PARIS -- A species of Asian frog can cleverly adapt the tone of its mating call to ensure that it booms out across the jungle to lure a mate, scientists have found.

The male Bornean tree-hole frog (metaphrynella sundana), is the first known case of an animal that is able to test its acoustic environment and then alter its call accordingly AFP reported.

The frogs lurk in hollow tree trunks that are partially filled with water, and send out pulse-like songs to lure females. The farther the distance, the more attractive they are to a prospective mate.

Bjoen Lardner of the Field Museum of Natural History and Maklarin Bin Lakim of Malaysia's Sabah sarks, seeking to simulate those conditions, placed a calling male in an opaque tube that was partially filled with water.

The following night, the depth of water in the tube was subtly lowered, falling by 94mm (37.5 inches) over 28 minutes, which of course increased the amount of air in the pipe and thus changed the acoustics.

The frog masterfully overcame the changing environment, sending out come-hither calls with varying pitches until it found the tone that gave him the right resonance.

As soon as the resonance changed because of the falling water level, the amphibian patiently went through the test procedure again until it found the right booming pitch.

"Several crickets and burrowing frogs benefit from sound amplification by calling from baffles and burrows," the pair report in today's issue of ***Nature****, the British science weekly. "However, to our knowledge this is the first evidence of an animal not only sampling resonance properties but also facultatively adjusting its call pitch and calling strategy in what seems to be an adaptive manner."

Animals may be better at exploiting signal-enhancing structures than was previously thought, they add.