Dolphin Bubbles Exhibits Unusual Kleptoparasitic Behavior

A bottlenose dolphin named Bubbles has been observed engaging in a peculiar foraging behavior that involves inducing fish to vomit and then consuming the regurgitated food. This behavior, known as kleptoparasitism, has been documented by researchers at the Lady Elliott Island Eco Resort, located off the southern Great Barrier Reef in Australia.

Bubbles has been a familiar presence at the resort since at least 2017, and his unusual feeding strategy has now become the subject of a study published in the journal Ecology and Evolution. According to the study, Bubbles targets bigeye trevally, chasing them until they regurgitate their stomach contents, which he then eats. This behavior challenges the common perception of dolphins as friendly and non-predatory creatures.

Asia Haines, a co-author of the study from the University of the Sunshine Coast, explained that the perception of dolphins as the "good guys of the sea" is largely due to anthropomorphism. "Dolphins are predators and actively hunt their prey, whether it has been stolen from another species or not," Haines stated.

Kleptoparasitism typically involves one species taking food from another, often through aggressive means. While this behavior is common among certain terrestrial animals, such as bears, coyotes, and wolves, it is rare among marine mammals. However, there have been reports of Risso’s dolphins exhibiting similar behavior with sperm whales.

Between June 2021 and October 2025, researchers documented 20 foraging sightings of Bubbles, with 11 involving kleptoparasitic behavior. Bubbles employs echolocation to identify a suitable target fish, then chases it until it vomits from stress. The dolphin then consumes the regurgitated food, allowing the fish to escape. This process can be repeated up to 10 times in a half-hour session.

Interestingly, Bubbles does not consume the fish itself, focusing solely on the regurgitated contents. While dolphins typically forage in groups, Bubbles often hunts alone, suggesting that this behavior may be a learned strategy that requires less energy compared to traditional hunting methods.

The study of Bubbles's behavior provides insight into the complex and adaptive foraging strategies of dolphins, highlighting their predatory nature and challenging the simplistic view of them as merely playful and benign sea creatures. This behavior is particularly intriguing because it deviates from the more common group foraging tactics seen in dolphins. Bubbles's solitary hunting method may offer advantages in terms of energy conservation and efficiency, as it allows him to exploit a niche food source without competition from other dolphins.

The implications of this study extend beyond understanding dolphin behavior. It prompts a reevaluation of how marine mammals adapt to their environments and how these adaptations can lead to unique survival strategies. As researchers continue to observe Bubbles, they hope to uncover more about the cognitive and environmental factors that drive such innovative behaviors in marine life.

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