City frogs act sexier than ones in country

Urban dwellers sing more alluring songs to get mates

WASHINGTON — City frogs and rainforest frogs don’t sing the same tune, researchers have found.

A study released this week examined why Panama’s tiny tungara frogs adapt their mating calls in urban areas — an unexpected example of how animals change communication strategies when cities encroach on forests.

These frogs take advantage of the relative absence of eavesdropping predators in cities to belt out longer love songs, which are more alluring to female frogs.

Tungara frogs don’t croak like American bullfrogs. To human ears, their distinctive call sounds like a low-pitched, video-game beep. To female frogs, it sounds like pillow talk.

Every evening at sunset, the 1-inch male brown frogs crawl into puddles to serenade prospective mates. The lady frog selects a mate largely based on his love song.

Researchers found that the urban frogs call faster, more frequently and add more embellishments — a series of staccato “chucks” on the end of the initial whine — compared with those in the forest.

Those fancy urban love songs are three times more likely to attract the ladies, as scientists learned by playing back recordings of both city and forest frog calls to an audience of female frogs in a laboratory. Thirty of 40 female frogs hopped over to the speaker playing the urban frog calls, the researchers report in the journal Nature Ecology & Evolution.