



Bird-voiced Treefrogs - Hyla avivoca

- Diagnostic Features:
- Size: 1 to 2 inches (25 to 51 mm)
- Color:
- General dorsal coloring gray, brown or green
- Other:
- Comparatively small treefrog
- Darker, blotchy patterning on back
- Discernible light spot under eyes
- Normally, a Warty dorsal surface
- Dark bars on hind limbs
- Pale yellowish green to greenish or yellowish white
on hidden surfaces of thighs
- Large toe pads present
- Similar Species:
- Gray
Treefrogs - larger size, concealed surfaces of the thigh and
groin are yellow to golden orange. There is a divided pustule at the
base of the fourth fingers on each hand (undivided in the Gray
Treefrogs). The call is a series of piping, bird-like whistles issued
in rapid succession (it is a musical trill in H. versicolor, and a
buzzing trill in H. chrysoscelis). The Bird-voiced Treefrog prefers
wooded swamps, where Gray Treefrogs are less likely to occur.
- A hybrid
between this species and Cope's Gray Treefrogs occurs in Georgia. Where
both call together, hybrid populations may reach 10% of the Cope's Gray
Treefrog populations. Call resembles H. versicolor. Color of groin
& inside leg is intermediate. See the Gray Treefrog listing for
more info.
- Sexual Dimorphism:
- Males average smaller than females
- Throats on males may be darkened during breeding
season
Natural History:
- Habitat:
- These frogs are found in brushy areas, often near
permanent rivers and creeks with side pools that are flooded in spring.
- Behavior:
- They are nocturnal and forage in the trees and shrubs.
They descend to the ground only to breed.
- Can be found crossing roads after or during rain.
- Breeding:
- Breeding occurs from April to July, depending on the
temperature and rainfall.
- Males generally call from heights of 1 - 2 meters above
the ground, usually on the stems or limbs of bushes or trees near the
edge of the water or overhanging the water.
- Preferred breeding sites are brush edged semi-permanent
to perminant pools. Will also call at the brush edged shores of larger
ponds.
- Female lays in shallow water, in packets of 6 to 15
eggs, total production about 650 eggs.
Voice: Sonogram
: Call
( Burke, Hancock, Talbot, & Crawford Counties )
- A ringing birdlike whistle, wit-wit-wit-wit rapidly
repeated 20 or more times.
- A single frog calling reminds one of whistling for a dog.
Tadpoles:
- Tadpole stage: 31 - 33 days
- Transformed size: 13 mm

- LTRF 2/3; narrow midventral gap in marginal papillae
absent; eyes lateral; P-3 medium to short, P-2/P-3 > 1.2
- body mostly black, dorsum of tail muscle with white, silver
or reddish bands that persist in preservative; similarly-colored band
extends between eyes and stripes extending from each eye to the
adjacent naris usually disappear in preservative; throat darkly
pigmented (based on melanic pigment; check with hand lens)
- The tadpole of the Bird-voiced Treefrog is distinctive.
When viewed from above, the eyes bulge wide on the sides of the head.
Tadpoles are black in color, with several copper to orange bands on the
top of the tail muscle, and an orange triangle on top of the head.
After metamorphosis, the juveniles are sometimes found in low shrubs
and vegetation around the margins of the swamps, or crossing nearby
roads after rain.
Range:
- In North America, these treefrogs are found from extreme
southern Illinois to Louisiana and east to the Florida panhandle,
east-central Georgia and adjacent South Carolina; isolated colonies in
Ga., Ala., La., and Okla.
- In Georgia, they are found primarily in the middle region
of the state. Distribution extends well above the fall line, mostly
along rivers.


- In Light Blue:
Williamson, Gerald K. & Moulis, Robert A., Distribution of
Amphibians and Reptiles in Georgia, Special Publication No. 3, Savannah
Science Museum, Inc. Savannah, Georgia, 1994
- In Green:
Sound Recordings
- In Yellow:
From Both '94 study and Sound Recordings
- In Magenta:
Photograph, not found by '94, may or may not be sound record
- In Medium Blue:
Photograph and in '94 study, may or may not be sound record
- In Orange:
County Record by other Herp Atlas Volunteers
- In Red:
US Distribution from various sources


May 25, 2008 - wwknapp@mindspring.com