## 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

June 28, 2003 - wwknapp@mindspring.com