Differences Between a Male & Female Frog

Genitalia

• All male and female frogs have different genitalia and internal sexual organs that allow them to breed. The sex organs on a frog are internal, however, so it is often difficult to tell the difference between males and females just by looking at them. Males have two internal testicles and a spermatic canal in which they produce sperm to fertilize the eggs. Female frogs have ovaries, oviducts and uteri. Both males and females have a cloaca, an orifice through which digestive waste and reproductive products, such as eggs and sperm, exit the body. The cloaca is usually more visible in females.

Physical Features

• In many frog species, the external physical features are identical between male and female frogs, but this is not always the case. In many cases, the female is larger than the male because she must carry a large amount of eggs. Males mount the females during breeding, and they are usually smaller so as not to crush the female partner. Females are often darker as well. In many species, males develop tiny pads on their front legs during mating season. Females tend to have thinner arms than males and are usually more plump.

Behavior

• Males and females behave similarly, but in most species only the males sing. They do this during mating season to attract the females. If you hear the frog singing or notice it has a vocal sack, it is most likely a male. In some cases, both males and females sing, but their song is different. Also, only male frogs try to mount other frogs, even if the frog they are mounting is not female. Male frogs will often mount other things such as logs, rocks and even people's shoes, mistaking them for female frogs. If you see a frog behaving this way, it is definitely male.

Mating

• The most obvious difference between male and female frogs is the role they play in mating. During mating, the female is submissive while the male jumps on top of her as she lays her eggs. The male fertilizes the eggs as they are released. Neither males nor females watch over the eggs or take care of the young, who will soon hatch into tadpoles and fend for themselves.

Differences Among Species

• There are some species of frogs that have unique characteristics that differentiate males and females. Male bullfrogs and green frogs, for example, have larger eardrums than their female counterparts. In many tropical frog species, the male frogs have brighter colors than the females. Some frogs, such as African reed frogs, even change sex when the opposite sex is not present.