A wild bottlenose dolphin on Australia's southern Great Barrier Reef has found a way to get a meal without catching it. He chases a fish until it throws up, then eats the vomit. The dolphin, nicknamed Bubbles, was recorded foraging on bigeye trevally 20 times between June 2021 and October 2025, and 11 of those chases ended with him eating the fish's regurgitated food. Researchers described the behavior in a peer-reviewed study of Bubbles published in Ecology and Evolution in mid-September.

The behavior is gross, but it is also rare science. Stealing food caught or collected by another animal is called kleptoparasitism. It is common in many animals but has rarely been documented in aquatic species, particularly marine mammals, according to the University of the Sunshine Coast's news release. The university describes the study as the first detailed description of kleptoparasitism in a cetacean, the group that includes whales, dolphins and porpoises. Scientific American called it some of the most compelling evidence of the behavior in the group.

The reason it stands out is repetition. One odd sighting could be chance. The same dolphin doing the same thing across several years looks like a tactic.

How Bubbles Turns a Fish's Meal into His Own

The routine follows a clear sequence. Bubbles approaches a school of bigeye trevally and searches for a specific target. He then singles out one fish, isolates it from the school and chases it. Eventually the stressed fish expels what it has recently eaten, and Bubbles snaps up the remains while the trevally swims away.

He rarely stops at one. Scientific American reported that he generally repeats the routine several times in a single session, performing up to 10 chases in 30 minutes.

People on the island had noticed him before the study. Marine biologist Jacinta Shackleton described the tactic bluntly to BBC Wildlife's Discover Wildlife: "He basically chases this one fish. The fish throws up. He eats the vomit." The study's lead author, Romney Edwards-Francis, a PhD candidate at the University of the Sunshine Coast, first saw it while snorkeling for the university's Leaf to Reef monitoring project. Master reef guide Pieter Demmers and Shackleton had already told her what Bubbles was known for.

Nature offers a close parallel. Frigatebirds chase feeding seabirds such as white-capped noddies through the air until the victims throw up their fish, and then the frigatebirds pluck the meal from the water's surface. Researchers think Bubbles is running a similar play underwater.

The Echolocation Idea, and Why It Is Still a Hypothesis

The most intriguing part of the study is also the least settled. During hunts, Bubbles makes intense, repeated clicks and low-pitched vocalizations. The researchers hypothesize that these sounds may heighten the fish's stress, and that echolocation may help him judge which fish has the fullest stomach before the chase begins.

The biology makes that plausible. "Echolocation does allow dolphins to discriminate small differences in their targets' shape, size and structure," study co-author Asia Haines told Scientific American, adding that more investigation is needed to confirm the idea. In the university's release, Haines said the repeated behavior "suggests he may have learnt to target the fish with the fullest bellies."

That idea has not been tested. According to reporting on the paper, the sound recordings came from a single encounter, and the researchers treat their interpretation as a hypothesis.

An outside expert urged caution on motive. Jason Bruck, a dolphin behavioral scientist at Stephen F. Austin State University in Texas who was not involved in the research, told Scientific American that seeing the same dolphin repeat the behavior makes it compelling evidence of more than opportunistic feeding. "I would be cautious, though, about assigning intention," he said. "We can't yet say the dolphin is pursuing the fish because it expects it to regurgitate."

The evidence has other limits. The study is observational and peer-reviewed, based on 20 recorded encounters with one dolphin at one site, documented by researchers and divers rather than a controlled survey. It did not measure how much energy the tactic saves. Edwards-Francis told Discover Wildlife that she suspects the vomit is an easy snack on days when Bubbles has not hunted as successfully, and the researchers think he probably still catches most of his own food.

A Reef Mystery That Could Be More Common Than It Looks

It is not clear how Bubbles learned the trick. He may have worked it out alone or picked it up from other dolphins. The researchers noted that common bottlenose dolphins tend to forage in groups, yet Bubbles was always observed foraging alone during these events.

Researchers suspect behaviors like this are underreported. "It's very possible that other individuals also use this tactic," Edwards-Francis told Discover Wildlife. "These behaviours are really difficult to observe under the water, and you have to be in the right place at the right time to capture it." The university team said pairing drones with underwater surveys could help catch more of these rare foraging tactics.

The setting helps explain why this case was caught at all. Lady Elliot Island lies in the southern Great Barrier Reef, and the bigeye trevally school is found in about the same location nearly every day, according to Edwards-Francis. The monitoring project is supported by the Great Barrier Reef Foundation's Reef Islands Initiative.

The find also shows how much wildlife science now depends on people who are simply in the water often. Reef guides and divers helped build this record. Bottlenose dolphins also live along U.S. coasts, from Florida and the Gulf to Southern California. Divers and boaters who film unusual dolphin behavior can share it with local marine mammal researchers or stranding networks, as long as they keep a legal distance.

Under the Marine Mammal Protection Act, it is illegal in U.S. waters to feed or harass wild dolphins. NOAA's marine life viewing guidelines for dolphins recommend staying at least 50 yards away. Anyone who sees a dolphin in distress should contact the regional stranding network rather than approaching it.

The bottom line: Bubbles has shown, again and again on camera, that a dolphin can profit by stressing fish into giving up their meals. Scientists do not yet know whether he picks the fullest fish on purpose, or whether other dolphins do the same. The research team has asked scientists worldwide to report similar sightings, and more footage could answer both questions.

What Readers Want to Know

What does Bubbles the dolphin do?

He chases individual bigeye trevally until the stressed fish regurgitate their food, then he eats the regurgitated meal.

How often was the behavior recorded?

The study includes 20 records of Bubbles foraging this way between June 2021 and October 2025, and 11 of them ended with Bubbles eating the vomit.

What is kleptoparasitism?

It means stealing food that another animal has caught or collected. Frigatebirds and many other species do it, but it has rarely been documented in marine mammals.

Does Bubbles use echolocation to choose his target?

Researchers think he might use echolocation to find the fish with the fullest stomachs. The idea is a hypothesis that has not been tested.

Where did this happen?

It happened off Lady Elliot Island in Australia's southern Great Barrier Reef.

Do other dolphins do this?

None have been documented doing it so far. Researchers say the behavior may be underreported because it is hard to observe underwater.

Can I approach dolphins to film behavior like this?

In U.S. waters, federal law prohibits feeding or harassing wild dolphins, and NOAA recommends staying at least 50 yards away. Share footage with local marine mammal researchers instead.