Dolphins distinguish object materials using echolocation

An international team of scientists has demonstrated that bottlenose dolphins (Tursiops truncatus) can distinguish between different materials using only echolocation while swimming. The study, conducted by researchers from the University of Southern Denmark and Loro Parque Fundación, was carried out at the Loro Parque facilities in Tenerife.

Published in The Journal of the Acoustical Society of America, the research shows that dolphins can identify spheres made of plastic, aluminum, brass, or steel, even when the objects are visually identical. By using ultrasonic clicks and analyzing the resulting echoes, the animals construct real-time mental representations of their surroundings.

During the experiments, two dolphins, Achille and Clara, were trained to approach suspended spheres and select the correct material based solely on sound. Researchers used high-sensitivity hydrophones and synchronized underwater cameras to record how the dolphins adjusted their swimming trajectories and echolocation clicks to achieve the task.