She's heading towards the loudest call because loud calls come from big frogs and big is best. Male gliding leaf frogs leap from the treetops. Oh, To slow their descent, they use their huge webbed feet as parachutes. These large tree frogs spend most of their lives in the high canopy and only come down when it's time to breed. Once settled, they begin to serenade their unseen females. Now it's time for the females to make their move. There's no shortage of suitors, but this female has already made her choice.
She's heading towards the loudest call because loud calls come from big frogs, and big is best. But to reach him, she must run the gauntlet of a gang of smaller suitors. Their only chance of mating is to make a sneaky interception. He scored. But with more females arriving all the time, it's not over until the fat frog stops singing. Feet so vital for gliding are now put to other uses. Two's company. threes inconvenient. But in any case, all male frogs are equipped with dry thumbs which enable them to get a vicelike grip on their moist partners.
It's a case of first come, first served. Living in such a humid environment means jungle frogs are less tied to puddles and pools and these even lay their eggs out of water. There's little chance of them drying out. And up here they're safer from predators.