In the 1980’s female dolphins were first seen using sponges as a foraging tool to protect their noses while digging at the ocean floor for prey. New research, however, conducted by a team from Georgetown University (go Hoyas, biotches!) has taken a much more comprehensive look at this use of tools by dolphins.
So they can use tools. But this dolphin has clearly not yet mastered the use of female contraception.
Professor Janet Mann of Georgetown looked at a population of bottlenose dolphins in Shark Bay in Western Australia to observe the sponging behavior. Only female dolphins were witnessed using sponges as a means to protect their noses while disturbing the ocean floor, and only 11% seemed to display this behavior. When they located prey, the dolphins would drop the sponges and attack it, only to pick back up their tools when they were finished. Professor Mann concluded that females learned this behavior while still weaning (while male dolphins preferred to socialize during this time). She also found that the female dolphins who used sponges (spongers), “were more solitary, spent more time in deep water channel habitats, dived for longer durations, and devoted more time to foraging than non-spongers.”
Previously, chimpanzees were the only vertebrates observed habitually using tools to hunt for prey, so this study has significant ramifications. In fact, Professor Mann told the Daily Mail that the spongers spend “more time hunting with tools than any nonhuman animal.” Probably more than some human animals as well!
Her research can be found in December’s issue of PLoS ONE.