A dolphin on the Great Barrier Reef has developed a remarkable method for obtaining food without capturing its prey itself.
The animal is a male bottlenose dolphin regularly observed near Lady Elliot Island, Australia. Researchers and local regulars know him by the nickname Bubbles. Between June 2021 and October 2025, they documented 20 encounters during which he showed interest in schools of bigeye trevally.
Bubbles, the bottlenose dolphin observed near Lady Elliot Island, swims among trevally on the reef.
Credit: Mary Porter / Great Barrier Reef Foundation.
Eleven of these observations ended in the same way. The dolphin chased a trevally until it expelled the food it had just swallowed. Bubbles then retrieved the meal and allowed the fish to swim away. The videos never showed the dolphin eating the trevally directly.
To understand the appeal of this strategy, we need to look at the behavior of these fish. Trevally gather in schools in this part of the reef, making them a predictable resource. When heavily pursued, they can expel what they have recently swallowed. Bubbles appears to have learned to exploit this reaction precisely.
This behavior has a name: kleptoparasitism. It involves an animal stealing food obtained by another. The practice is known in many species, particularly birds. Among marine mammals, possible cases had already been reported, but researchers had not observed the attackers subsequently swallowing the expelled food.
The researchers confirmed that it was always the same dolphin by examining markings on its dorsal fin and a V-shaped scar. During its pursuits, the animal also produces rapid bursts of echolocation clicks and low-frequency sounds. However, the available data do not make it possible to claim that these sounds themselves trigger the food expulsion.
Bubbles targets a bigeye trevally in the school, chases it, then retrieves the food it regurgitates.
Credit: Michael Ingram, Edwards-Francis et al., Ecology and Evolution (2026).
One might think this was simply an opportunity seized by chance. Yet the repetition of the same sequence over several years points to a learned behavior. The dolphin has frequented this part of the island since at least 2017. According to local observations reported in the study, it regularly repeats this tactic for several days in a row.
What remains to be determined is what Bubbles actually gains from it. The authors suggest that stealing an already captured prey item could require less energy than hunting alone. Other dolphins will also need to be observed to determine whether this technique remains an individual specialty or can be learned and passed on to companions.