Oophaga pumilio

Geographic Range

• Biogeographic Regions
• neotropical neotropical
  • native native

Habitat

Dendrobates pumilio typically live in rainforest habitats and also live in cacao and banana groves, but not banana plantations. Unlike some other Dendrobates, D. pumilio tend to live near the forest floor in leaf litter but they frequently climb trees and vines. Females oviposit on land, but will transport each tadpole to its own water-filled bromeliad to complete metamorphosis. Thus, these frogs require moist, terrestrial habitats with abundant water-filled plants for successful reproduction.

In Nicaragua, Dendrobates pumilio live between 0 to 940 m above sea level and in Panama between 0 to 495 m. Costa Rican populations inhabit similar elevations.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• rainforest rainforest

Physical Description

Dendrobates pumilio are slender frogs with bilateral symmetry. They are small frogs measuring 17 to 24 mm in length at adulthood. They feature four, un-webbed digits on each hand and foot, and the body is overall quite compact. These frogs have fairly large, dark eyes set on the sides of the head. The skin of a poison dart frog is very moist which gives them a somewhat glossy appearance in bright light. This species is sexually monomorphic.

They are typically bright red with blue legs although they vary greatly in coloration, and are known as being one of the most polymorphic, aposematic species. However, populations of D. pumilio tend to be the same color. Though typically strawberry red, the dorsal coloration can vary in color from red to blue, yellow, white, green, black or orange. The dorsal surface may also feature dark spots or mottling. Legs are typically darker and have some degree of blackish mottling. Their aposematic coloration has convergently evolved between some separate populations.

Tadpoles are dark brown above with lighter brown undersides and dark spots scattered throughout. They have small, ventral, oral discs with large, serrated beaks. They can reach 16 mm in length.

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

• Sexual Dimorphism
• sexes alike

Development

Strawberry dart frog zygotes are formed when a male fertilizes eggs from a female. The zygotes divide until they become tadpoles at which point they swim onto their mother’s back and are individually taken to axils of bromeliads. These plants have small pools of water which the tadpoles complete metamorphosis in. The tadpoles require a food source within 3 days of being re-located or they will starve. Females provide unfertilized eggs for the young to consume. Tadpoles begin metamorphosis after growing to 11 mm in length, and the process takes 6 to 8 weeks to complete.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

There is a certain amount of sexual selection for Dendrobates pumilio . Females tend to choose males with similar colored dorsal sides which usually means that they are from the same population. Males tend to have a better chance of mating if their territory is larger, therefore they will compete by wrestling for large territories. Perch height and calling frequency also influence the likelihood of male mating. This may not necessarily be a matter of sexual selection as much as it is good advertising.

In general, D. pumilio are polygynandrous, with both males and females mating with different partners multiple times per breeding season. The female comes to the male by following his call and after a brief period of mutual tactile stimulation the couple breed by egg laying and fertilizing. They assume a vent to vent posture facing away from each other. The whole breeding process takes between 10 and 180 minutes.

There is evidence that these frogs may have some degree of color-vision. Their eyes contain structures required to see different wavelengths, and thus may be able to differentiate between color morphs of their species. This may play a role in sexual selection, but more research must be done.

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

Dendrobates pumilio may breed throughout the year, but only under favorable, moist conditions. Females generally do not ovulate during drier periods and males are less likely to call at this time. After mating, females lay a clutch of 3 to 5 fertilized eggs in moist leaf litter. Under the male's care, the eggs develop into tadpoles after 10 to 14 days, at which time the female take sole responsibility for the young. After being transported to individual, water-filled bromeliads, tadpoles metamporphosize into adults after 43 to 52 days. Both male and female Dendrobates pumilio reach sexual maturity at 10 months of age.

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

Dendrobates pumilio select terrestrial locations to lay eggs, which then require significant additional moisture to avoid dessication. To ensure the clutch is moist, a male will urinate on the eggs on a daily basis. The male also defends the egg clutch, removes fungus, and rotates the eggs before they become tadpoles.

When the eggs hatch after 10 to 14 days, the female transports tadpoles from one to four at a time to a watery hollow in the vegetation (often a water-filled bromeliad). One tadpole is deposited in each location, because they will consume the smaller of their siblings if they are left to grow together. The female strawberry poison frogs must provide food for each tadpole within 3 days of transport or they will starve. Afterwards, she will make morning, daily visits to feed each tadpole 1 to 5 unfertilized eggs. A female will back into the bromeliad and submerge her vent into the pool of water, where the tadpole will stiffen its body and vibrate to solicit eggs. Females will only feed their own tadpoles even if solicited by others.

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

Lifespan/Longevity

Information regarding the life span of strawberry poison frogs is rare, but closely related Dendrobates auratus are known to live up to 17 years in captivity.

Behavior

Male Dendrobates pumilio are known for their aggressive territorial behavior. Males call to establish territories and to determine if there are intruders within these territories. If an intruder responds to the male's territory calls and advances towards the territory holder, the resident male will initiate a wrestling match. A wrestling match may last up to 20 minutes and ends after one frog is pinned down, released and vacates the territory. This occurs more in the morning than in the afternoon. Strawberry poison frogs put most of their energy into feeding, mating, taking care of offspring and defending their territory.

In another interesting show of intraspecific competition, if a male comes upon the clutch of eggs of another strawberry dart frog, it will consume the eggs. If there are small tadpoles in an axil that a male finds, it will allow one to climb on its back and will transport it to a different location where it will starve since it is dependent on the food it receives from its mother.

Strawberry poison frogs are diurnal and are often seen on or near the forest floor. They are particularly active in the mornings. Individuals are mainly solitary but come together to breed or compete for territory. This species generally stays in the same area, and no migratory movements have been observed.

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

Home Range

At the Organization for Tropical Studies at La Selva Biological Station, studies have shown that male D. pumilio defend a territory of 0.24 to 4.78 m squared which includes calling perches, foraging sites, and tadpole rearing sites. Males have been observed to have a home range of 6 to 16 m squared that varies in response to abundance of females. Females occupy larger territories of undocumented size within a home range of 6 to 16 m squared. Females often have larger home ranges which vary in response to abundance of tadpole rearing sites. Other studies at Hitoy-Cerre National Park have shown home ranges to reach 24.5 m squared, possibly reflecting less resource availability.

Communication and Perception

The calls of Dendrobates pumilio consist of a series of short chirps lasting 5 to 32 seconds with 5 to 9 notes per second most often used for territorial announcement by males and for males and females to announce availability for mating. During mating, males and females will engage in mutual tactile stimulation, but unlike many amphibians they do not engage in amplexus.

It has been recently discovered that Dendrobates pumilio feature eyes with unique rods and cones that enable them to differentiate between the many conspecific color morphs. Females rely heavily on this ability to select mates of the same color morph.

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

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

Food Habits

Strawberry poison frogs feed by "wide foraging" in which frogs use their tongues to catch large numbers of small prey. All of their diet consists of small arthropods, some of which (particularly formicine ants) provide toxins which the frogs can excrete through their skin. Dendrobates pumilio consume mostly ants but mites also make up a significant portion of their diet. The tadpoles are oophages, so called because they eat unfertilized eggs either by cutting a hole and sucking the contents out or in the case of larger tadpoles, consume the egg whole. Strawberry poison frogs will typically eat from 7 prey per hour (for juveniles) to 14 prey per hour (adults).

• Primary Diet
• carnivore carnivore
  • insectivore insectivore

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

Predation

Strawberry poison dart frogs have few major predators because their aposematic coloration warns predators that it is very poisonous. However, night ground snakes are immune to the toxins of Dendrobates pumilio . Tadpoles are often consumed because their poison glands are underdeveloped.

• Anti-predator Adaptations
• aposematic aposematic

Ecosystem Roles

Dendrobates pumilo fills a niche of ant and mite population control. They play a significant role in pest control for local plant life. Though the poisonous adults are rarely preyed upon, defenseless tadpoles are likely a food source for predators.

Economic Importance for Humans: Positive

Dendrobates pumilio are sometimes captured (illegally) and sold as pets. As with other species of the genus Dendrobates , D. pumilio secrete a very powerful alkaloid poison which may offer significant medical prospects, but no major breakthroughs have been made. Native human populations use the powerful skin toxins to lace arrow heads, which significantly aids in hunting. The extensive variety of color morphs displayed by Dendrobates pumilio make them an ideal species for research to gain better understanding of aposematic coloration.

• Positive Impacts
• pet trade pet trade
• research and education

Economic Importance for Humans: Negative

There is no negative impact to humans from Dendrbates pumilio .

Conservation Status

Climate change as well as deforestation in the habitat of D. pumilio could have drastic affects as the tadpole rearing process is extremely habitat specific. Strawberry poison frogs are very popular in the pet trade and populations may be threatened by illegal capture. Despite these potential threats, population numbers are currently high and they are considered least concern by the IUCN Red List.

Additional Links

AmphibiaWeb

Encyclopedia of Life

Contributors

Austin Penner (author), University of Alberta, Augustana Campus, Doris Audet (editor), University of Alberta, Augustana Campus, Rachelle Sterling (editor), Special Projects.

References

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