African elephants are known for their expressive facial features and skillful trunks that can grasp even small objects with their pincer grip.
Now scientists have discovered the secret of their skill.
The species has the largest number of facial neurons of any land mammal, allowing them to deftly move their ears and perform intricate maneuvers with their trunks.
Facial neurons create a path from the brain to the muscles and, in humans, allow for expressions such as smiling, frowning or raising the eyebrows. The more they are present, the more control an animal has over its facial musculature.
Yet humans only have around 9,000 facial neurons compared to African elephants which have around 63,000.
Experts believe these tens of thousands of extra-facial brain cells are responsible for the extreme feats of trunk, ear and lip dexterity exhibited by African elephants. Animals are only capable of plucking one blade of grass.
Researchers even think they have found the part of the brain responsible for their deft pinching motion that allows elephants to pick up objects: a cluster of very large brain cells found at one end of a group of neurons that control the muscles of the trunk.
High-density cell regions in the brain
Professor Michael Brecht, of the Berlin School of Mind and Brain, of Humboldt University and of the Leibniz Institute for Zoo and Wildlife Research, said: “We see high-density cellular regions in the brains of African elephants, which appear to represent their ‘trunks- fingers ”.
“In African elephants these proboscis fingers are very skilled because they pinch objects.
“We think elephants have such giant neurons because these cells have to extend very long cables to reach the tip of the trunk.”
The discovery was made by comparing the brains of eight African and Asian elephants from German zoos.
The project took more than a decade because the team had to wait for the animals to die before they could study the anatomy of the brain.
The researchers found that Asian elephants had far fewer facial neurons than their African counterparts – around 54,000 – which appeared to be linked to less control of the trunk and ears.
Asian elephants have smaller ears and don’t have finger-like tips at the end of the trunk, which means they have to wrap their entire trunk around an object to pick it up.
They believe that the extra neurons in African elephants show that their brains and trunk have evolved together, allowing for greater dexterity.
Elephant trunks are also super sensitive to odors and can detect vibrations as well as having the strength to cut down trees.
The team found that dolphins are the only mammals that have multiple facial neurons, although the researchers aren’t sure if they’re needed.
Professor Brecht added: “I wonder if this large number of neurons in the facial nucleus are involved in the control of vocalization (which is very complex in dolphins).
“I don’t think they use these neurons for facial gestures, which apparently aren’t that complex in dolphins.”
The research was published in the journal Science Advances.