Sperm whales weigh up to 50 tons, and the smallest bat barely reaches a gram. Nevertheless, the two species share the same success story: They both have developed the ability to use echolocation - a biological sonar - for hunting. Now Danish researchers show that the biosonar of toothed whales and bats share surprisingly many similarities - even though they live in very different environments and vary extremely in size.
Echolocation systems are one of Nature's extremely successful specializations. About 1,100 species of bats and roughly 80 species of toothed whales use the technique this is 25% of all living species of mammals. But why have such different animals as whales and bats both developed the same technique? The reason cannot be found in kinship, as bats and whales are no closer related to each other than all other mammals descended from the same land vertebrates for 200 million years ago.
The answer lies in convergent evolution when almost identical features or developments happen in different species. Through evolution both bats and toothed whales have developed the same functional characteristics.
Researchers from the two Danish universities, Aarhus University and University of Southern Denmark, have now studied the acoustic properties of the technique behind echolocation in bats and whales in the wild. Previous studies of their abilities to locate and catch prey have primarily been based on laboratory tests, and the studies in the wild now provide a much more realistic picture of how the animals use echolocation. The studies have been published in the scientific magazine Physiology entitled "Functional Convergence in Bat and Toothed Whale Biosonars". The authors of the study are Professor Peter Teglberg Madsen from Aarhus University and Professor Annemarie Surlykke from University of Southern Denmark.
"Our studies have shown that the sounds of bats and toothed whales are surprisingly similar. This is due
|Contact: Birgitte Svennevig|
University of Southern Denmark