It's the sort of mystery that leaves ecologists hungry for answers: A submerged crab trap inexplicably hauled out of the depths, ripped open and the bait trap emptied – a few teeth marks the only clue that some sort of predator may be to blame.
It took almost a year and a set of remote cameras for researchers working on a wild stretch for coastline in British Columbia in Canada to identify the culprit: a wily sea wolf. The cunning canid was caught on camera in May last year wading into the depths, tugging on a buoy to which a crab trap was attached and yanking the entire contraption to the shore where it purposefully pulled it open and gobbled up the bait concealed in a cup within the trap. Ecologist Kyle Artelle, who published these findings in the scientific journal Ecology and Evolution alongside co-author Paul Paquet, described it as “highly efficient and focused behaviour.”
The crab traps had been set by members of the Haíɫzaqv (Heiltsuk) Nation to control invasive European green crabs, a ruthless crustacean that was introduced in California three decades ago and has since been steadily moving northward leaving a trail of destruction in its wake. To fight the crab scourge, the Haíɫzaqv Guardians have been placing specifically designed traps in the shallow intertidal zones as well as in deeper water, where they use coloured floats to mark their locations. Floats, it appears, that wolves have learnt to identify.
"We figured wolves or bears were getting to these traps because the traps were fairly accessible during low tide,” Artelle told The Guardian. “But we just couldn’t figure out what was attacking the deeper traps." The team initially suspected otters or seals, but it was only when they pointed a remote camera at one of the crab traps that the thief was revealed.
“We couldn’t believe our eyes. It was serendipity that we actually captured this behaviour. And it was, quite simply, inspiring,” said Artelle. Sea wolves are a subspecies found on coastal islands that mostly feed off marine prey like salmon, shellfish and seals. These canines (and others like them) have long been considered intelligent, but evidence of this has not been extensively documented in wild wolves. "This isn’t genetic," Artelle adds. "This is an entirely learned behaviour, and learned very fast, and likely shared among the group.”
The scientific community is divided on whether the recorded behaviour constitutes tool-use, with some arguing that the 'tool' in this case was not created or manipulated by the wolf. As such, this represents a case of object use, not tool use. It's unclear exactly how the wolf learned this behaviour, but it's possible it witnessed humans setting and retrieving traps or it first encountered traps that were only semi-submerged and after discovering the bait cups, learnt to associate the traps and their colourful buoys with food.
What is clear, however, is that this wolf is the goodest boy. And its learned behaviour points to a species with advanced problem-solving skills and intelligence.
Header image: Katmai National Park and Preserve
Natural World
Animal Behaviour
Animal Behaviour
