Octopuses hurl objects in rare example of animal throwing behavior
Scientists studying the behavior of wild octopuses off the coast of Australia have made a strange discovery, with the creatures caught hurling silt, algae and even shells at one another. The finding sees the cephalopods join just a handful of animals known to throw objects at targets, though the researchers aren’t exactly sure of the motivation for the behavior.
The research was carried out by scientists at the University of Sydney who used stationary GoPro cameras to film octopus behavior in a marine reserve in Jervis Bay on the eastern coast of Australia. The footage collected by the team shows the wild octopuses hurling different items in different scenarios, and at times hitting other octopuses with them.
In some circumstances, the octopuses could be seen throwing away the scraps of their meals or other materials in an apparent attempt to tidy up their living space. In another case, a female octopus repeatedly hurled silt at a male octopus that had tried to mate with her, who dodged the incoming projectiles. The scientists also saw the octopuses throw silt at one of the research cameras, while other throws hit nearby fish.
“Most throws do not hit others,” said Professor Peter Godfrey-Smith, lead author of the research. “Only a minority of cases appear to be targeted. I’d speculate that a lot of the targeted throws are more like an attempt to establish some ‘personal space,’ but this is a speculation, it’s very hard to know what their goals might be.”
While there are still questions to answer as to why the octopuses like to throw things at targets, the study establishes them as one of only a few animals known to do so, alongside primates, elephants, mongooses and birds. But the octopuses don’t “throw” in the same way humans do. They do gather and guide the materials using their arms, but the propulsion is driven by water jets expelled through their siphons.
Interestingly, the scientists found that females were generally more likely to throw things than the males, and there appears to be a relationship between the color of the creatures and their throwing behavior. This aligns with previous research linking darker octopuses with higher levels of aggression.
“Octopuses that displayed uniform color (dark or medium) threw significantly more often with high vigor, while those displaying a ‘pale and dark eyes’ pattern threw more often with low vigor," said Godfrey-Smith. “Throws by octopuses displaying uniform body patterns (especially uniform dark patterns) hit other octopuses significantly more often than in other body patterns.”
The research was published in the journal PLOS ONE, while you can see the octopuses do their thing in the video below.
Source: University of Sydney