Are Frogs Unisex? Compare 4 Methods For Your Frog

Are Frogs Unisex? Sexing Your Frog

Frogs are both Male and Female and It Takes Both of Them to produce fertile eggs that will hatch into tadpoles of both Genders. Their Reproductive organs are hidden within the frog’s body making it very hard visually to tell the difference between the sexes. Male and female frogs can be differentiated during their breeding season.

There are a number of morphological differences on the basis of which the gender of frogs can be identified especially during their mating behavior. The appearance of males and females is usually similar in most of the species with a little clue to identify the gender.

If the males of a particular species are colored bright or dull, then so are the females.

Are Frogs Unisex, Pollution Causing Behavior Modification

Some frogs become unisex due to the effect of a certain chemical.
A recent experiment in California shows that 30 percent of the male frogs that grew up in the water with atrazine started to behave like unisex. The chemicals produced by these frogs attract other male frogs. This chemical is used as a weed killer. That’s the reason this chemical is considered a pollutant of surface water of crops.

Male and Female Frog Size

To put up for the amphibian’s reproductive process called Amplexus, females of many species are larger in size as compared to males. In the mating process, the male rides on the female and remain till she discharges the eggs. The male spreads a top layer of his sperms soon after the discharge of the eggs by the female.

It is believed that the size of the female is larger because she has to support and bear the weight of the male frog during the mating process. The larger body helps her to accommodate a large number of eggs and also supports the transport process. Moreover, the small size of males helps the female to bear his weight and prevents her from crushing during the mating process.

Sexing Frogs

Hidden Reproductive Organs

Male and female frogs have differing genitals, but even this fact is not particularly accessible in determining if an individual frog is male or female. This is because frog genitalia for both genders is housed within the frogs’ body. The male does not possess a penis and the sperms are directly ejected by cloaca onto the eggs.

There are two testicles and the spermatic canal linked to the cloaca. The female body contains ovaries linked to the oviduct which leads to the uterus. Eggs are stored in the uterus for some time before releasing them out of the body and are not involved in the developmental process.

Sexing Toads

Other Physical Differences between the Sexes

There is a small round membrane known as the tympanum membrane which covers the ears of both male and female frogs. Mostly, the circumference of this membrane is larger in males as compared to the size of the eyes. In females, the circumference of this membrane is almost the same as the size of the eye.

Male Gripper Pads

During the mating season, to accommodate the amplexus, males develop the gripper pads on their thumbs.The females do not grow these pads.

Color of Vocal Sacs

Moreover, the throat as well as the vocal sacs of males also turns dark during the mating season and can help to distinguish the males from females. Otherwise, male and female frogs of each species tend to have the same coloring.

Male Only Behaviours in Frogs

A number of behaviors are common in both, males and females, including camouflage and skin shedding as well as eating habits. But there are a couple of behaviors in which only males are involved.

The singing behavior to attract the partner during the mating process is only observed in males. Similarly, only males climb or hug during Amplexus and ride on females.

Male frogs do not restrict performing this behavior to only female frogs but also show the same climbing and holding different substrates like logs, rock, shoes, backpacks, and trees until or unless the mood passes.

How to Identify Gender of your Frog?

First, we have to identify the species of the frog before identifying whether they are male or female. This is because the characteristics vary from species to species.

Appearance, mating behavior, and calls can be good gauges of frog gender if the species is known. If you are unable to identify a frog’s species, consult a veterinarian or other expert who specializes in amphibians.

Appearance: Tips to Differentiate

One of the standard methods is to determine the size of the frog. Usually, the size of the male is smaller as compared to the female in most of the frog species, so can be considered as a standard. In a few species, the males are darker as compared to the females, while in others the females appear darker than the males. Moreover, there are different spots and markings that vary in both males and females.

Size of Tympanum in Male Frogs

You can often identify a male frog from a female by looking at the area next to each eye on the outside of the frog’s body. The area has a cover that appears round in shape and is known as the tympanum or eardrum. The tympanum in males of many species including carpenter frog, bullfrog, and green frog appears larger as compared to the size of the eye while is smaller or of the same size in female frogs

Mating / Male Riding

You can observe frogs’ mating behavior to identify their gender. During the breeding season, the male climbs on the back of the female frog. He hops on both males and females in the process of looking for female mates, but he will stay on a female, climbing onto the female’s back and holding onto her as she lays eggs. During the mating season, male frogs’ throats are darker in color than female frogs’ throats are.

Calls and Sounds / Males and Females

Mostly, it is observed that the sounds are produced by males only to attract the females for the mating process. However, in certain species, frogs of both sexes call. In such species, the sounds produced by both genders are different. 

Male frog calls to attract females.

When male produce sounds to attract the female, the vocal sacs present in his neck inflates and become three times larger as compared to the size of his head. A number of male frogs might sing and produce the sounds at the same time to attract females.

This behavior is sometimes also repeated to keep other males away from the territory and to show their possession of the female.  They typically make most of their vocalizations at night, but you can sometimes hear them calling during the day, too.

Why Your Frog Inflate?

Frogs can puff up other parts of their bodies for various reasons which are as following;

Defensive Posture

Inflating, or making themselves look bigger, can be a defense mechanism used by frogs. When the predator threats a frog, many species inflate themselves to appear bigger in front of their predators. This behavior is to show themselves really big and to show that they are hard to swallow. The tomato frogs of Madagascar show the same behavior as explained by the Exploratorium.

To Avoid Sex

It turns out girl amphibians will use size to their advantage when they are not open to the sexual advances of a potential male suitor. The mating process of the frog is called amplexus in which the male hops on the female’s back and holds her with the fore limbs. They remain in this position while she lays eggs, and he fertilizes them.

To Get Sex

The males usually send messages and sounds for mating, as observed in many species. During the sound production, the vocal sacs are inflated, which helps to amplify their sound when the air rushes in their vocal cords.

To Communicate With Each Other

Sounds produced by the vocal sacs are not always to attract the partner in the mating process. Sometimes these sounds are produced for communication among different members.

Why Frogs Cling on Each Other?

While crossing any water body like rivers or large water puddles, you might have observed two frogs hoping to one another.
This is a behavior called amplexus: it allows the male frog to place his cloaca near the females to fertilize her eggs.

Frog Life Cycle

Starting life as an aquatic, fertilized egg, frogs then emerge from their eggs as tadpoles. The tadpoles slowly develop rear legs and then front legs as they grow. The tadpoles feed on different phytoplankton, a variety of small algal species, small invertebrates, and organic matter as well as other tadpoles.

Frog Reproduction

Most frogs travel to aquatic sites for mating and egg deposition. Once there, male frogs will emit loud advertisement calls; sometimes they must compete with other males for prime locations. The process of fertilization takes place outside the body of females in the external environment.

In a few species, the males hop on the females and spread their sperms soon after the female releases them from their bodies. This fertilizes the eggs. In a few species, the breeding ball behavior is observed in which a single female is encircled by many males, and females are usually drowned during this process.

Asian Frog Farm

Adaptations for Amplexus

The slime on many frogs makes the mating process difficult as the males might slip. The slippery skin appears as a barrier to grip the female properly. To accommodate this hurdle, many males have swollen forelimbs, enlarged thumbs, and the structures to grip the females.

Among other species, leopard frogs, pickerel frogs, and American toads (Bufo americanus) display these structures. In many species, these structures serve as tools to identify gender during the breeding season.

The highly unusual, tailed frog takes amplexus a step further: the tail of these frogs is a copulatory organ that allows these frogs to achieve internal fertilization the only species known to do so.

Release Calls

Frogs do not have very good eyesight, and male frogs are very aggressive breeders. Because of this, male frogs often grab and attempt to achieve amplexus with a variety of things that are not live females of their species.

Mostly, the males hop on the other males of their species and as a result, the releasing calls are made. These calls are made to alert the other male and offend him to release them.

The study showed that in many locations, mixed species breeding opportunities were more common, and produced a great deal of hybrid offspring. Many researchers have documented the males hoping on females of other species and decomposing them as well as with other objects like plastics.


It is difficult to tell the difference in the sexes of male and female frogs. That leads to the assumption that they are unsex. Their reproductive organs are hidden within their bodies. Differences in

  • Size
  • Color
  • Vocal Cords
  • Behavior during Breeding

Frogs/Toads Habitat and Facts

Amphibian Type TypeFoodsAdult SizeVivarium TypeEggs / LiveTemperament
Aggressive - Eat Young
Country OriginPrice
Surinam ToadCarnivorous8"Aquatic100 EggsAggressiveSouth America$ 49.99
Dwarf Clawed FrogCarnivorous1.5"Semi-Aquatic750-1000 EggsSocialAfrica$ 19.50
African Clawed FrogCarnivorous5"Aquatic1000-2000 EggsAggressiveAfrica$ 19.50
European Common FrogCarnivorous4"Semi-Aquatic400-1000 EggsSocialEurope, Central Asia$ 69.99
Leopard FrogCarnivorous3.5"Semi-Aquatic400-1000 EggsAggressiveCanada, Mexico$ 39.99
Ornate Horned FrogCarnivorous5"Tropical Woodland1000 EggsAggressiveArgentina$ 64.99
Painted FrogCarnivorous3"Semi-Aquatic500 EggsAggressiveAsia$ 29.99
Marble FrogInsects2.5"Tropical Woodland200 EggsSocialAfrica?
Southern Tomato FrogCarnivorous4"Tropical Woodland1000 EggsAggressiveAfrica$ 29.99
Golden Mantella FrogInsects1.5"Tropical Woodland20-30 EggsAggressiveAfrica$ 69.99
Poison Arrow frogsInsects1.5"Tropical Woodland5-10 EggsSocialSouth Amewrica$ 44 - $ 99
Eurasian Green Tree FrogInsects2"Tropical Woodland200 EggsAggressiveEurope?
American Green Tree FrogInsects1.5"Tropical Woodland700 EggsAggressiveUSA$ 9.99
American Gray Tree FrogInsects2"Tropical Woodland2000 EggsAggressiveUSA$ 19.99
Red Eyed Tree FrogInsects3"Semi-Aquatic75 EggsAggressiveCentral America$ 49 - $ 174
Red Crevice CreeperCarnivorous2"Semi-Aquatic600 EggsSocialAfrica?
White's Tree FrogCarnivorous4.5"Tropical Woodland150 EggsAggressiveAustralia$ 49 - $ 108
Asian Tree FrogInsects3"Tropical Woodland20-60 EggsAggressiveAsia?
Couche's Spadefoot ToadInsects3"Savannah200-250 EggsAggressiveEurope$ 19.99
Common European ToadCarnivorous6"Temperature Woodland2,000 - 10,000 EggsAggressiveEurope Asia$ 9.99
American ToadCarnivorous3.5Temperature Woodland4,000 - 8,000 EggsAggressiveUSA$ 9.99
Green ToadCarnivorous6"Temperature Woodland12,000 - 18,000 EggsAggressiveAfrica, ASIA$ 11.99
American Green ToadInsects2"Temperature Woodland150 EggsSocialUSA$ 11.99
Red Spotted ToadInsects3"Savannah2000 EggsAggressiveUSA, Mexico$ 9.99
Oak ToadInsects1"Temperature Woodland500-800 EggsSocialNorth America$ 8.99
Giant ToadCarnivorous10"Temperature Woodland20,000-30,000 EggsAggressiveAustralia$ 49.99
Oriental Fire Bellied ToadInsects2"Semi-aquatic300 EggsSocialChina, Korea, USSR$ 15 - $ 25
European Fire Bellied ToadInsects2"Semi-aquatic80-140 EggsSocialEurope$ 99
Yellow Bellied ToadInsects2"Semi-aquatic25-150 EggsSocialEurope$ 49.99
American Bull FrogCarnivorous8"Semi-aquatic12,000-25,000AggressiveNorth America$ 9.99
African Bull FrogCarnivorous8"Savannah10,000 - 12,000 EggsAggressiveAfrica$ 9.99
Asiatic Horned ToadInsects6"Tropical Woodland500-700 EggsAggressiveAsia$ 9.99
Amphibian Type
Adult Size

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