Family RhacophoridaeThis is an extract from Frogs and Frogging in South Africa (Vincent Carruthers and Louis do Preez) “During the rainy season one frequently finds balls of white foam suspended on branches over the water. These are the ingenious nests of the Southern Foam Nest Frog. Before laying her eggs the mating female secretes a fluid that is churned into a stiff froth by continuous movement of the hind legs of the mating pair.
They are joined by several other males who jostle for positions close to the female. After about 15 minutes the female releases the first batch of eggs and they are fertilized by her mating partner. As the eggs are laid, all of the frogs churn them into the foam. The process lasts all night with the female periodically leaving the nest to re-hydrate herself in the water below and frequently changing partners on her return.
The following night she sometimes returns alone to add more foam to the outside of the nest. In sunlight the outer surface of the nest hardens into a crust. The foam protects the eggs from aquatic predators and functions as an isolator, allowing the eggs to develop at an even temperature.”
Info: Frogs and Frogging in South Africa (Vincent Carruthers & Louis du Preez)