A dolphin using a sponge in its mouth to catch fish

Dolphins may hold sponges in their mouths to protect their nose from rocks and coralLong known to be among the smartest members of the animal kingdom, researchers have discovered that dolphins, like people, use tools to help them hunt and capture their food. Researchers studying dolphins in Shark Bay off the coast of Australia, noticed that more than half of the dolphins hunted for food while holding sponges in their mouth. After capturing a sample collection of dolphins to study, they found that dolphins who used sponges to hunt for food had different diet profiles than dolphins who hunted the good old fashioned way (with bows and arrows). Apparently the dolphins prod the ocean floor with the sponge in order to stir up special types of fish.

“We were blown away as to how strong the differences between tool users and non-tool users were, especially given that these animals live in the same habitat.”

A dolphin using a sponge in its mouth to catch fishThe fish that the dolphins catch using a sponge are bladderless fish who settle into the muddy bottom of the sea floor. They are not a huge prey, but are very nutritious because fish lacking swim bladders typically have a high lipid content. The dolphin stirs up the mud with the sponge causing the hidden fish to emerge from its hiding spot. That fish do not immediately cover themselves back up and the short time that they are exposed gives the dolphin just enough time to drop its sponge, surface to get a breath, and dive again to snag the fish before it covers itself back up.

Researchers also think that the dolphins use sponges to protect their snouts from sharp rocks and hard coral reefs while they speed along the bottom of the ocean floor looking for food. The dolphins rip the sponge from the sea floor and fit it over their beaks just like a person would put a glove on their hand.

It is very rare for animals to use tools to improve their lives – the use of tools is a prominent feature of the human race and one that has helped them survive and flourish. Dolphins however, are extremely smart and are known to possess complex communication skills, can recognize themselves in a mirror, understand sign language, and have been taught to play a musical keyboard.

Update: The lab monkeys insisted that Reeko update the article to point out that scientists believe monkeys occasionally use tools too.  Researchers have observed monkeys using sticks to dig food out of the ground.

Another update: The lab cat insisted that Reeko update the article to point out that they do not use tools, don’t care about tools, and don’t want to talk about tools.  They noted they only want two things: (1) to sleep, and (2) to have their name mentioned in the article along with the monkeys.

And yet another update: Since the lab monkeys and lab cat were mentioned in the article, Reeko felt he should ask the lab rats if they used tools and wanted to be mentioned in the article.  The lab rats responded, “No, we can’t count that high”.

And yet another another update: Since the lab monkeys laughed at the lab rats’ answer to Reeko’s question, the lab rats asked to be given another chance to provide a more intelligent answer.  Reeko asked again, “Do you use tools?”  The lab rats looked at each other, gathered together in a circle to confer, and beaming brightly, came back with their answer.  “No, we can’t count that high.”

Sources: Live Science, Science Magazine
Print Friendly, PDF & Email