
Borneo Eared Frog
Polypedates otilophus

Meet the Borneo Eared Frog
The Borneo Eared Frog is a striking tree frog native to the rainforests of Borneo, recognized for the prominent, ear-like projections on the sides of its head. This medium-sized amphibian displays a yellowish to brown coloration with dark, irregular markings that provide excellent camouflage among tree branches and leaves. Its large, round eyes and powerful limbs equipped with sticky toe pads make it well-adapted for an arboreal lifestyle. The species is primarily nocturnal, emerging at night to hunt insects and other small invertebrates. During the breeding season, males call from vegetation near water bodies, where eggs are laid above water to protect them from aquatic predators.
Classification
Amphibian
Habitat
Tropical rainforest canopies and forest edges near bodies of freshwater
Diet
Carnivore
Lifespan
5-7 years
Conservation
Least Concern
Weight
10-20 grams
๐Fascinating Facts
Arboreal Expert
Borneo Eared Frogs spend almost their entire lives in trees, rarely descending to the ground except to breed.
Insect Hunter
Their diet consists mainly of insects and other small invertebrates, which they catch using their sticky tongues.
Unique Breeding Strategy
Females lay eggs on leaves overhanging water, so when the tadpoles hatch, they drop directly into the water below.
๐Detailed Description
The Borneo Eared Frog (Polypedates otilophus) is a medium to large-sized arboreal amphibian, with adults typically measuring 60โ90 mm in snout-vent length, and females generally larger than males. Its most distinctive anatomical feature is the pair of prominent, sharp, bony ridges or 'ear-like' projections (squamosal processes) located behind each eye, which may serve as a form of visual deterrent to predators or play a role in intraspecific recognition. The dorsal coloration ranges from pale yellowish to light brown, often with darker transverse bands and irregular markings that provide effective camouflage against tree bark and foliage. The ventral surface is pale and granular. The skin is smooth to slightly granular, especially on the flanks. Its large, protruding eyes possess horizontal pupils, enhancing night vision for its nocturnal lifestyle. The limbs are long and muscular, with well-developed discs on the fingers and toes that facilitate climbing and adherence to smooth surfaces. Webbing is moderate, more pronounced on the toes than fingers, aiding in both arboreal movement and occasional gliding or parachuting between branches. The species is primarily nocturnal, spending daylight hours concealed among leaves or crevices. During the night, it becomes active, moving through the canopy to forage and seek mates. Its vocalizations are loud and metallic, produced by males to attract females during the breeding season. The Borneo Eared Frog exhibits a sit-and-wait predatory strategy, feeding on a variety of invertebrates, and occasionally small vertebrates. It is typically solitary outside of the breeding season, with limited evidence of social aggregation except at breeding sites.
๐ก Did you know?
Unlike most frogs, the Borneo Eared Frog's 'ear' structures are actually bony crests that help distinguish it from closely related species.
๐ฌResearch & Sources
Wikipedia Summary
Polypedates otilophus is a species of frog in the family Rhacophoridae. It is endemic to Borneo where it is widespread and found in Brunei, Indonesia, and Malaysia, typically in the lowlands but sometimes as high as 1,100ย m (3,600ย ft) above sea level. This species has prominent, sharp ridges behind the eye, above the ear, referred to in its names.
Last Modified: 10/28/2022
๐ญBehavior & Social Structure
Polypedates otilophus is predominantly nocturnal, emerging at dusk to forage and call. It exhibits arboreal behavior, rarely descending to the ground except during breeding or heavy rains. The frog uses its adhesive toe pads to navigate complex vertical and horizontal surfaces in the forest canopy. Its hunting strategy is largely ambush-based, remaining motionless and striking rapidly at passing prey, which includes insects such as moths, beetles, and orthopterans, as well as spiders and occasionally smaller frogs. Social interactions are minimal outside the breeding season, with individuals maintaining distinct territories. Males are highly vocal during the rainy season, producing a series of metallic, 'clack'-like calls from perches above water to attract females and deter rival males. Aggressive encounters between males may involve physical posturing and wrestling. The species is sensitive to humidity and temperature, with activity peaking during humid, warm nights.
๐ถReproduction & Life Cycle
Breeding in Polypedates otilophus is closely tied to the onset of the rainy season, typically between November and March, though local rainfall patterns may influence timing. Males congregate near temporary or permanent water bodies, such as ponds, slow-moving streams, or flooded ditches, and call from vegetation 1โ3 meters above the water surface. Amplexus is axillary, with the male grasping the female behind her forelimbs. Females lay clutches of 200โ500 eggs in foamy masses attached to leaves or branches overhanging water. The foam nest, created by vigorous beating of the female's hind legs, protects eggs from desiccation and predation. Embryonic development lasts 7โ10 days, after which tadpoles drop into the water below upon hatching. Tadpoles are free-swimming and undergo metamorphosis over 6โ8 weeks, depending on environmental conditions. There is no parental care post-oviposition, but the strategic placement of nests reduces predation risk.
๐ก๏ธAdaptations & Survival
The Borneo Eared Frog possesses several adaptations for arboreal life, including enlarged toe pads with specialized epithelial cells for adhesion, allowing it to cling to smooth leaves and bark. Its cryptic coloration and irregular dorsal patterning provide camouflage against predators. The pronounced 'ear' projections may serve as a visual deterrent or play a role in species recognition. The foam-nesting reproductive strategy is a key adaptation, reducing egg predation and desiccation. The species' ability to exploit both primary and secondary forests, as well as disturbed habitats near human settlements, demonstrates ecological flexibility. Its vocalizations are adapted for long-distance transmission in dense forest environments, with frequencies that penetrate foliage effectively.
๐Research Sources
๐จCultural Significance
There is limited documentation of specific cultural or mythological significance for Polypedates otilophus among indigenous peoples of Borneo. However, frogs in general are often regarded as symbols of rain, fertility, and transformation in Southeast Asian folklore. The striking appearance of the Borneo Eared Frog has made it a subject of interest among local naturalists and ecotourists, and it occasionally appears in educational materials promoting rainforest conservation.
๐ฌRecent Research & Discoveries
Recent research has focused on the phylogenetic relationships within the genus Polypedates and the Rhacophoridae family, using molecular data to clarify species boundaries and evolutionary history. Studies on the reproductive biology of P. otilophus have provided insights into foam-nesting behavior and embryonic development. Bioacoustic analyses have characterized the species' unique call structure and its role in mate attraction and species recognition. Ongoing ecological monitoring in Borneo is assessing the impact of habitat fragmentation on population dynamics. There is also interest in the frog's skin secretions, which may possess antimicrobial properties of potential biomedical relevance.
๐ฅWildlife Videos

Frogs in the Danum Valley and Muu National Park | Borneo Wildlife
Borneo is home to 156 known species of frogs and toads! This is a compilation of footage and images of a variety of frogs from theย ...
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This is the Borneo Eared Tree Frog. It is an arboreal species of frog that lives on Borneo. It starts out as an egg, then a tadpole,ย ...
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Austin talks about Borneo Eared Frogs
The Borneo Eared Frog has a self-explanatory common name โ it is a tree frog that looks like it has large, spikey ears! These areย ...
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Borneo Eared Tree Frog Habitat
Guess what we found during our morning chores at Finn's Frog Farm?
Finnโs Frog Farm

Josh's Frogs Podcast Episode 27 - Borneo Eared Frogs
Join Josh and Rick in this 27th episode of the Josh's Frogs Podcast as they delve into the world of Borneo Eared Tree Frogs!
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Borneo Eared Frog or Bony Headed Flying Frog - Polypedates otilophus
This interesting frog species can be found in Borneo, Sumatra and other Indonesian Islands. Read more about various frogย ...
Outdoors and Nature Channel
๐Habitat Information
The Borneo Eared Frog typically inhabits Tropical rainforest canopies and forest edges near bodies of freshwater environments. Borneo Eared Frogs have adapted to their environments with specialized features and behaviors.
Primary Habitat:
Tropical rainforest canopies and forest edges near bodies of freshwater
More detailed habitat information will be available soon.
๐ก๏ธConservation Status
The Borneo Eared Frog is currently classified as Least Concern. Conservation efforts are crucial for preserving this species for future generations.
Common Threats:
- ๐ Habitat loss and fragmentation
- ๐ก๏ธClimate change impacts
- ๐ฏHunting and poaching
- ๐ญHuman-wildlife conflict
โ ๏ธThreats & Conservation Challenges
While currently listed as Least Concern by the IUCN, Polypedates otilophus faces localized threats from habitat loss due to deforestation, logging, and conversion of land for agriculture and palm oil plantations in Borneo. Water pollution from agricultural runoff and pesticide use can negatively impact breeding sites and larval development. The species shows some tolerance to habitat disturbance and can persist in secondary forests and near human habitation, but severe fragmentation may isolate populations and reduce genetic diversity. Climate change poses a potential long-term threat by altering rainfall patterns critical for breeding. Collection for the pet trade is not currently a major issue, but could become problematic if demand increases.
๐ฌScientific Classification
Scientific Name
Polypedates otilophus
Classification Hierarchy
๐ About Taxonomic Classification
Taxonomic classification is a hierarchical system used by scientists to classify and organize living organisms based on shared characteristics and evolutionary relationships.
The system moves from broad categories (Kingdom) to increasingly specific ones, with each animal's scientific name typically consisting of its Genus and species.
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