How whistle birds without lips

Whistling caterpillars and five other surprisingly musical animals

In the laboratory experiment, red-shouldered blackbirds approached a tasty portion of mealworms. They triggered a sensor that played the recording of a whistling sound from the caterpillar in question. The birds responded to the whistle by flying away, flinching back and diving. This suggests that the sound startled her.

So while the whistling helps the caterpillar experience the next day, such vocalizations can serve many other functions. Below are five other accomplished whistling artists of nature.

GUINEA PIG

Guinea pigs mainly make noise to communicate with each other and with their owners. For example, a young guinea pig whistles when it is separated from its mother.

But pet owners probably know another reason for guinea pigs whistling: the anticipation of food. Many guinea pigs learn to recognize the signs of an upcoming meal and respond by whistling intensely.

RED DOGS

The particularly social wild dogs that populate the dense forests of Asia in packs are also known as "whistling hunters".

Red dogs pursue cooperative hunting strategies and split up into smaller groups in order to rearrange prey that hide deep in the vegetation. To coordinate their movements in an environment that is both noisy and overgrown, the dogs whistle to each other.

MICE

Male mice produce ultrasonic whistling sounds that are beyond human hearing. They use it to woo females and warn rivals of their territorial borders.

According to a recent study, mice use their windpipes to make these sounds while bypassing their vocal cords - a mechanism that has never been seen in an animal before. In fact, it is similar to how a supersonic aircraft engine works.