In a remarkable demonstration of cetacean intelligence and cultural transmission, a growing number of orcas around the Iberian Peninsula have been engaging in what scientists and sailors describe as “coordinated attacks” on vessels. These killer whales, magnificent apex predators of the ocean, appear to be teaching each other techniques to interact with—and sometimes disable—boats passing through their territories. This phenomenon, which began in 2020, has evolved from curious interactions to increasingly sophisticated behaviors that suggest intentional knowledge-sharing within orca pods. As these majestic marine mammals adapt to human presence in their domain, we’re witnessing an extraordinary example of behavioral evolution and social learning that challenges our understanding of these complex creatures.
The Emergence of a New Orca Behavior
The first documented incidents of orcas deliberately targeting boats occurred in the Strait of Gibraltar in May 2020. Initially, sailors reported isolated encounters with orcas bumping into rudders and occasionally spinning vessels. Marine biologists were puzzled by this new behavior, which seemed to appear suddenly and spread rapidly among the local orca population. Prior to 2020, such interactions were extremely rare and usually involved juvenile orcas exhibiting playful curiosity rather than the more intentional contact observed in recent years.
What began as occasional interactions has escalated to over 500 documented incidents in the waters between Spain, Portugal, and Morocco. Scientists have noted that the behavior appears to be spreading through cultural transmission—the passing of knowledge from experienced individuals to others in their social group. This represents a remarkable example of social learning in a non-human species, demonstrating the sophisticated cognitive abilities of these marine mammals.
Understanding Orca Intelligence
Orcas, or killer whales (Orcinus orca), possess some of the largest brains in the animal kingdom relative to their body size. Their brains feature an expanded limbic system and highly developed neocortex—areas associated with complex thinking, problem-solving, and emotional processing. Research has consistently shown that orcas display remarkable intelligence, with cognitive abilities comparable to those of great apes and elephants.
This intelligence manifests in numerous ways, including the use of sophisticated hunting strategies, development of distinct dialects within pods, and the ability to recognize themselves in mirrors (indicating self-awareness). The complex social structures of orca pods provide an ideal environment for the transfer of knowledge across generations. Their capacity for cultural transmission is well-documented, with different pods developing unique hunting techniques and behaviors that are taught to younger members through observation and practice.
The Mechanics of Boat Interactions
The boat interactions follow a surprisingly consistent pattern. Typically, orcas approach vessels from behind, focusing their attention on the rudder. They use their bodies to push against the rudder, sometimes with enough force to turn the vessel or bring it to a complete stop. In more intense encounters, the orcas will repeatedly ram the rudder until it breaks, effectively disabling the boat’s steering capability.
Scientists analyzing footage have observed that the orcas appear to be intentionally targeting the rudder rather than randomly bumping into boats. They often work in coordinated groups of 2-5 individuals, taking turns to push against the vessel. The force exerted can be substantial—enough to spin a 45-foot yacht in circles or break rudders constructed from reinforced materials. Some sailors report feeling as though they were “being played with” during these encounters, as the orcas would retreat briefly before returning for another pass at the vessel.
The Iberian Orca Population
The orcas involved in these incidents belong to a specific endangered subpopulation known as the Iberian or Southern population. Numbering only about 39 individuals, these orcas are genetically distinct from other Atlantic orca populations. They primarily feed on bluefin tuna and follow the tuna’s migratory patterns through the Strait of Gibraltar between the Atlantic Ocean and Mediterranean Sea.
This population faces significant threats from overfishing, which has depleted their primary food source, as well as pollution and habitat degradation. Researchers have identified several individual orcas repeatedly involved in boat interactions, including a female named “White Gladis” who is believed by some scientists to be the originator of the behavior. Several hypotheses suggest she may have had a traumatic encounter with a vessel in the past, potentially triggering a behavioral change that has spread throughout her social group.
The Social Learning Hypothesis
The rapid spread of this boat-interaction behavior provides compelling evidence for social learning among orcas. Researchers from the Atlantic Orca Working Group have documented how the behavior appears to be transmitted from more experienced individuals to younger pod members. Initial encounters typically involved adult orcas, but subsequent interactions increasingly included juveniles who appeared to be observing and mimicking the techniques of their elders.
This pattern is consistent with what scientists call “cultural transmission”—the non-genetic transfer of behavior through social learning. Similar phenomena have been documented in other orca populations, such as the specialized hunting techniques used by Antarctic orcas to create waves that wash seals off ice floes. The boat interaction behavior represents a particularly dramatic example of such transmission, as it involves a novel behavior that appears to have emerged recently and spread rapidly through the population.
Possible Motivations Behind the Behavior
Scientists remain divided on what might be motivating these interactions. Several theories have emerged to explain the phenomenon. One hypothesis suggests that the behavior may have originated as a form of play that has been reinforced through social learning. Orcas are known to engage in complex play behaviors, and the physical sensation of pushing against a rudder might be inherently rewarding, similar to how domesticated dogs enjoy tug-of-war games.
Another theory proposes that the behavior represents a form of retaliation or defensive response to negative experiences with vessels. Fishing boats in the region use long lines that compete directly with orcas for bluefin tuna, and there have been documented cases of orcas being injured by fishing gear or boat propellers. Some researchers speculate that an individual orca may have had a traumatic encounter with a vessel, leading to aggressive or defensive behavior that was subsequently learned by others in the pod. However, there’s little concrete evidence supporting this “revenge” hypothesis, and anthropomorphizing animal behavior can lead to misinterpretations of their motivations.
Documented Incidents and Their Escalation
The frequency and intensity of these interactions have increased significantly since they were first documented. In 2020, approximately 52 incidents were reported. By 2022, that number had climbed to over 200, and 2023 has already seen more than 300 reported interactions. More concerning is the apparent escalation in the severity of these encounters. Earlier incidents typically involved brief contacts with the rudder, whereas more recent reports describe prolonged interactions lasting up to two hours and resulting in significant damage to vessels.
In July 2023, a particularly severe incident resulted in the sinking of a yacht off the coast of Portugal. The vessel Alboran Cognac was struck repeatedly by a group of orcas that damaged the rudder beyond repair, causing water to flood the boat. The crew was rescued, but the yacht sank—marking the first total loss of a vessel attributed to orca interaction. Several other vessels have required emergency assistance and towing to port after sustaining damage to their steering systems. Maritime authorities have established protocols for handling these incidents, including emergency response procedures and temporary sailing restrictions in areas with high orca activity.
The Human Response
As incidents have increased, maritime authorities in Spain and Portugal have implemented various measures to reduce risks to both vessels and orcas. The Spanish Transport Ministry has periodically designated “exclusion zones” where sailboats under 15 meters are temporarily prohibited from traveling. These restrictions aim to reduce the opportunity for interactions while researchers work to better understand the behavior.
Sailors transiting the affected areas are advised to follow specific guidelines if orcas approach: stop the vessel, lower sails, turn off the engine, retract any fishing lines, and avoid physical contact with the animals. Authorities emphasize that orcas are protected species, and harming them is illegal under international conservation laws. Some boat owners have resorted to installing reinforced rudders or rudder protection devices, while others use deterrent methods such as playing specific underwater sounds believed to discourage orca approaches.
Scientific Research Efforts
The scientific community has mobilized to study this unprecedented behavioral phenomenon. The Atlantic Orca Working Group, a collaboration of marine biologists from Spain, Portugal, and other European countries, is leading research efforts. They are collecting data on each interaction, including photographs to identify individual orcas involved, duration of encounters, and any patterns in timing or location.
Researchers are employing various technologies to monitor the orcas, including underwater acoustics to record their vocalizations during boat interactions, drone footage to observe their behavior from above, and satellite tracking of known individuals. Some scientists are exploring whether the interactions might be influenced by environmental factors such as changes in prey availability, water temperature, or acoustic pollution. Others are focusing on the social dynamics within pods, attempting to map how the behavior spreads between individuals and groups. This research not only helps understand the immediate phenomenon but contributes to broader knowledge about cetacean cognition and cultural transmission.
Conservation Implications
The boat interaction behavior has significant conservation implications for this endangered orca population. While the behavior itself poses risks to the animals—including potential injuries from boat propellers or retaliation from frightened sailors—it has also drawn unprecedented attention to their conservation status. The Iberian orca population faces numerous threats, including prey depletion, pollution, underwater noise, and habitat degradation.
Some conservation biologists suggest that the behavior might indirectly benefit the orcas by raising awareness about their precarious situation and generating public support for stronger protection measures. Others worry that negative publicity could erode public sympathy for the species. Conservation organizations are working to use the increased attention to advocate for stricter fishing quotas for bluefin tuna, expanded marine protected areas, and reduced ocean pollution in the region.
Similar Behaviors in Other Marine Mammals
While the systematic targeting of boat rudders appears to be unique to the Iberian orca population, other cetaceans have demonstrated behaviors that suggest cultural transmission of boat interactions. Dolphins in various locations have learned to follow fishing vessels to feed on discarded catch or fish stirred up by nets. In Australia’s Shark Bay, bottlenose dolphins have developed the skill of using sponges as tools to protect their snouts while foraging on the seabed—a behavior that is taught from mother to offspring.
Humpback whales provide another striking example of cultural transmission, with populations developing distinct “songs” that evolve over time and spread between groups. However, the Iberian orca behavior represents a particularly rapid and potentially consequential form of cultural transmission that directly impacts human activities. Some researchers suggest that as human presence in the oceans increases, we may see more examples of marine mammals adapting their behavior in response to our activities, potentially including learned behaviors that are transmitted culturally within their social groups.
Conclusion: The Evolving Relationship Between Humans and Orcas
The phenomenon of orcas teaching each other to interact with boats represents a fascinating intersection of animal behavior, conservation, and human-wildlife conflict. It demonstrates the remarkable intelligence and social complexity of these apex predators while raising important questions about our relationship with the marine environment. As we continue to share ocean spaces with these sophisticated beings, we must balance our activities with respect for their natural behaviors and habitat needs.
The ongoing research into this behavior provides valuable insights not just into orca cognition, but into the broader capacity of animals to adapt to human presence through cultural learning. While the immediate concern focuses on preventing damage to vessels and ensuring human safety, the longer-term implications may help reshape our understanding of cetacean intelligence and the need for conservation approaches that account for their complex social structures.
For sailors and marine enthusiasts, these events serve as a humbling reminder that we navigate through territories that belong primarily to wild creatures with their own societies, cultures, and behaviors. As we move forward, finding ways to coexist peacefully with these magnificent marine predators will require continued scientific study, adaptive management strategies, and a deeper appreciation for the intelligence and agency of the animals with whom we share our blue planet.
Whether the orcas’ behavior represents play, retaliation, or something else entirely may remain partially mysterious, but what’s clear is that it demonstrates their capacity for sophisticated learning and cultural transmission—reminding us that in many ways, these remarkable animals are far more like us than we previously understood.
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