Orcas have struck again in Spain! On October 31st, Polish tourists experienced a Halloween nightmare when a group of cetaceans attacked their yacht’s rudder for 45 minutes, eventually causing the boat to sink. Fortunately, the crew members were unharmed. This incident adds to a growing list of similar events reported since 2020, with over 500 interactions recorded with ships, especially sailboats, off the coast of Gibraltar. The modus operandi typically remains the same: a group of cetaceans approaches a boat, pushes it for extended periods, and sometimes bites parts of the vessel. So far, no fatalities or injuries have occurred, but the imagery is certainly unsettling.
One favored media theory to explain this phenomenon is vengeance against human activities that harm marine environments. Some even speculate that these behaviors indicate an evolution of orca intelligence.
Understanding Orca-Ship Interactions
Before addressing this question, it’s essential to understand why these behaviors occur. Today, the prevailing hypothesis is playfulness. Orcas have no reason to seek revenge for past actions. Their primary goals are hunting, reproduction, and having fun. Furthermore, if this habit is new, there are comparable precedents. In the early 2000s, some orcas played with fishing traps, found it amusing, and others imitated their behavior, but it eventually ceased.
Unfortunately, the new fascination of orcas is the rudder, a part of the ship’s steering system that they push and bite until it detaches. This doesn’t prevent them from continuing to play with it, far from the boat. If this game has spread beyond the Gulf of Gibraltar, it’s simply because learning is an integral part of orca behavior, as they imitate their peers. They are not inherently aggressive. However, the consequences of their pastime are serious, as it can lead to shipwrecks and long-lasting trauma for those on board.
Measuring Intelligence: A Complex Question
If it’s a game, not revenge, is it still relevant to question the evolution of the intelligence of this species? First, it’s important to note that the concept of animal intelligence should be approached with caution. We must consider whether the animal can solve problems, what types of problems, and its adaptation to change. It’s a very complicated question for scientists. Animal intelligence can take many forms, varying from one species to another, and its evaluation is often influenced by human biases.
One tool used today to measure it is the encephalization quotient, which is the relative measure of brain size compared to an animal’s body size, typically a mammal. The higher this quotient, the larger the brain is in proportion to body size. Species with a large brain are generally considered to have a higher level of cognition than expected. For example, humans have an encephalization quotient of 7.7, the highest known, while dogs range from 1.4 to 1.7. What about Orcas? With an encephalization quotient of 2.57, they are known for their high intelligence.
Is Orca Intelligence Evolving?
Does this measure adequately capture the complexity of their behaviors? It’s far from certain. Their encephalization quotient, for example, falls short of the 4.4 of their cousin, the bottlenose dolphin. Yet, after humans, orcas are the most widely distributed species across the globe, as they have colonized all oceans. Moreover, each population of orcas exhibits different hunting behaviors depending on their habitat.
Since the rise of industrial fishing, populations have adapted. In just two decades, most orcas worldwide have adopted the technique of “depredation,” following boats to retrieve prey caught in nets and hooks. These techniques are not without danger, as some (usually illegal) fishermen equip themselves with explosives to fend off orcas.
The intelligence of these mammals continues to fascinate, and if it is evolving, it’s impossible to determine.
In conclusion, there’s no need to panic. Scientists are not concerned, except for the negative portrayal of orcas in the media. It’s essential to remember that these cetaceans are not predators of humans!