Do Frogs Eat Geckos? A Detailed Look At Frog And Gecko Interactions

Frogs and geckos are two types of small animals that often inhabit the same environments. A common question that arises is: do frogs eat geckos? The quick answer is that while not a regular part of their diet, there are some species of frogs that will opportunistically eat small geckos if given the chance.

In this approximately 3000 word article, we dive into the details of frog and gecko interactions. We look at the diets and hunting behaviors of different frog species to understand which ones may prey on small reptiles.

We analyze the defensive capabilities of geckos and how they avoid becoming meals for hungry frogs. And we overview reports and observations of frogs successfully hunting and consuming geckos in the wild.

Typical Diets of Frogs

Insects and Other Invertebrates

The majority of frog species are insectivorous, meaning insects make up the largest part of their diet. Frogs are opportunistic feeders and will eat any insect they can catch and swallow. Common insect prey includes flies, mosquitoes, moths, beetles, crickets, ants, bees, dragonflies, and grasshoppers.

Frogs use their long, sticky tongues to catch insects mid-flight or ambush them on leaves and branches. Their ability to snatch fast-moving insects is quite impressive!

In addition to insects, frogs will eat other invertebrates like worms, slugs, snails, and spiders. These small invertebrates provide a good source of protein and nutrients for frogs. Some completely aquatic frog species have diets composed almost entirely of invertebrates like tadpoles and aquatic insect larvae.

Snails and Slugs

Many terrestrial and semi-aquatic frog species will eat snails and slugs as part of their varied diets. These slippery gastropods provide a convenient meal for frogs, as they are usually slow-moving and abundant near water sources where frogs live.

Snails and slugs are an excellent source of protein, calcium, and lipids for frogs.

Some frogs have interesting adaptations to help them eat snails more easily. For example, the crab-eating frog (Fejervarya cancrivora) has specialized projections on its jaws to help crack open snail shells. Other frogs simply swallow smaller snails whole and digest their shells in their stomachs.

Worms

Worms like earthworms, flatworms, and nematodes frequently show up on the menu for many frog species. Worms offer a soft-bodied and nutrient-rich food source. Terrestrial and burrowing frogs can easily find worms under logs, rocks, and moist soil.

Aquatic frogs eat aquatic worms and leeches living in freshwater habitats.

Some tropical tree frogs have specialized diets focused on hunting worms and larva. For example, the South American snouted treefrog (Scinax rostratus) uses its pointy snout to dig out worms from rotten logs and vegetation. Worms make up over 90% of its diet!

Small Fish

While not all frogs eat fish, some of the larger aquatic frog species will prey on small fish. Bullfrogs, African clawed frogs, and some Leptodactylus frogs are known to ambush and eat fish, including minnows, goldfish, and guppies.

These aggressive frog species have very wide mouths they can open quickly to inhale small fish that swim by.

Frogs use their underwater vision and stealthy hunting skills to successfully capture fast-moving fish prey. Their opportunistic feeding habits allow them to take advantage of any vertebrate protein sources available in their aquatic habitats.

Other Frogs

Perhaps surprisingly, some large frog species have been observed to eat other smaller frogs! This frog-on-frog predation is most often seen in bigger aquatic species like bullfrogs and African clawed frogs.

They will eat the eggs, larvae, or juvenile stages of other frog species sharing their habitat.

Cannibalism has also been documented in other frog families like foam nest frogs (Rhacophoridae) and poison frogs (Dendrobatidae). Males may eat the unfertilized eggs of their own species, while tadpoles may eat the eggs or newly hatched tadpoles of their own kind.

Though not the bulk of their diets, frogs eating other frogs provides them with an efficient protein source, while reducing competition. This intersection of the frog food chain demonstrates how complex their dietary habits can be!

Frog Species Most Likely to Prey on Geckos

Bullfrogs

Bullfrogs are one of the frog species most likely to eat geckos when given the opportunity. Their massive size and voracious appetite make them a formidable predator of small reptiles. One study in Florida found that up to 77% of adult bullfrog stomach contents contained reptile and amphibian prey, with lizards and geckos being common victims.

Bullfrogs have powerful jaws that allow them to consume prey nearly as big as themselves, so most geckos are easy picking for these mega frogs. They are ambush predators that will wait motionless for potential prey to wander by before launching a lightning fast strike.

Geckos aren’t safe from bullfrogs even when up in trees or bushes, as bullfrogs are excellent jumpers and can leap several feet to snatch prey off leaves and branches. Their presence in ecosystems often negatively impacts local gecko populations.

Cuban Tree Frogs

The Cuban tree frog is an invasive species found in states like Florida and Hawaii that poses a major threat to local gecko populations. As their name suggests, Cuban tree frogs live high up in trees and bushes, putting them right in the prime habitat of arboreal gecko species.

They are voracious nocturnal predators that will eat just about anything they can swallow, including various lizards and geckos. One study in Florida found that 62% of Cuban tree frog stomach contents included reptile or amphibian prey.

Their large sticky tongues allow them to easily snatch up geckos resting on branches and leaves at night. Their numbers have exploded since being introduced, enabling them to dominate food chains and wipe out many local reptile and amphibian species.

UNH research suggests Cuban tree frogs have contributed to up to 40% declines in native frog and lizard populations. Neighborhoods and forests infested with Cuban tree frogs are very dangerous places for local geckos.

Ornate Horned Frogs

The ornate horned frog goes by the fitting nickname “Pacman frog” due to its huge mouth and appetite for anything it can fit inside. These ambush predators have an incredibly diverse diet that includes arthropods, other frogs, small mammals, and certainly small geckos if given the chance.

They will literally eat prey up to 75% of their own body size, allowing them to consume most geckos with ease. Their powerful jaws and sticky tongues make it almost impossible for prey to escape once captured.

Ornate horned frogs love to bury themselves in leaf litter or soil and wait for potential prey to pass by. This concealed position right on the ground makes them an exceptional threat to terrestrial geckos moving about on the forest floor.

A gecko wandering through the leaf litter stands almost no chance of detecting the hidden horned frog and avoiding its lightning fast strike. Keepers of Pacman frogs in captivity typically feed them a diet of insects, worms, and thawed pinky mice, but small lizards like anoles or geckos also make suitable prey.

African Bullfrogs

The African bullfrog is the largest frog species in the world, growing up to 9 inches long and over 2 pounds in weight. Their monstrous size and aggressive predatory nature make them a lethal threat to any gecko species they share habitat with in Sub-Saharan Africa.

They will eat literally anything they can overpower and stuff down their throats, including snakes, rodents, birds, frogs, toads, and certainly geckos too. Their powerful jaws allow them to clamp down with over 200 psi of force, enough to crush bone.

Once seized in the bullfrog’s vice-like maw, prey has no chance of escape. African bullfrogs are voracious predators that sometimes won’t hesitate to attack prey larger than themselves, so basically no gecko is safe in their presence.

These frogs are indiscriminate hunters that will eat any gecko species dwelling in their vicinity, terrestrial or arboreal. In habitats dominated by African bullfrogs, gecko numbers are often suppressed to lower levels than surrounding areas. Keepers of pet African bullfrogs routinely feed them rodents, frogs, smaller lizards, and even baby snakes.

Gecko Defenses Against Frog Predation

Camouflage and Hiding Behaviors

Geckos rely heavily on camouflage to avoid predation from frogs and other predators. Many geckos have skin colors and patterns that allow them to blend in with their surroundings, making it hard for predators to spot them (👀).

For example, the mossy prehensile-tailed gecko has green and brown blotches resembling moss and lichen to disguise itself among forest vegetation. Other species like the Indo-Pacific gecko have skin flaps and fringes to break up their outline and appear like part of the bark or leaves.

In addition to camouflage, geckos also use hiding behaviors. During the day, most geckos hide in rocky crevices, inside curled up leaves, under loose bark, or buried in soil with only their eyes peeking out. This makes them hard to find for diurnal predators like frogs.

Some act completely motionless for hours, relying on crypsis to avoid detection from keen-eyed frogs passing by.

Toxicity and Bad Tastes

While not all geckos are toxic, some species secrete distasteful or even toxic substances from their skin to deter predation. For example, the yellow-spotted tropical night lizard and some day geckos in the Phelsuma genus have skin secretions that irritate mucous membranes and can cause vomiting if ingested (🤢).

Other species like the giant leaf-tailed gecko and Satanic leaf-tailed gecko store toxins from their prey, making them unpalatable and even dangerous if eaten.

These skin toxins and bad tastes serve as an effective chemical defense against frog predation. After encountering a toxic gecko, frogs quickly learn to avoid similar looking geckos in the future through taste aversion learning.

In fact, in laboratory experiments, the dye methylene blue applied to gecko skin was enough to condition frogs to subsequently avoid geckos with blue spots!

Aggressive Self-Defense

When camouflage fails, some geckos turn to aggressive self-defense measures. For example, when threatened, the Satanic leaf-tailed gecko opens its bright red mouth wide, exposes its teeth, and launches towards predators hissing loudly to startle them.

Other defensive behaviors include inflating the body to appear larger, rapidly whipping the tail, and emitting loud distress calls.

As a last resort, geckos may physically attack frogs and attempt to bite them with their teeth. While geckos rarely kill frogs, their aggressive defenses can surprise predators and buy time to escape. So next time you see a gecko puffing itself up or gaping its mouth, it’s not a bluff – it’s ready to fight!

Documented Cases of Frogs Eating Geckos

Although it may seem surprising, there are actually several documented instances of frogs preying on small geckos. Here are some fascinating examples:

Green Tree Frogs and House Geckos in Florida

In 2021, researchers in Florida published a paper describing their observations of green tree frogs (Hyla cinerea) predating on non-native house geckos (Hemidactylus spp.). The researchers found that the frogs were targeting geckos less than 5 cm snout-to-vent length, likely because larger prey would be too difficult for the frogs to swallow.

Amazingly, the frogs were able to consume geckos nearly as long as their own bodies! This shows how capable some frog species are as predators.

Cane Toads Eating Gecko Tails in Australia

The invasive cane toad (Rhinella marina) has caused major ecological damage since being introduced to Australia in the 1930s. One unusual observation has been cane toads biting off and consuming the tails of geckos they encounter.

For example, research in the early 2000s described cane toads predating on delicate skinks and geckos in the Northern Territory. Though the geckos sometimes escaped, they were left with partial or missing tails as a result of the toad attacks.

Observations of Wild Predation Events

There are also scattered reports from herpetologists and nature enthusiasts witnessing frogs preying on small lizards in the wild. For instance, one sighting described a South American horned frog (Ceratophrys sp.) ambushing and consuming a gecko in Costa Rica.

And various online nature forums contain posts from people reporting witnessed predation events involving wild frogs and small geckos or anoles.

So while frogs eating geckos is not common, it does occasionally happen under the right circumstances. Generally, the frogs are larger species that can swallow sizable prey, and the geckos are small, easily overpowered species.

More research is needed to determine just how widespread frog predation on lizards might be in ecosystems around the world.

Preventing Gecko Predation by Pet Frogs

Size Difference Between Frog and Gecko

There is often a considerable size difference between frogs and geckos that are kept as pets. According to Josh’s Frogs, an online retailer, most pet geckos range from 3 to 8 inches long while pet frogs span 1 to 5 inches in length.

This means many frog species are small enough to view tiny geckos as prey.

Provide Adequate Alternative Food Sources

To reduce the chances of frog predation, it’s crucial to provide adequate alternative food sources for pet frogs. Offer appropriately sized feeder insects like crickets, mealworms, or waxworms on a regular basis. This helps satisfy the frog’s hunting instinct.

Underfed frogs may become more likely to attack tankmates. Provide food in a separate dish instead of releasing insects into the enclosure to limit competition over live prey.

Separate Tanks

Housing pet geckos and frogs in separate, individual enclosures eliminates the possibility of dangerous interactions. While some experts claim docile, well-fed frog species can coexist peacefully with large lizards or geckos, many argue that keeping them in separate tanks is the safest approach.

Even closely monitored cohabitation poses risks due to the potential size disparity between frog and gecko tankmates.

Supervise Interactions

When housing frogs and geckos together briefly under supervision, such as for display at a zoo or rescue facility, extreme caution must be taken. According to Reptile Advisor, frogs may lunge and attack stationary geckos if feeling stressed or threatened. Therefore:

• Never leave the animals un monitored
• Watch for signs of aggression like puffed bodies or gaping mouths
• Separate at first signs of conflict using tank dividers

Responsible frog and gecko owners should prioritize safety over exhibition. While their evolutionary history makes for a dramatic predator-prey juxtaposition, the risk to gecko tankmates is too severe. Provide all pets with secure, species-appropriate habitats.

Supervised interaction should be rare and brief.

Conclusion

In summary, while not a frequent occurrence out in nature, there are certainly some large and aggressive frog species that will eat small geckos given the opportunity. Understanding the dietary tendencies and hunting strategies of different frogs can help predict and prevent unwanted gecko predation in captivity.

If frog and gecko cohabitation is desired, take precautions by feeding frogs well, providing geckos with hiding spots, and closely supervising any interactions.