11 Fascinating Facts About Anura (Frogs and Toads)

Anura, commonly known as frogs and toads, are a diverse and fascinating order of amphibians. With over 7,000 species found on every continent except Antarctica, these incredible jumpers have captivated humans for centuries. Their bulbous eyes, smooth skin, powerful legs, and signature croaks make them one of the most recognizable creatures on the planet.

Frogs and toads play a vital role in ecosystems by controlling insect populations, serving as an important food source, and indicating environmental health. While we may be familiar with these creatures, there is still much to discover about their biology, evolution, and ecology.

In this article, we’ll explore 11 interesting facts about Anura to gain a deeper appreciation for their diversity and adaptability.

1. Anura is the scientific name for the order including frogs and toads

The order Anura belongs to the class Amphibia and includes all living frogs and toads. The name Anura comes from the Greek words “an-” meaning without and “oura” meaning tail. This refers to the fact that adult frogs and toads lack tails, unlike salamanders and newts.

Anura is divided into three suborders:

Archaeobatrachia – primitive and extinct frogs^[1]
Mesobatrachia – paraphyletic group of mostly extinct intermediates
Neobatrachia – diverse group containing 96% of all extant frog species

There are over 50 families recognized within Anura, the largest being Hylidae (tree frogs), Ranidae (true frogs), and Bufonidae (true toads).

2. There are key differences between frogs and toads

While there is no taxonomic distinction between frogs and toads, there are some key differences:

Skin texture – Frogs have smooth, moist skin while toads have bumpy, dry skin. The drier skin of toads allows them to live in more terrestrial habitats.
Body shape – Frogs tend to have a more slender, hydrodynamic build compared to stockier, shorter-legged toads.
Habitat – Frogs are often semi-aquatic, rarely venturing far from water. Toads are more adapted to dry environments and spend more time on land.
Toxins – Many toads have parotoid glands behind the eyes that secrete toxic secretions as a defense. Frogs lack these poisonous glands.

However, there are exceptions – some toads are highly aquatic while some frogs live far from water. The distinction is not scientifically rigid but rather reflects ecological trends.

3. Anurans inhabit nearly all habitats and regions

A key factor in the success of anurans is their ability to thrive in diverse environments. Different species have adapted to live in:

Tropical rainforests
Deserts
Marshes and swamps
Mountains up to 16,000 feet
The Arctic Circle
Urban areas

Regions without anurans include Antarctica, extremely arid deserts, and some isolated islands.

Tree frogs in tropical forests are arboreal, using their sticky toe pads to climb high into the canopy. Spadefoot toads in dry deserts spend much of their lives underground, emerging only during rainfall. Anurans demonstrate a remarkable ability to adapt to ecological conditions across the world.

4. They have a unique metamorphosis life cycle

Most frog species undergo a distinctive life cycle:

Egg – Eggs are fertilized externally in water. They are laid as clumps or strings containing thousands of eggs.
Tadpole – Hatched tadpoles are entirely aquatic and herbivorous.^[3] They initially lack limbs and breathe through gills.
Adult – Through metamorphosis, tadpoles develop limbs, lungs, lose their tail, and become air-breathing adults. This transformation takes weeks to months depending on the species.

Direct development where the frog morphology appears in eggs without a tadpole stage has also evolved in some lineages. For example, the Puerto Rican coqui frog (Eleutherodactylus coqui) skips the tadpole stage.

5. Anurans are champion jumpers

Australian blue tree frog, litoria (Litoria caerulea).

The strong, elongated hind limbs of frogs and toads power their incredible jumping ability. When muscles in the leg contract, forces over 20 times the frog’s body weight can be generated, launching them into the air.

Some exceptional jumpers include:

Australian rocket frog – Can leap over 10 feet horizontally.^[2]
South African sharp-nosed frog – Jumps up to 13 feet with one bound.
Florida bog frog – Has a recorded horizontal jump of over 6 feet.

Slow-motion video reveals that anurans use their forelimbs and aerodynamic body position to re-angle themselves in mid-air for accurate landings.

6. They employ unique feeding strategies

Anurans have diverse dietary habits and feeding strategies. Their specialized tongues attached at the front of the mouth allow for rapid extension to catch prey. Strategies include:

Sticky tongues to catch insects in flight
Swift strikes to capture aquatic prey
Powerful jaws for subduing large prey
Small teeth for grasping and holding food

Some larger species can even consume small vertebrates including mice, snakes, and hatchling turtles. A few frogs have become carnivorous as tadpoles, eating insects and even small fish.

7. Many secrete toxic or psychoactive compounds from skin

The skins glands of many anuran species produce foul-tasting or toxic secretions that deter predators. Two groups stand out:

Poison dart frogs^[4]– Found in Central and South America, dart frogs sequester plant toxins and produce some of the most poisonous compounds in the world, including batrachotoxin which can be fatal to humans. Their bright colors warn predators.

Psychoactive toads – The Colorado river toad and giant marine toad produce 5-MeO-DMT and bufotenin, compounds that can induce hallucinogenic effects in humans. These secretions are thought to discourage predators.

While ingesting or handling these species can produce severe effects, the poisons are not absorbed through intact human skin.

8. Anurans communicate with unique vocal calls

Male frogs and toads produce loud mating calls using vocal sacs – elastic membranes that amplify sound. Different species have distinctive calls, including:

Distinctive trills of the northern leopard frog
Bass “jug-o-rum” sounds of the American bullfrog
Melodic birdlike calls of tree frogs
Rhythmic underwater clicks of the spadefoot toad

Females are attracted to the male calls. Calls also establish territories between competing males and help tadpoles recognize parents. Anuran vocalizations are among the most diverse acoustic signals in the animal kingdom.

9. Some anurans can change skin color

While most frogs and toads have fixed color patterns, a few remarkable species can change their skin colors by adjusting pigment levels. This helps them:

Camouflage and mimicry – Match the environment by blending in or resembling inedible species.
Thermoregulate – Darken skin to absorb heat, lighten skin to stay cool.
Communicate – Display vivid colors related to territory, courtship, or alarm.

Frogs with notable color-changing abilities include tomato frogs, Australian green tree frogs, and African reed frogs. They accomplish this through cells called chromatophores in their skin.

10. They serve as environmental health indicators

Since anuran skin is permeable and they occupy an important ecological niche, frogs and toads act as bioindicators of environmental health. Declining frog populations can signal:

Habitat destruction
Pollution
Disease
Climate change

Sensitive to slight environmental variations, they are often monitored by scientists as early warning systems for degraded conditions that may affect other wildlife.

11. Anurans show astounding parental care strategies

Most anuran species show little care for eggs or young after laying eggs in water. But some exceptions display remarkable parental instincts:

Male emperor newts patiently wrap fertilized eggs on their hind legs until they hatch.
Male Darwin’s frogs carry tadpoles in their vocal sacs until metamorphosis.
Female gastric-brooding frogs raise tadpoles in their stomachs.

Parental care provides survival advantages in harsh environments. Around 10% of anuran families exhibit some form of post-hatching parental care.

Key Takeaways: Why Anura Are So Amazing

Anura dominates the amphibian world with over 7000 diverse species inhabiting nearly all environments globally.
Key adaptations like strong hind limbs, specialized tongues, and metamorphosis contribute to their success.
Their moist, permeable skins make them excellent environmental indicators sensitive to subtle changes.
Parental care, toxic defenses, color-changing abilities, and extraordinary jumping make some species especially remarkable.
Anuran calls, morphology, and reproduction display astounding diversity unmatched by most animal groups.

Frogs and toads have thrived for 190+ million years through exceptional adaptability. By exploring their many wonders, we gain respect for these superlative amphibians and the importance of protecting their habitats so they can be appreciated for centuries to come.

FAQ

Anura is a group of amphibians, including frogs and toads. It belongs to the order of Anura which includes many species of frogs and other amphibians.

Anurans have external fertilization by sperm deposition and often have morphological features such as large hind legs, a short body, webbed digits, no tail, and presacral vertebrae. Many species also possess cutaneous respiration.

Frogs and toads are found in many parts of the world, except Antarctica. They may inhabit tropical regions, temperate regions, or even boreal areas in northern climates.

There are over 4500 known species of frogs in the world today^[5]. This includes all members of the family Ranidae (true frogs) as well as other families such as Hylidae (treefrogs), Bufonidae (toads), Microhylidae (narrowmouth frogs), Leptodactylidae (clawed frogs), and others.

Yes, there are some differences between a frog and a toad. Generally speaking, most frogs have smooth skin while most toads have rough skin. In addition, some frog species lay their eggs in water while some toads lay their eggs on land.

Amphibians like frogs play an important role in ecosystems by providing food for predators such as birds and small mammals. They also help control insect populations by consuming them. In addition, they can act as indicators of environmental health since they are sensitive to changes in water chemistry or pollution levels.

Many frog species reproduce through external fertilization where sperm is deposited directly onto eggs laid by the female. The eggs then develop into aquatic larvae which undergo metamorphosis into adult form when they reach maturity.

Yes! For example, many South American ‘fuse-tailed’ treefrogs have fused toes which allow them to cling tightly onto branches or twigs during times when they need extra stability due to strong winds or strong currents in rivers. In addition, New Zealand’s endemic fauna includes several unusual bird-like terrestrial frog species known as “kākāriki” that possess bony spines instead of claws on their feet for burrowing into leaf litter.