When other cephalopods intrude on their personal space, they aren't exactly neighborly, even if it means turning things into weapons.
In a recently published study by a team of researchers in Australia, the US, and Canada, observations of wild octopuses casting shells and sand at other members of their species have raised questions over whether this unusual behavior is a deliberately antisocial act.
Scientists first observed a scene of heated argy-bargy off the eastern coast of Australia in 2015, where a large number of Sydney octopuses congregated.
They have determined in a new study that the flingers are mostly female and that they are trying to ward off overly amorous males.
At our two study sites, the throwing of material by wild octopuses is common. The throws are accomplished by gathering material and holding it in the arms.
There were 90 throws by women and 11 by men.
There are many reasons for animals to throw debris at one another. It can be either a threat or defensive behavior. Animals are throwing things at other animals, not their own.
A group of researchers led by a philosopher of science set out to observe the throwing of shells, silt, and algae.
They recorded over 100 instances of the inhabitants of Octopolis throwing debris. In order to blow up the material up to several body-lengths away, the octopuses would hold it in their arms, and then use their sucks to blast a jet of water that would blow the material up to several body-lengths away.
The researchers found that there were two main types of throwing. Keeping their dens free of debris and food waste was the first thing that needed to be done.
The second appeared to be more focused. The octopuses were observed throwing material at other octopuses. Shells were the most common object thrown.
silt was the best material for hitting the intended target for 33 percent of the throws. Other females or males were the targets.
In the year 2016 a female octopus threw material at a male 10 times over a period of 3 hours and 40 minutes. The octopuses that were hit did not try to retaliate, but did try to duck.
There is a slightly more controversial explanation for this behavior, which is that the throws are not always targeted, but could be a form of anger.
The researchers observed that one octopus threw things in a way that didn't seem to be directed at the other. It is not possible to conclude that this is the case given how difficult it is to assign intent to animals.
The throwing seems to play a role in the community.
"Octopuses can be added to the short list of animals who frequently throw or propel objects, and to the short list of animals who direct their throws on other animals," the researchers wrote.
The most common form of nonhuman throwing is directed at individuals of the same population.
The research was published in a peer reviewed journal.
The earlier version of this article was published in August of 2021.
All Rights Reserved © 2024
