Wildlife Clinic

Species

Pig frog

Lithobates grylio

A big, bullfrog-like frog of southern swamps whose call sounds like grunting pigs.

A pig frog sitting among floating duckweed, olive-green with dark brown spots and a pointed snout.

Photo Anthony Batista (opens in a new tab) / iNaturalist, CC BY 4.0 (opens in a new tab)

At a glance

Size
About 8 to 14 cm long
Habitat
Marshes, swamps, lakes and ponds with floating plants
Diet
Crayfish, insects and small fish
In Georgia
The southern Coastal Plain, including the Okefenokee
Voice
Deep, piglike grunts
Rabies vector
No

Identification

Key marks
Large, green to olive with dark spots; pointed snout; webbing reaching the tip of the longest hind toe
Told apart from
American bullfrog, whose webbing does not reach the toe tip
Where to look
Among lily pads and floating vegetation

Behaviour

Pig frogs sit among floating plants and call with deep grunts on summer nights. They are almost entirely aquatic.

Why they matter

They are important predators and prey in southern swamps, eaten by alligators, herons and snakes.

Reproduction and lifecycle

Eggs — Thousands in a floating film
Hatching — In a few days
Tadpoles — Large; take up to a year or more to change
Maturity — In two years
Lifespan — Several years
Calling — On summer nights

Living around people

  • It is harmless and lives in open water.

Misconceptions

  • Grunting in a swamp is wild pigs. It is often pig frogs.

Related species

Seasonal activity

When this species is breeding, and when there are nests on the ground. Mowing during the shaded months is how most nests are found.

Breeding and active nests by month for this species
JanFebMarAprMayJunJulAugSepOctNovDec
BreedingJan: noFeb: noMar: noApr: noMay: noJun: noJul: noAug: noSep: noOct: noNov: noDec: no
Active nestsJan: noFeb: noMar: noApr: noMay: noJun: noJul: noAug: noSep: noOct: noNov: noDec: no
NotesUnder waterActive on warm daysActiveCallingBreedingBreedingBreedingYoung frogsActiveActiveActive on warm daysUnder water

Where it lives

Recorded in 6 states and provinces. Each one links to the other animals there, and to the rehabilitators licensed for them.

If you found one

Answer a few questions and you will get a specific answer for what you are looking at.

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