The Dendrobates leucomelas snout-to-vent length ranges from 31 to 38 mm (Walls 1994). D. leucomelas is the largest species of its genus and females are usually bigger and thicker than males (Honolulu Zoo 2002). Adult frogs are black dorsally with three broad crossbands colored bright yellow, yellow-orange, or orange; black spots or blotches are often present in the crossbands as well as on the yellow or orange limbs. The belly is black and usually lacks color. All markings are variable, making each frog unique. Color pattern does not seem to be correlated with geography. D. leucomelas lacks an omosternum and the tarsal tubercle is absent or barely present (Walls 1994). Unique glandular adhesive pads are present on the toes and fingertips, helping D. leucomelas to climb and stay in stationary positions. D. leucomelas also lacks webbing on its feet. Although adult D. leucomelas have been illustrated extensively, no illustrations of this species' tadpoles exist (USGS 2002).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Brazil, Colombia, Guyana, Venezuela
Dendrobates leucomelas is found in the Guianan Orinoco drainage of Venezuela north to the Río Orinoco, east into Guyana to the Essequibo River, south into extreme northern Brazil, and west into eastern Amazonian Colombia (Amphibian Species of the World AMNH website). They are native to South America but in 1994 one specimen was collected on Honolulu, Oahu, Hawaii, possibly due to a pet release (USGS 2002). D. leucomelas prefers moist or wet, forested, lowland regions and temperatures often reaching 30° C or warmer (Silverstone 1975; Honolulu Zoo 2002). They are usually found between 50 and 800 meters above sea level in leaf litter, fallen trees, forest floors, stones and occasionally trees (Honolulu Zoo 2002; Walls 1994).
Life History, Abundance, Activity, and Special Behaviors
Dendrobates leucomelas is an insectivore (mostly ants) and is diurnal (USGS 2002; Caldwell 1996; Silverstone 1975). D. leucomelas is toxic in its natural environment and derives its skin toxins from the ants in its diet (Caldwell 1996). It is the only poison frog known to estivate during the dry season (Walls 1994). Males will chirp, buzz, trill, and hum to get females attention while also showing off their brightly colored bodies for an hour or two after sunrise and before sunset (Honolulu Zoo 2002; Walls 1994). Once a female chooses a male she will follow him to his area and stroke his back and snout. Sometimes both the male and female will slowly circle one another and stamp their feet (Walls 1994). The D. leucomelas females compete for males, and the terrestrial eggs are guarded by the male parent in a moist, sheltered area (USGS 2002).
Females lay 100 to 1000 eggs per year and produce 2 to 12 eggs per clutch (Honolulu Zoo 2002). The male rotates the eggs every so often so that they receive enough oxygen. Unlike most historionicus-group dendrobatids, the D. leucomelas tadpoles do not rely on eggs for nutrition; but they will accept almost anything for food (Walls 1994). Once they hatch, the tadpoles are carried on the father's back to small pools of water where they continue to develop (USGS 2002; Richard Stockton College 2002). Metamorphosis takes 70 to 90 days; froglets resemble miniature adults but have duller colored bands. In captivity the froglets must eat regularly (fruit flies, pinhead crickets, and other small insects); going without food for 48 hours can lead to death. Some people have observed that they have a "sweet tooth" for small caterpillars (Walls 1994).
Trends and Threats
Since D. leucomelas is easily bred in captivity, the selling price on the international market has decreased (Barrio & Fuentes 1999). D. leucomelas is abundant in all places sampled by Barrio and Fuentes in the late 1990's. However, there has not been thorough monitoring to determine the current status of these frogs (Barrio & Fuentes 1998). Dendrobatids are exploited for the pet trade and it is believed that they are overharvested in some areas. They could face declines unless strict trade regulations are set. (CITES 2002). Their habitat is also being destroyed by timber industries and agriculture.
Relation to Humans
Humans keep D. leucomelas for pets and are popular species in the pet trade (USGS 2002). Some compounds of their skin have pharmacological properties, and have proved to be valuable in biomedical research (Honolulu Zoo 2002).
Possible reasons for amphibian decline
General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Intentional mortality (over-harvesting, pet trade or collecting)
Dendrobates auratus is an established exotic dendrobatid in Hawaii and most closely resembles D. leucomelas (USGS 2002). However, D. auratus does not have three distinct crossbands (McKeown 1996). Due to the absence of the omosternum, D. leucomelas is considered a close relative to D. historionicus (also lacking the omosternum). But Myers and colleagues have removed D. leucomelas from the historionicus-group due to its differences in call (Walls 1994). It has also been placed in the tinctorius-group because of its similarities to others in that group with tadpole behavior, aspects of color pattern, and its resemblance to D. auratus and D. tinctorius. It has also been successfully bred with D. tinctorius and D. truncates (Walls 1994).
American Museum of Natural History, Department of Herpetology (2002). Amphibian Species of the World Database. http://research.amnh.org/cgi-bin/herpetology/amphibia.
Barrio, C. L. and Fuentes, O. (1998). ''Distribución de Dendrobates leucomelas (Anura: Dendrobatidae) en Venezuela.'' Acta Biologica Venezuelica, 18(3), 35-41.
Barrio, C.L. and Fuentes, O. (1999). ''Sinopsis de la familia Dendrobatidae (Amphibia: Anura) de Venezuela.'' Acta Biologica Venezuelica, 19(3), 1-10.
CITES (2002). Cites Website. http://www.cites.org.
Caldwell, J. P. (1996). ''The evolution of myrmecophagy and its correlates in poison frogs (Family Dendrobatidae).'' Journal of Zoology (London), 240(1), 75-101.
Frank, N. and Ramus, E. (1995). A Complete Guide to Scientific and Common Names of Reptiles and Amphibians of the World. NG Publishing Inc., Pottsville, Pennsylvania.
Honolulu Zoo (2002). ''.'' ''http://www.honoluluzoo.org/yellow-banded_dart_frog.htm.''
McKeown, S. (1996). A Field Guide to Reptiles and Amphibians in the Hawaiian Islands. Diamond Head Publishing, Los Osos, California.
Myers, C. W. and Daly, J. W. (1976). ''Preliminary evaluation of skin toxins and vocalisations in taxonomic and evolutionary studies of poison-dart frogs (Dendrobatidae).'' Bulletin of the American Museum of Natural History, 157(3), 173-262.
Richard Stockton College of New Jersey Biology (2002). Information on the Breeding Cycle of Poison Dart Frogs. http://www2.stockton.edu/academics/undergraduate/natural_and_math_science/labs/biology/html/poison_frogs/info_breeding.html
Silverstone, P. A. (1975). ''A revision of the poison-arrow frogs of the genus Dendrobates Wagler.'' Natural History Museum of Los Angeles County, Scientific Bulletin, 21, 1-55.
USGS (2002). ''USGS NonIndigenous Aquatic Species .'' ''http://nas.er.usgs.gov.''
Walls, J. G. (1994). Jewels of the Rainforest: Poison Frogs of the Family Dendrobatidae. J.F.H. Publications, Neptune City, New Jersey.
Written by Phoebe Lehmann (plehmann AT oeb.harvard.edu), Harvard University
First submitted 2003-01-11
Edited by Meredith Mahoney and Phoebe Lehmann (2003-02-03)
Species Account Citation: AmphibiaWeb 2003 Dendrobates leucomelas: Yellow-headed Poison Frog <http://amphibiaweb.org/species/1638> University of California, Berkeley, CA, USA. Accessed Dec 11, 2016.
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Citation: AmphibiaWeb. 2016. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 11 Dec 2016.
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