



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


September 9, 2006 - wwknapp@mindspring.com