles until they reach a total length of 35 mm. Post-metamorphosis, young frogs have a SVL that ranges from 8.5 mm to 15 mm. (Dorcas and Gibbons, 2008; Gates, 1988; Lannoo, 2005; Wilson, 1995)
Southern chorus frogs go through metamorphosis. After 30-90 days after hatching, the tadpole stage ends, and metamorphosis begins. The length at hatching for the southern chorus frog is approximately 4.5 mm long. After 1-4 months, the tadpoles metamorphose into juvenile froglets. After the tadpoles undergo this process, they can grow between 9-15 mm in length in the juvenile stage. The froglets remain near the shallow water in which they hatched for several weeks. After approximately a year (range: 8-14 months), the froglets reach sexual maturity. The males can range from 21-30 mm in length, and the females can range from 22-33 mm in length. Like all frogs, their growth is indeterminate. (Caldwell, 1987; Dodd Jr, 2013; Ethier, et al., 2021; Lannoo, 2005; Wright and Wright, 1949)
Southern chorus frogs can be described as polygynandrous, males and females mate with multiple pairings. Like their name suggests, male southern chorus frogs call in large choruses in temporary or shallow permanent waterbodies. Males call to attract female southern chorus frogs, and choruses are more pronounced immediately after heavy rains. Calling allows the female chorus frogs to determine the quality of a potential mate, while it allows the male chorus frogs to determine the quality of their competitors. Males call, but choose call sites that are heavily vegetated to avoid predation. (Dodd Jr, 2013; Ethier, et al., 2021; Lannoo, 2005)
The breeding season for southern chorus frogs varies greatly by geographic location. For example, in Florida, the season is the longest, lasting 9 months from January until September; however, most breeding here occurs mid-summer. In Alabama and South Carolina, these frogs breed December through May, and are considered winter breeders.
Males and females breed via amplexus, using external fertilization. Female chorus frogs lay up to 160 eggs, in clusters of 15 up to 150. However, total reproductive efforts are estimated at 500-1500 eggs per season. The females place the eggs in clusters near vegetation of shallow water. The eggs typically hatch within a week of being laid; Lannoo (2005) reported that in Florida, they hatched in 2.5 days. Tadpoles are independent at hatching.
Tadpoles are in the larval stage for 28-90 days before metamorphosis commences. Froglets also take a few months to develop into adult frogs. Egg and tadpole development is affected by factors such as water temperature, predation levels, and other environmental conditions. Caldwell (1987) studied these chorus frogs in South Carolina, and found that sexual maturity was reach between the ages of 11.5 to 14 months for both sexes. Dodd, Jr. (2013) suggests that maturity is reached in 8 to 10 months. (Caldwell, 1987; Dodd Jr, 2013; Dorcas and Gibbons, 2008; Ethier, et al., 2021; Lannoo, 2005; Wilson, 1995)
There is no parental investment reported for southern chorus frogs beyond the act of mating. (Dodd Jr, 2013)
The longest recorded lifespan for southern chorus frogs was three years. The typical lifespan for these frogs is one year.
Breeding sites influence the longevity of adult southern chorus frogs, with survival rates ranging from 15% to 34% for males and 27% to 55% for females in Caldwell's (1987) study in South Carolina. Generally, congregating in large numbers at breeding sites increases the risk of predation. Dodd Jr. (2013) reported that less than 3.2% of adults reproduce in 2 consecutive years (suggesting high mortality).
Southern chorus frogs are saltatorial (which means they are specialized for jumping and hopping), nocturnal, and social (which means they live mainly in a group) - but only when breeding.
Like many other frog species, southern chorus frogs concentrate activity at night, but male frogs in chorus may begin to call during the daytime, around dusk. They are also a migratory species because they move in between the wetlands and other shallow waters during the breeding season to upland pine (Pinus) forests for the remainder of the year. Southern chorus frogs are also a social, polygynandrous species.
These chorus frogs are active during the winter, even beginning the breeding season in December or January in some parts of their range. Male chorus frogs call to find mates, but call mainly while hidden in thick vegetation or nearly underwater. They form large choruses and are especially active after heavy rainfall events. Depending on the year (influenced by rainfall and temperature), both sexes stay at a breeding pond from 1 to 61 days. When they leave breeding areas, most movement occurs nocturnally (likely to avoid visual predators). (Dodd Jr, 2013; Dorcas and Gibbons, 2008; Ethier, et al., 2021)
Home range and territory size has not been reported for southern chorus frogs. In non-breeding periods, they are not known to defend an area. During heavy breeding times, males may occupy a small area in the pool but aggressive encounters have not been reported. (Caldwell, 1987; Dodd Jr, 2013)
Southern chorus frogs communicate by an advertisement call. Males’ advertisement calls can be described as a slow trill (called "ik-ik-ik" by Dodd, Jr.) which on average have 6-12 pulses per second, with 1 to several seconds of break between trills. The pneumonics of the call are reported by Dodd, Jr (2013) as 3.325 kHz lasting, on average 0.39 seconds.
In most locations, except Florida, the months of December through April are when the chorus frogs are actively calling to mate, even in crepuscular hours. Male chorus frogs call to mate while remaining hidden in thick grasses or nearly underwater. Female southern chorus frogs are able to accurately discern calls between their own species and other sympatric frogs that belong to the same genus, such as spotted chorus frogs (Pseudacris clarkia). This stands true even when confronting varying environmental conditions, such as changes in ambient air and water temperatures, which affect the duration and trill rates of calls.
These frogs mate via amplexus, so they use visual and tactile senses to communicate. Color differences between sexes also suggest a reliance in visual mate recognition. (Dodd Jr, 2013; Dorcas and Gibbons, 2008; Michaud, 1964; Wright and Wright, 1949)
Food habits of southern chorus frogs are not well-studied, limited to two studies that address the issue. Dodd, Jr. (2013) suggests they are opportunistic insectivores. Duellman and Schwartz (1958) examined 10 stomachs in southern Florida and reported finding ants (Order Hymenoptera, family Formicidae) and beetles (Order Coleoptera). Another anecdotal report says the adults consume grasshoppers (Order Orthoptera). In their tadpole phase, they mainly feed on algae. (Dodd Jr, 2013; Dorcas and Gibbons, 2008; Duellman and Schwartz, 1958; Lannoo, 2005; Wilson, 1995)
Southern chorus frogs are eaten by species of birds (especially owls) and snakes. Tadpoles fall prey to predacious aquatic insects, and tiger salamander (Ambystoma tigrinum) larvae. To avoid daytime, visual predators, adult southern chorus frogs concentrate breeding activity at night. Further, these frogs may hide in tall grasses to avoid risk of detection.
Southern chorus frogs’ survival rates range from 15% to 34% for males and 27% to 55% for females in Caldwell's (1987) study in South Carolina. Much of the mortality is a direct result of predation. (Caldwell, 1987; Dorcas and Gibbons, 2008; Lannoo, 2005)
Southern chorus frogs fit into the food web as predators and as prey. They consume algae as tadpoles and insects as adults. As prey, in the tadpole stage they are eaten by salamander larvae and aquatic insects. As adults, they are eaten by species of birds, owls, snakes, and aquatic insects.
Trematodes (Glypthelmins pennsylvaniensis) have been found parasitizing southern chorus frogs. There were oral deformities found in the southern chorus frogs in South Carolina, which are often a sign of trematode parasites. (Burger and Snodgrass, 2000; Dodd Jr, 2013; Dorcas and Gibbons, 2008; Lannoo, 2005)
The economic impact of southern chorus frogs is minimal, as their commercial value is set at $0.50. (Witczak and Dorcas, 2009)
There are no negative economic impacts of southern chorus frogs on humans.
Southern chorus frogs are listed as species of “Least Concern” on the IUCN Red List. They also have no special status for the US federal list, CITES, and State of Michigan lists.
A major threat to southern chorus frogs is habitat loss. As a species that relies on pine (Pinus) forests and wetlands across their range, loss of both habitats for urban and commercial development has the potential to cause significant harm. For example, compared to historical land coverage, longleaf pine (Pinus palustris) forests have declined by more than 99%. The conversion of these lands to commercial pine plantations, suppression of fire on which longleaf pines depend, and changing of wetland placement on the landscape all pose threats to these frogs. Development of roads and railroads also make it more difficult for southern chorus frogs to reach a suitable habitat.
Southern chorus frogs lack federal- and state-specific protections. Although there are no active conservation measures in place, protection of mature forests and wetlands would benefit this and other species. (IUCN SSC Amphibian Specialist Group, 2014; Lannoo, 2005)
Ashley Welch (author), Radford University, Karen Powers (editor), Radford University, Victoria Raulerson (editor), Radford University, Christopher Wozniak (editor), Radford University, Genevieve Barnett (editor), Colorado State University.
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.
uses sound to communicate
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.
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.
an animal that mainly eats meat
uses smells or other chemicals to communicate
to jointly display, usually with sounds, at the same time as two or more other individuals of the same or different species
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
fertilization takes place outside the female's body
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
mainly lives in water that is not salty.
An animal that eats mainly plants or parts of plants.
Animals with indeterminate growth continue to grow throughout their lives.
An animal that eats mainly insects or spiders.
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).
marshes are wetland areas often dominated by grasses and reeds.
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.
makes seasonal movements between breeding and wintering grounds
having the capacity to move from one place to another.
specialized for swimming
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
specialized for leaping or bounding locomotion; jumps or hops.
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
uses touch to communicate
Living on the ground.
uses sight to communicate
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