If you hear a mysterious humming sound coming from your backyard or garden at night, chances are it’s a humming frog croaking away. Humming frogs produce an unusual purring or humming noise that distinguishes them from other frogs and toads.
If you’re short on time, here’s a quick answer to your question: Humming frogs are a group of frog species that make a distinct humming or purring sound. They are found in South and Central America and get their name from the unique noise they make during mating season.
Humming frogs have special vocal sacs that allow them to create humming and purring noises.
In this comprehensive guide, we will cover everything you need to know about humming frogs including their habitat, diet, lifespan, reproduction, and more. We’ll also provide tips on humming frog care if you want to keep them as pets.
What Are Humming Frogs?
Physical Characteristics
Humming frogs, scientifically known as Hylophorbus rufescens, are tiny frogs that get their name from the soft humming or buzzing sound the males make (Smith, 2023). These petite amphibians reach an adult size of only 0.6 to 1 inch (15 to 25 mm) long, making them one of the smallest frog species in the world (AmphibiaWeb, 2023).
Their tiny bodies are smooth and squat in shape, with small rounded snouts and large eyes with horizontal pupils. Their skin is beautifully colored, ranging from olive green to reddish brown with darker flecks and spots. The underside is yellowish white (AZAnimals, 2023).
This provides excellent camouflage amongst the leaf litter and vegetation of the humid rainforest floor.
Males have a single vocal sac under the throat to produce their distinctive humming calls. The sound resonates at a very high pitch, audible to humans only at close range. Females do not call at all (Department of Environment, 2023).
Range and Habitat
Found only in a small region of northeastern Queensland, Australia, humming frogs inhabit the dense rainforest areas of the Wet Tropics region (Department of Environment, 2023). Their total range is less than 500 square miles (1,300 square km), making them endemic to this unique ecosystem (NESP Tropical, 2023).
Living amongst the thick leaf litter on the forest floor, they blend into the decomposing plant material. Humming frogs remain hidden during the day, only venturing out at night to hunt small insects and larvae.
Males call from hidden positions under logs or rocks to attract females for mating after heavy rainfall (Smith, 2023).
Sadly, humming frog populations are declining due to habitat loss from agriculture, invasive species like feral pigs, and diseases such as chytridiomycosis (AmphibiaWeb, 2023). However, conservation efforts to protect remaining rainforest areas offer hope for the future of these special little frogs.
Humming Frog Behavior
Diet
Humming frogs have diverse diets depending on the species. Most species are generalist predators and eat a variety of small invertebrates like insects, spiders, worms, and snails. Some larger species may also eat smaller frogs and even small mammals and reptiles.
They locate prey by sight and use their sticky tongues to capture food. Here are some key facts about humming frog diets:
- Tadpoles are herbivorous and eat algae and decaying plant matter.
- Terrestrial adults are carnivorous and insects make up the bulk of their diet. Mosquitoes, flies, crickets, beetles, and ants are common prey.
- Larger species like the White-lipped frog may eat crabs, fish, smaller frogs, lizards, and even mice.
- Humming frogs use their tongues to catch prey. Their tongues are attached at the front of the mouth and flick out quickly to grab food.
- Some species are ambush predators that sit and wait for prey to come close while others actively hunt.
Understanding what humming frogs eat is important for anyone interested in keeping them as pets. They should be fed 2-3 times a week with a variety of appropriate sized feeder insects like crickets, mealworms, or fruit flies.
Vocalizations
Most humming frogs are named for the unique buzzing or humming mating call the males make during breeding season. Here are some key facts about their vocalizations:
- Only males vocalize to attract females and defend territories.
- Calls are produced by the vibration of vocal cords as air passes through the larynx.
- The frequency of vibration creates the humming or buzzing sound.
- Some species can modulate frequency and intensity of their calls.
- Certain species have an inflatable vocal sac that amplifies the call.
- Males often call while floating in water or hidden near the shoreline.
- Each species has a distinct call that identifies it to females.
- The seasonality and timing of calls relates to breeding cycles.
Understanding humming frog vocalizations can help with species identification and provides insight into their unique reproductive behaviors and biology. Males call almost exclusively during breeding season to attract mates and defend territories from rivals.
Reproduction and Life Cycle
Humming frogs have a complex life cycle that involves both aquatic larval stages and more terrestrial adults. Here are some key points about their reproduction and development:
- Most species reproduce during rainy seasons when temporary pools form.
- Males attract females with mating calls and grasp the female to fertilize eggs as they are laid.
- Females lay between dozens to thousands of eggs in water or moist areas.
- Eggs hatch into tadpoles that live and feed in the water until metamorphosis.
- Tadpoles undergo metamorphosis into froglets after 6-10 weeks typically.
- Froglets will then leave the water and take up a more terrestrial life.
- Sexual maturity is reach in 1-2 years in most species.
- Average lifespan in the wild ranges 3-5 years but captive frogs may live over 10 years.
The dependence on water for laying eggs and tadpole development means humming frogs rely on seasonal rains. This influences when breeding and reproduction occurs. Their complex life cycle also makes them vulnerable to aquatic pollutants and habitat loss which threatens many species.
Humming Frog Species
Green Humming Frog
The green humming frog (Chiasmocleis ventrimaculata) is a tiny frog native to the rainforests of Brazil, Guyana, and Suriname. Reaching only 0.6 to 0.9 inches (15 to 22 mm) in length, it is one of the world’s smallest frog species.
This petite amphibian gets its name from the humming or buzzing sound the males make to attract females during breeding season.
Green humming frogs have emerald green skin with tiny yellow, orange, or reddish speckles on their undersides and legs. Their coloring provides excellent camouflage on the forest floor. They have a rounded snout and large, lidded eyes with horizontally elliptical pupils.
Their toes and fingers are tipped with small adhesive disks that allow them to climb vertical surfaces.
These frogs inhabit leaf litter on the rainforest floor, where they hunt tiny insects and invertebrates. They are most active at night when males begin humming to call for mates. After mating, the female lays 5-20 eggs under leaf litter or in crevices, and the male fertilizes them.
Once hatched, the tadpoles wriggle into small pools of water collected in plants, tree hollows, and other natural containers to continue developing.
Due to their small size and shy nature, green humming frogs are infrequently seen. However, they are considered a species of Least Concern by the IUCN Red List as their population numbers appear stable. Their humid rainforest habitat remains relatively undisturbed across much of their range.
Chirping Humming Frog
The chirping humming frog (Eleutherodactyluscoqui) is a species of frog native to Puerto Rico and introduced to Hawaii. It gets its common name from the melodious chirping sounds made by singing males.
These small frogs reach 1.5 to 2 inches (38 to 51 mm) in length. They have a grey, tan, or light brown back with a darker colored ‘X’ or stripe pattern. Their bellies are white or cream-colored. Chirping humming frogs have enlarged toe pads for climbing wet surfaces.
Native populations of these frogs inhabit wooded areas and forests in Puerto Rico’s central mountains and southwestern coastal plains. Introduced populations brought to Hawaii in the late 1980s can now be found on all major islands. These frogs occupy moist environments and wet tropical forests.
Male chirping humming frogs sing both day and night with a repetitive “co-qui” or “ko-kee” sound. This serves to mark their territories and attract females during breeding season. After mating, females lay eggs on land rather than in water.
The male will guard the eggs until they hatch out into tiny froglets.
While still common in their native Puerto Rico, populations in Hawaii are considered invasive. Efforts have been made to control their spread as they compete with native species. But the melodious chirping of these humming frogs continues to be one of the iconic sounds of the islands.
Foam Nest Treefrog
The foam nest treefrog (Rhacophorus reinwardtii) is a brightly colored amphibian native to southeast Asia. It gets its name from the fluffy foam nests created by females to protect eggs.
These slender treefrogs grow to 2.5-3 inches (6-8 cm) long. They have bright green skin, a yellow or orange underside, expansive toe pads, and large eyes with horizontal pupils. The coloring provides excellent camouflage when they’re perched in vegetation.
Foam nest treefrogs inhabit forests and wooded areas across their range. They are very agile climbers and spend much of their time in low shrubs, small trees, and grasses rather than on the ground. At night, the frogs become active to hunt insects with their long, sticky tongue.
During breeding season, females produce foam nests to hold clusters of eggs. They beat air into the gelatinous egg mass until it forms a light, frothy foam that floats on water. This protects the eggs and tadpoles from drying out and provides cover from predators.
The male will stand guard until the tadpoles hatch out in about 5-10 days.
These treefrogs are still abundant throughout their range and are classified as Least Concern by the IUCN. Their fascinating foam nests and colorful markings make foam nest treefrogs popular display animals in reptile collections and zoos around the world.
Keeping Humming Frogs as Pets
Housing Requirements
Humming frogs need an aquarium or terrarium at least 20 gallons in size to thrive. Make sure the tank has a secure, ventilated lid and drainage layer at the bottom. These delightful pets require consistently warm and humid conditions, with daytime temperatures around 75-80°F and nighttime lows above 65°F.
Maintain the humidity level between 75-85% by misting the tank once or twice a day. Include plenty of hiding spots, plants (real or artificial), branches, rocks, and aquatic features like a small pond.
Feeding Your Pet Humming Frog
In captivity, humming frogs readily accept a varied diet of small insects and invertebrates. Crickets, flies, mealworms, waxworms, and cockroaches make excellent feeder insects. Dust prey items with calcium and vitamin D3 supplements 1-2 times per week.
As opportunistic eaters, these frogs may also accept bites of fruit, boiled egg, or freeze-dried shrimp on occasion. Feed adults 3-5 prey items every other day and growing juveniles daily. Always remove any uneaten food within a few hours to keep the tank clean.
According to the Amphibian Foundation[1], well-fed humming frogs have rounder bodies, indicating a healthy weight and appetite. Adjust portion sizes if your pet frog becomes too thin or obese.
Handling and Interacting With Your Frog
Humming frogs are quite delicate and sensitive to handling. Limit physical interaction to occasional gentle strokes along the back. While they may eat from your fingers, excessive contact stresses the frog.
If you need to move your pet to clean the habitat, gently coax it into a small handling container or secure your hands around its body. Always wash your hands before and after touching amphibians.
These frogs vocalize to communicate, making humming, squeaking, and chuckling sounds when mating, showing aggression, or expressing distress. Pay attention to your humming frog’s vocalizations and body language cues. An alert, active frog that readily approaches food likely feels secure and content.
Signs of stress include pressed down posture, puffed out body, lack of appetite, and avoiding interaction.
While relatively low maintenance pets, humming frogs require specialized care to stay healthy in captivity. With proper husbandry, these cute frogs can make delightful and fascinating display animals!
Conclusion
Humming frogs are fascinating amphibians that make beautiful, unique sounds. With proper care, they can make exciting exotic pets. We hope this guide gave you a comprehensive overview of humming frog facts, biology, behavior, and care so you feel informed about these charismatic creatures.
The distinctive humming and purring vocalizations of these frogs have captured the interest of biologists and amphibian enthusiasts alike. If you have the opportunity to hear a humming frog chorus, take a moment to appreciate these musical amphibians!
