The American Tree Frog and Amplexus

The American Tree Frog (Hyla cinerea) likes to make noise to attract their mates. Courtship begins with the male croaking into the wilderness.  A female will come to the male, and if she finds him attractive, they will mate, which I will get into later. As you can see in the picture below, the two frogs mating do not look exactly the same, which is the case in a lot of other animals.

American Tree Frog Demonstrating Amplexus, Photo Credit: Fredlyfish4

There is sexual dimorphism between the males and the females, which means that there are physical and visual differences between males and females of a species. An obvious example of this would be peacocks, where the males have brilliantly-coloured tail plumage and the females are blandly coloured. In the case of the American Tree Frog, the females are larger than the males. What does this mean for how they do the do?

The American Tree Frog copulates using a technique called amplexus. The male will climb on top of the female and hold her very tight to bring their cloacal openings into contact. A cloacal opening is for expelling waste, eggs, sperm.

By bringing the openings close together, the male can fertilize the eggs. Males deposit sperm onto the eggs as they are being laid. But there’s no monogamy here; to increase their chances of offspring, the males will mate with as many females as they can.  Females will often only have their eggs fertilized once a breeding season, but sometimes they will mate several times and lay multiple batches of eggs.

Interested in learning more about the mating behaviours of different plants, animals, and fungi? Check back here for more Mating Mondays.

 For more information about tetrapods like the American Tree Frog, check out the Cowan Tetrapod Collection