Dendrobates leucomelas

Geographic Range

Yellow banded poison dart frogs, Dendrobates leucomelas , are found in the Neotropical region, in northern South America. The range includes Venezuela, northern Brazil, Guyana and southeastern Colombia.

• Biogeographic Regions
• neotropical neotropical
  • native native

Habitat

Yellow-banded poison dart frogs prefer humid or wet habitats and can be found on forest soil in moist stones, wet tree trunks, and roots of rainforest trees. Tadpoles can be found in epiphyllic plants such as bromeliads. They are found in lowland regions with average temperatures of 26 to 30 degrees celsius or above. These frogs have been reported at elevations of 50 to 800 m above sea level.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• rainforest rainforest

Physical Description

Dendrotes leucomelas is one of the largest species in the genus Dendrobates , with an adult body (snout to vent) length ranging from 3.1 to 5 cm, although individuals are only rarely more than 4 cm. Average weights of 3 g are reported.

This species is defined by its distinctive yellow and black bands across the body. As an individual frog ages, the black bands often break off into spots. This bright coloration undoubtedly represents aposematic coloration, which is defined as having conspicuously bright colors that are used as a warning of danger or distastefulness to potential predators. These frogs are known to produce toxic chemicals in their skin, making htem poisonous to most would-be predators. Females of this species are often larger and more robust than the males.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry
• poisonous poisonous

• Sexual Dimorphism
• female larger

Development

Male poison dart frogs find the best site for the female to deposit a few large eggs, usually on the underside of a leaf that is near water. The eggs are then fertilized, protected and maintained by the male. It is the male's duty to keep the eggs moist so they can grow. There are conflicting reports of the paternal care of these frogs, with some accounts indicating that the male of this species transports the fertilized eggs in his mouth to water (Honolulu Zoo, 2003) and others indicating that the male transports tadpoles to water after the eggs have hatched (Lehmann, 2003). The reason for this discrepency is not apparent, although it may be reasonably concluded that transport of the young is accomplished by their father. Eggs hatch into tadpoles about 10 to 14 days after fertilization.

After 70 to 90 days, the tadpoles have fully metamorphed into froglets. They are mature between 12 and 18 months.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

During mating season, males use vocalizations described as chirps, buzzes, trills, and hums to get the attemtion of females. They also show off their brightly colored bodies. Calling is most intense for an hour or two after sunrise and before sunset.

After a female chooses a male, she follows him to his chosen breeding ground and strokes his back and snout. Sometimes both the male and female slowly circle one another and stamp their feet. Females compete for males.

The male frog leads the female to an appropriate spot to deposit her eggs. The eggs are usually laid on leaves, in areas of high humidity. Then the male frog tends to the eggs and newly hatched tadpoles.

In some species in the genus Dendrobates , newly hatched tadpoles cling the male's back. Sitting upon their father, the tadpoles ride through the forest understory. The male climbs high up into the forest canopy, where he deposits the tadpoles into one of a variety of water-holding plants, particularly bromeliads. Although most sources indicate that this is also true for D. leucomelas , at least one indicates that the male transports the eggs to a water source prior to hatching (Honolulu Zoo, 2003).

Bromeliads are ideal for tadpole growth because they have numerous cup-like leaves filled with water. One tadpole is placed in each pocket of water. The parent distributes the tadpoles among many plants, presumably so that predators will not be able to locate all of the tadpoles. The primary predators on the tadpoles are giant damselfly nymphs, which have hatched from eggs also laid in the bromelid plants.

Another danger for the tadpoles is other dart frogs, including conspecifics. If an adult frog approaches a plant that is already occupied, the tadpole will produce a warning signal by aiming its head at the center of the plant, holding itself rigid, and rapidly vibrating its tail. If an tadpole-carrying parent ignores this signal and accidentally deposits another tadpole in the same bromelid sanctuary, the original tadpole will eat it.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Breeding occurs during a limited season each year, from February to March. Female D. leucomelas lay multiple clutches of 2 to 12 eggs, and may lay as many as 1000 eggs during the breeding season.

Eggs are fertilized externally, then cared for by the male of the species. Young metamorphose by 70 to 90 days of age. The young froglets are sexually mature by two years of age.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • external external
• oviparous oviparous

The degree and pattern of parental care varies between species of poison dart frogs. In D. leucomelas , the male does all of the parenting. The male tends to the eggs and the hatched tadpoles, and transfers them to the water-filled cavities high in the forest canopy. The female provides the eggs with nutrients to support the tadpole before it hatches, but the male continues to wet and protect the young until they are independent.

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • male
  • protecting
    • male
• pre-weaning/fledging
  • protecting
    • male

Lifespan/Longevity

The longest living Dendrobates in captivity survived for 20.5 years. However, the expected lifespan of a poison dart frog in captivity is 10 to 15 years. In the wild, individuals probably live from 5 to 7 years.

Behavior

Dendrobates leucomelas is diurnal. Frogs live mainly on the ground, but also climb into trees. These frogs have glandular adhesive pads on their toes and fingertips, which help them to adhere to plant surfaces. This allows these frogs to climb and cling.

Male D. leucomelas are very territorial and can be aggressive in defense of a calling/breeding territory. Males call from their oviposition sites to attract females. Other frog species are ignored or avoided. Territorial disputes can lead to aggressive behavior that can include grasping belly-to-belly and emitting a sporadic buzzing call. When not breeding, these animals are a solitary. The size of the territory is unknown.

• Key Behaviors
• scansorial
• terricolous
• saltatorial saltatorial
• diurnal diurnal
• motile motile
• sedentary sedentary
• solitary solitary
• territorial territorial

Communication and Perception

Males use vocalizations such as chirps, buzzes, trills and hums to attract females. Direct behavioral actions facilitate courtship and stimulate oviposition. Call sound like pleasant "birdlike" trills, lasting for 10 to 15 seconds.

In addition to vocalizations, males use visual cues as well to show off their brightly colored bodies. Tactile communication is important in breeding, as females and males touch one another in courtship.

Tadpoles use vibrations through water to signal their presence in a water pool to adult frogs. Should a male deposit a second tadpole into a pool, the first tadpole is likely to eat it.

These frogs depend upon vision to locate prey. In general frogs are not known to have a strong sense of smell, so it is unlikely that they use chemical communication.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic

• Other Communication Modes
• vibrations vibrations

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• vibrations vibrations

Food Habits

Largely insectivorous, the diet of these frogs consists of ants, termites, tiny beetles, crickets, and other small insects and spiders. They spend most of their time in the wild foraging for food, presumably because their prey are so small. In captivity, they are fed crickets and fruit flies (often, "pinhead" crickets and wingless fruit flies). When raised in captivity, D. leucomelas lose their skin toxins, which indicates that they may synthesize the toxins from some component of their diet. One major source of food in the wild that may provide chemicals to synthesize the toxins are formacine ants.

Young are sometimes canabalistic, although this behavior is apparently limited to times when unwary adults place new tadpoles into an already occupied pool. Although some Dendrobates species feed their young with unfertilized eggs, this behavior has not been observed in D. leucomelas .

• Primary Diet
• carnivore carnivore
  • insectivore insectivore

• Animal Foods
• amphibians
• insects
• terrestrial non-insect arthropods

Predation

Many potential predators are undoubtedly repelled by the toxic skin secretions of this frog, but some snakes may be able to eat them. The tadpoles are also prey to damselfly nymphs.

• Anti-predator Adaptations
• aposematic aposematic

Ecosystem Roles

These animals, along with all other animals, play an important role in maintaining the balance of nature. They are predators of ants, termites, tiny beetles, crickets, and other small insects and spiders. They are prey to snakes.

Economic Importance for Humans: Positive

Dendrobates leucomelas helps keep its prey populations in balance, and consumes many insects that humans would consider pests. Along with other poison dart frogs in the family Dendrobatidae, this frog is used in medical research because its complex skin toxins are a possible source of medicines for human diseases. Also, certain Dendrobatid frogs were of importance to the Colombian Choco Indians who used the poisons from the frog's skin to tip their hunting darts.

Some amphibian hobbyists keep and breed these and other poison dart frogs, which may have an economic benefit if such trade can be shown to be sustainable and does not reduce natural frog populations.

• Positive Impacts
• pet trade pet trade
• source of medicine or drug source of medicine or drug
• research and education
• controls pest population

Economic Importance for Humans: Negative

These frogs have no adverse economic impact to humans. The skin toxins of this frog are very intense, and are are capable of killing, injuring, or impairing humans if the frogs are carelessly handled; however they are of no danger to people who leave the frogs alone.

• Negative Impacts
• injures humans
  • poisonous poisonous

Conservation Status

These frogs are not thought to be an especial conservation concern. They are listed on CITES appendix II, probably because of exploitation and destruction of their habitat for lumber.

Additional Links

AmphibiaWeb

Encyclopedia of Life

Contributors

Lisa Brennan (author), Michigan State University, James Harding (editor, instructor), Michigan State University, Nancy Shefferly (editor), Animal Diversity Web.

References

Bartlett, R. 2003. Poison Dart Frogs . Hauppauge, New York, USA: Barron's Educational Series, Inc..

Doyle, D. 1999. "Doyle's Dart Den" (On-line). Accessed January 05, 2005 at http://www.doylesdartden.com/ .

Lehmann, P. 2003. "Amphibia Web" (On-line). Dendrobates Leucomelas. Accessed December 17, 2004 at http://amphibiaweb.org/cgi-bin/amphib_query?table=amphib&special=one_record&where-genus=Dendrobates&where-species=leucomelas .

Staniszewski, M. 1995. Amphibians in Captivity . Neptune City, New Jersey, USA: T.F.H. Publications, Inc..

Walls, J. 1994. Jewels of the Rainforest . Neptune City, N.J.: J.F.H. Publications.

Woodland Zoo, 2001. "Animal Fact Sheet" (On-line). Poison Dart Frog. Accessed December 22, 2004 at http://www.zoo.org/educate/fact_sheets/psn_frog/psn_frog.htm .

2003. "Honolulu Zoo" (On-line). Yellow Banded Dart Frog. Accessed December 17, 2004 at http://www.honoluluzoo.org/yellow-banded_dart_frog.htm .