"There are scallops everywhere, providing an almost unlimited food source, while the mound of scallop shells provides an island of safety amidst a sea of predators including sharks, dolphins, seals and pack-hunting leatherjackets," Professor Godfrey-Smith said.
"Perhaps they are just tolerating each other; perhaps there's more engagement. [We know] they mate at the site as well."
During the 52 hours of footage collected, the octopuses interacted with each other 186 times, and engaged in a range of actions, from standing tall, to raising their mantle over their head, throwing debris at or poking each other, spreading their webs, or darkening their skin tone.
"When one octopus sees another dark-skinned octopus approaching, it may 'go dark', indicating that the encounter is likely to escalate," Professor Godfrey-Smith said.
Like other cephalopods, octopuses are able to change color and pattern by dilating or contracting chromatophores in their skin.
"They then stand tall with their web spread in what we call the Nosferatu pose, after the classic film vampire, with the encounter likely leading grappling or other acts of aggression," Professor Godfrey-Smith said.
When a dark octopus approaches a pale one, however, the pale animal usually retreats, while a dark octopus approached by one with more subdued colors is more likely to stand its ground.
"We don't know exactly why they engage in these heated exchanges. It could be an attempt by one or more animals to control territory, as we saw males excluding males but not females, but this isn't always the case," Professor Godfrey-Smith said.
Professor Godfrey-Smith and Professor Scheel enlisted the help of a group of students to analyse the video.
"They binge-watched 52 hours of GoPro footage of octopuses walking around and poking each other, scoring the octopuses' moods by measuring their pixels of their skin color against those in the background," Professor Godfrey-Smith said.
"It's harder than it sounds. Trying to keep track of who's who is very difficult. They can change color or shape in a second, and when one moves into view it is hard to tell whether they are a new animal -- or one that you've been watching for ages.
"We would love to know to what extent this behaviour was about males trying to control territory or whether it was part of a richer and more complicated social life that we are only just becoming aware of."