Tree frogs make a variety of different vocalizations; some are best described as "honks," while others sound similar to "croaks," "whistles" or "barks." Tree frogs make different sounds for different purposes. For example, they usually croak to attract mates, while they may make whistling sounds during rain.
Typically, male frogs find a suitable place for the females to deposit their eggs. Once there, the male begins croaking to attract a female. When the female approaches the male, the male mounts her in a behavior called amplexus. As the female releases the eggs into the water, the male releases sperm, which fertilize the eggs.