I'll admit it soon: I'm from the village. And yet I got a woman, as we say. But if I were a Tungara frog, finding a partner could have complicated things. Because as a Tungara frog from the countryside, I would probably not be able to express myself as well as my male competition from the city.

It is precisely this mechanism that researchers have discovered in the common species of South and Central America. The brown-greenish and about three centimeters large animals live both in urban areas and in rural areas. They prefer smaller ponds or flooded grasslands as a habitat. At mating season they squat in ponds at night and try to attract females with pronounced sounds.

The courtship sounds of the animals are remarkably complex. They start with a kind of hay-breeze, then other components are added, so-called chucks, the females react to these sounds especially, scientists have found in earlier studies.

A team led by Wouter Halfwerk from the Dutch Vrije University in Amsterdam has now listened to how the calls for the Tungara frogs (Engystomops pustulosus) differ from urban and more rural regions. For this, the researchers observed the behavior of frogs from eleven original and eleven populated areas from Panama. The biologists wanted to know what influence the urban environment has on the communicative ability of the animals.

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Panama: comeback of the frogs

Indeed, the researchers in the study, which in the journal "Nature Ecology & Evolution" was released, the sounds of the city frogs are much more complex. In addition, they call more often than their male conspecifics from the wild.

This has consequences for mating behavior, the experts write. Because apparently Froschweibchen find the calls of the city frogs much more interesting. This was stated by the scientists when they played calls made in laboratory experiments to the Tungara female.

The biologists suggest that environmental noise as well as sensory changes, such as street light, have caused changes in animal behavior. In addition, urban frogs could afford to shout more frequently because in the urban environment they have fewer predators like bats than in the wilderness.

However, the researchers made another experiment: they exposed the urban frogs in rural areas and vice versa, the land eggs in populated areas. Now, the city men adapted to their new environment: they reduced the complexity of their reputation. In contrast, the land frogs did not succeed in the city.

The researchers suspect that the adaptive capacity of animals has been more focused on urban space over time. Because the animals have the experience: Even loud calls for females does not necessarily attract more voracious bats.