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Elephants 'understand human gesture'

What it is: Scientists have discovered that African elephants are able to understand human gestures instinctively, irrespective of whether they have been trained to do so.

The 11 elephants used for the experiment had received some training to follow basic vocal commands but not gestures.

In each experiment, two identical buckets were placed in front of the animal and a researcher would point to with her hand the bucket that contained a treat. The elephant, though not able to see the treat itself, chose the right bucket with its trunk 67.5 per cent of the time. This is comparable to human babies, who do so 70 per cent of the time.

According to the BBC, this makes elephants the only non-human animals to understand gesture without training. It is interesting how despite being evolutionarily distant from human beings (last shared ancestor: 100 million years back), elephants have many human-like abilities: they weep for their dead, recognise themselves in mirrors.

Why it matters: This research may help us understand how humans have managed to tame elephants despite them being generally large, dangerous and unmanageable. If elephant trunk movements are proved to be a form of gesture rather than them simply sniffing the breeze, then we may be able to decipher how wild elephants communicate.

Why a jellyfish is the ocean's most efficient swimmer

What it is: A study has revealed that the moon jellyfish, a common nuisance to swimmers, may just be the most efficient swimmers on Earth!

In a project funded by the U.S. Navy, marine biologists observed and analysed the two phases of the swimming motion of these blob-like creatures. The first phase involved the jellyfish contracting its open bell, pushing the water behind it and propelling itself forward. In the second phase, the bell returns to its original shape and fills with water again.

Closer examination of the energy expenditure in the second phase showed that the jellyfish was not doing any work at that time. The elasticity of its bell was letting it move its muscles and travel further at no extra energy cost.

The moon jellyfish thus spends the less energy to swim a particular distance for its mass than any other creature.

Why it matters: Large blooms of jellyfish have been known to displace shoals of fish, which was surprising considering how much more agile these fish seem to be. This discovery may explain how that is possible. Moreover, the U.S. Navy is interested because this technique could be exploited to design ocean-going machines which can function longer without extra batteries or maintenance.

Compiled by Nandita Jayaraj

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