rhamphotheca:

Do Dolphins Speak Whale in Their Sleep ?

by Sara Reardon

Péos, Mininos, Cécil, Teha, and Amtan are performing dolphins at the Planète Sauvage dolphinarium in Port-Saint-Père, France. Every day, as music and sounds of the sea play in the background, they show off their swimming, jumping, and ball-catching skills for an adoring audience and squawk and whistle just like dolphins should. But at night, they make strange noises that researchers believe are imitations of humpback whale songs included in the performance soundtrack. If so, the identification of this unexpected repertoire would mark the first time that dolphins have been heard to rehearse new sounds hours after hearing them rather than right away, providing insights into how they store and process memories.

Researchers discovered the dolphins’ midnight melodies by accident. Ethologist Martine Hausberger of the University of Rennes 1 in France and her colleagues had hung underwater microphones in the tank because little is known about what dolphins sound like at night. One night, they suddenly heard 25 new sounds (see below) that the dolphins had never made before, although they weren’t sure which of the five animals was talking. Because dolphins are known for mimicry, the researchers examined their complex daytime environment to determine where the noises might be coming from. They finally zeroed in on the new soundtrack that Planète Sauvage was playing during performances, which included music, sea gulls’ calls, the dolphins’ own whistles, and humpback whale calls…

(read more: Science NOW)     (image: Planete Sauvage)