#Blue planet ii season 2 episode 5 series#

It depends on definitions that we make up, and those definitions need to serve a scientific purpose. In reality, the line between ‘true tool use’ and actions like Percy’s is often blurry.

#Blue planet ii season 2 episode 5 series#

Photo by Michael HaslamĮmphasising such a subtle difference can seem quite unfair to Percy, who after all is engaging in a whole series of complicated actions to get an otherwise inaccessible meal. If Percy picked up a piece of coral and beat it against the clam, then the coral would be a tool, the same as stone tools used by various wild primates to open nuts and molluscs.Ī wild sea otter breaks a mussel against a rock. In this way her behaviour resembles that of animals such as New Caledonian crows that drop nuts onto stone anvils to break them, or sea otters that pound mussels against a rock. The coral against which she throws her clam is stationary and she doesn’t even need to touch it. If we insist that a tool needs to be held and manipulated to cause a change to something else, then Percy isn’t in fact a tool user. As a result, humans can now fly too, whether by hang-glider, helicopter, dirigible, rocket, aeroplane, hot-air balloon or even various types of personal jetpack.

But tools allow for much greater flexibility and don’t rely on the very long-timescales and random pathways of evolution. Most animals deal with such issues through adaptations to their bodies, such as insects, bats and birds independently developing wings for flight. Leaving aside our own self-importance, what is it that makes tool use special? The key seems to be an ability to control one part of the environment while using it to change something else – hammering a nail into a board, or using a sail to catch the wind. Yet there is an understandable reluctance to see the simple stick tools of chimpanzees, for example, as somehow equivalent to our carts, cars and spacecraft. Starting with observations in the mid-twentieth century, we now know that in fact hundreds of other species use tools, from spiders to octopuses to monkeys. In part, this question is a result of a long-held view that humans were special because we use tools and other animals do not. But is tool use the right term to describe Percy’s clam-smashing? Or is it something better described as object handling or prey manipulation? It may seem like a fine distinction, but there is a serious scientific question underlying these descriptions. Narrator Sir David Attenborough states that Percy is ‘a fish that uses tools’. And this behaviour is likely to be more widespread than we currently know – there are scientific reports from 2011 of an orange-dotted tuskfish doing the same thing in Palau, and of a close relative, the black spot tuskfish, using a rock as an anvil on the Great Barrier Reef. One result is that the coral gets worn down and surrounded by numerous old, broken shells, which will give future scientists clues for finding other sites like Percy’s. The castle has a hardened spot on its inner rim that Percy targets over and over again with the clam, chipping away at the shell until it finally falls apart. But these molluscs are too tough for Percy’s teeth to crush, so instead she goes on a second journey, heading for a specific coral group that the producers called the ‘castle’. She then grabs the shell with her protruding front teeth, at which point most predators would simply eat their captured prey. She starts this process by searching out across the coral beds and sand flats for buried clams, which she discovers by blowing away the covering sand. In any case, Percy’s particular claim to fame is her ability to open clams by throwing and striking them against hard coral, breaking them apart.

This sex-change operation was shown in the same episode for one of Percy’s wrasse relatives, the kobudai of Japan.

Granted, she was female at time of filming the series-opening episode One Ocean, but larger females of her species are known to change sex when it would give them an evolutionary advantage. And it’s not entirely clear that she’s a female fish either.

More precisely, she’s an orange-dotted tuskfish ( Choerodon anchorago also known as an anchor tuskfish) living in the warm waters of Australia’s Great Barrier Reef. Unlike most contributors, however, and despite a somewhat wonky grin, Percy gets to spend time in front of the camera. Just like thousands of other hard-working individuals, she put considerable time and effort into ensuring that Blue Planet II - the new BBC series that started on 29 October – is the most extraordinary window into the life of our planet’s oceans that anyone has ever seen.