Pig Frog
Rana grylio
Description:
- adult sizes range from 3-1/2 inches to 6-1/2 inches; it is the second
largest frog in Florida behind the Bullfrog
- Pig Frogs have narrow, pointed heads (the snout is narrower and more
pointed than that of a Bullfrog)
- the hind feet are fully webbed -- webbing on the longest toe extends
almost all the way to the tip (top photo); webbing on the longest
toe on other large frogs' rear feet stops well before the tip
- the eyes are noticeably elevated above the head and are fairly close
together
- colors can vary widely, but almost all have prominent, scattered dark
spots on the back
- the belly is whitish but may have dark spots, especially toward the
rear
- younger Pig Frogs are usually uniformly dark, but they can sometimes
be greenish
- adult Pig Frog colors
range from blackish-brown to an extremely dark olive green that blends
in with mud and tussocks, to bright green, to yellow
- genders can be distinguished by the tympanum (outer ear located just
behind the eye) -- that of the male is noticeably larger than the eye while
that of the female is the same size or smaller than the eye (right column--
male 3rd photo, female 4th photo)
- some males have bright yellow throats
- the thighs also have a light line or a row of light spots running across
their rear that other frogs of similar size don't have
Food:
- opportunistic feeders that will eat insects, worms, small amphibians,
small crustaceans like snails and crayfish, and small reptiles.
Call:
- regular call
- sounds like the guttural grunt of a pig
- a second call
sounds like the single plucking of a really large stretched and taut rubber
band
- alarm call is a single squeek
- Lang Elliott's NatureSound Studio (RealAudio)
Habitat:
- prefer permanent open waters of ponds, streams, lakes, rivers, swamps,
and marshes
- may either float in open water or choose a station on or amid floating/emergent
vegetation
- much more aquatic in nature than Bullfrogs
Range:
- entire state of Florida, and into southern and coastal South Carolina,
Georgia, Alabama, Mississippi, Louisiana, and extreme eastern coastal Texas
Breeding:
- breeding choruses call from April through the summer
- the choruses usually erupt at night when the vast majority of the mating
occurs
- rainy, overcast or humid overcast weather seems to provide conditions
that make for active mating
- they breed when the air is humid with temperatures ranging from 63-78
degrees.
- females lay more than 10,000 eggs as a surface film that may adhere
to surface or emergent vegetation
- eggs are small and bead-like and are laid in large masses on the surface
of the water
- hatching period is 2-3 days; eggs appear to have no animal predators;
their only threat is the receding water
- tadpoles in the northern part of the range take more than a year to
metamorphose while those in the southern Florida develop in considerably
less time
- tadpoles are quite large (100mm), with extremely long tails
- mature tadpoles are colorful with yellow bellies with prominent reticulation
on brownish black. Their sides have yellow spots that are encircled by
a pinkish color. From the throat region to the pectoral region is clear
black and across the pectoral region is green. The yellow spots surrounded
by pink continue down the tail in various patterns (Wright 1932)
- after transformation, young frogs remain in the same habitat as adults
Classification:
- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Vertebrata
- Class: Amphibia
- Order: Anura
- Family: Ranidae
- Genus: Rana (from Latin rana for frog)
- Species: grylio (from Greek gryllos for pig)
-
All photos ©2002-2003 Dick Brewer and taken in the
wild (which is where all frogs belong).
Sound ©2003 Ralph Arwood |
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