Hyla ebraccataH._ebraccata-2.jpg

Common Name: Variegated Tree Frog, Hourglass Tree Frog, Harlequin Tree Frog

Class: Amphibia
Order: Anura
Family: Hylidae
Latin Name:
Hyla ebraccata

Range and Abundance:
H. ebraccata, a common small treefrog, is mainly found in Central America and northern South America lowland tropical regions, in and around swamps and ponds. This treefrog is found in the following parks:

  • Braulio Carrillo National Park
  • Carara National Park
  • Cahuita National park
  • Cano Negro National Wildlife Refuge
  • Corcovado National Park
  • La Selva Biological Reserve
  • Manuel Antonio Park
  • Tortuguero National Park
  • Robert & Catherine Wilson Botanical Garden

Coloration and Morphology: The common names of
H. ebraccata are predominantly derived from its characteristic identifications including colorations and specific markings. If the coloration a frog is referred to as variegated, then it has different colors and irregular splotches. H. ebraccata is mainly yellow to yellow-brown/orange and has dark brown splotchH._ebraccata-1.jpges (highly variated) – hence, variegated – although sometimes showing off an “hourglass”-shaped marking on the back – hence, hourglass. Tadpoles exhibit flashy gold and black coloration before turning into adult frogs.

Habitat:
H. ebraccata lives mainly in the trees of lowland topical forests and can be found at its breeding sites. The wet season signifies reproduction, so during this time, the tree frog can be found in and around ponds. At La Selva Biological Station, H. ebraccata can be found among the leaves of Spathiphyllum friedrichsthalii.

Ecology: Breeding can be extremely dangerous for
H. ebraccata – these tiny frogs must find a mate yet escape the clutches of hungry predators such as Cat-Eyed Snakes, Bulldog Fishing Bats, frog-eating spiders, and many other winged predators. The frogs have adapted behavioral techniques to increase efficiency of reproduction including an interesting relationship to Spathiphyllum friedrichsthalii. The female will lay her eggs on the underside of the leaves of the plants so that they are out of reach of aquatic predators and once the eggs hatch, the tadpoles can then slide off into the water.

Behavior: Research involving
H. ebraccata focuses predominantly on mating calls. During the breeding season, the males can be heard calling to the females from the vegetation. There are two types of calls: advertisement calls and aggressive calls. Advertisement calls consist of either single-note or multi-note calls. Both calls begin with a single buzzing introductory note, the pulsing of the aggressive calls at a higher rate than advertisement calls. When females approach, the male frogs give rapid single-note calls as a sign of courtship. Once within 30 cm, the female turns her flanks toward the male and he clasps her. Males compete for females and non-calling males may stay near calling males in hope of intercepting females. Isolated males, however, may give single-note advertisement calls. Multi-note calls are usually the same in aggressive and advertisement calls. Background noise interference is detected because the calls of H. ebraccata and H. microcephala are similar. This effects the behavior of the frogs because the males will reduce their call rates and multi-note calling when in the presence of other frogs that are calling. The frogs are very sensitive to noise and this may have to do with both their auditory system and their ability (or inability) to mask background noise.

Diet: No studies have been conducted, but this frog presumably eats arthropods.

Other species with which it interacts:
Spathiphyllum friedrichsthalii, Hyla microcephala, Hyla phlebodes

Personal Experience: On a night tour of the rain forest at La Selva, our group saw the Hyla on a branch of grass in the swamp area. We were able to recognize it because of its bright yellow color. These frogs were not visible during the day and if you want to get a closer look, you are probably going to have to put on your gear and go swimming in the swamp. Or get lucky.


References:

Miyamoto, Michael M. "Notes on the Reproductive Behavior of a Costa Rican Population of
Hyla ebraccata" Copeia (1980) 928-30.

Schwartz, Joshua J., and Kentwood D. Wells "The Influence of Background Noise on the Behavior of a Neotropical Treefrog, Hyla ebraccata" Herpetologica (1983): 121-9.

Schwartz, Joshua J., and Kentwood D. Wells "Interspecific acoustic interactions of the neotropical treefrog Hyla ebraccata" Behavioral Ecology and Sociobiology (1984): 211-24.

Wells, Kentwood D., and Kathleen M. Bard "Vocal Communication in a Neotropical Treefrog, Hyla ebraccata: Responses of Females to Advertisement and Agressive Calls" (1986): 200-10.

Wells, Kentwood D., and Joshua J. Schwartz "Vocal Communication in a Neotropical Treefrog, Hyla ebraccata: Aggressive Calls" (1984): 128-45.

Guyer, Craig, and Maureen A. Donnelly "Amphibians and Reptiles of La Selva, Costa Rica, and the Caribbean Slope: A Comprehensive Guide" University of California Press, Berkeley (2005) 52-53.