- Scientists in Indonesia have tagged a pygmy blue whale for the first time using a drone.
- Data from the tag revealed a previously unknown path used by the species on its southern migration from Indonesia to the west coast of Australia.
- The biggest threats to the pygmy blue whale include ship strikes in busy shipping lanes, ocean noise pollution, and climate change.
- A team from Timor-Leste will now repeat the drone tagging protocol in their waters.
Indonesian scientists have attached a satellite tag onto an endangered pygmy blue whales for the first time by drone.
The tag’s data not only revealed a new feeding site for the species (Balaenoptera musculus brevicauda), but also a previously undocumented path it takes to the South Antarctic.
Unlike Antarctic blue whales, pygmy blue whales prefer tropical waters and are found in the Indian Ocean. They’re known to migrate between the west coast of Australia and Indonesia. However, their journey south between Indonesia and Australia is rarely documented and their habits are more of a mystery.
From Oct. 5-16, 2025, a team of 20 scientists from Konservasi International, Thrive Conservation, the Elasmobranch Institute and universities from Indonesia and Timor-Leste focused their research on the Lesser Sunda landscape, which is part of the Coral Triangle. The study area also includes the Ombai Strait, known as one of the most important migratory corridors for pygmy blue whales.
In December 2025, Indonesia created the new 325,238 hectare West Wetar Marine Protected Area, found within the Lesser Sunda seascape, the scattering of Indonesian islands closest to Australia. During the expedition, the team also gathered data to help the government create an offshore marine protected area in the Banda Sea.
The pygmy blue whale’s biggest threats include ship strikes in busy shipping lanes, ocean noise pollution, and a rise in sea temperatures.
The rare pygmy blue whale has been tagged before, but never by drone. Previously, researchers used carbon fiber poles or air guns to affix tags, which meant having to use small boats to get within 10 meters (33 feet) of the whale. By using a drone, they can tag the whale from up to 300 m (nearly 1,000 ft) away and minimize disturbance to the animal. (Drone tagging has previously been successfully used on other marine mammals, including humpback and sperm whales.)
The team used what’s known as a limpet tag, which is light enough for the drone to carry, and has minimal effect on the animal. The tag attaches with two small barbs onto the skin, which one expert said was similar to a bee sting. Once attached, the limpet tag is able to measure depth, position and water temperature.
Timing is key, said oceanologist Mochamad Iqbal Herwata of Konservasi Indonesia: “After the blow, we have a two-second chance to release the trigger [before] the whale goes below the water.”
Each tag can cost around $5,500 and the team only had four to work with, so they first practiced piloting the drone on dry land, dropping the tag into a box placed in the middle of a soccer field.
A rough start
For the first two days of the expedition, the team didn’t see any whales. “We saw plenty of sea birds,” Herwata said. By Oct. 12, their luck changed, and they were in the presence of pygmy blue whales for six hours.
With only 20 minutes of battery life on the drone, the team needed to move quickly and work precisely.
They needed to attach the limpet tag in the “flatter space” behind the whale’s blow hole and in front of its fins, while contending with the wind and the movement of the whale itself.
None of the shots the team made that day hit their mark. After each attempt, they had to collect the tag from the water, reset, and go again. “It is very stressful. Renting the boat is expensive, the tags are very expensive, so there’s a lot of pressure proving the concept,” Herwata said.
Finally, after nine failed attempts, the researchers managed to tag a pygmy blue whale on Oct. 13. Data from the tag went on to show that the whale traveled through shipping lanes and seaweed cultivation zones.
“Landing the tag was an unforgettable moment,” Herwata said. “These insights are already helping us understand how pygmy blue whales move through the Lesser Sunda Seascape and how we can better protect them.”
Cetologist Putu Liza Mustika, a lecturer at James Cook University in Australia, joined the expedition. She had previously carried out an expedition studying pygmy blue whales in November 2021, but had used a tracker that was attached by air gun, so she was interested to see how the drone worked. “The drone is much less intrusive than [the] air gun,” Mustika said.
However, as the tag is dropped by a drone, it doesn’t attach quite as firmly as one fired into the blubber from an air gun, and thus detaches sooner. “It’s still quite difficult to have a full attachment,” Mustika said. “We only had 10 days of recording and then we lost the transmission.” A limpet tag deployed by air gun can stay in place for up to two months.
However, the data they recorded yielded more than they’d expected, including the discovery of a new whale corridor and a new feeding site. In all, the tagging attempt uncovered more than 2,000 kilometers (1,200 miles) of the whale’s journey, providing new data on the endangered species’ migrations.
An interactive map from Konservasi Indonesia shows the path of the tagged whale.
“We thought that they entered the Savu Sea [in the Lesser Sunda Islands, then went] warp speed [to Australia],” Mustika said. But “they are really just hanging around.”
Ecologist Michele Thums from the Australian Institute of Marine Science, who wasn’t part of this project, has been studying pygmy blue whales for six years. Having used air guns to attach tags, she said she wants to move to the drone method because it’s less stressful to the animal than to approach it by boat: “We’re really ecstatic they had success, and that we’ve all learned something about putting these tags on with drones. What we all want to do [is] to reduce stress on the animals and to improve our chances of getting the tags on.”
Robert Harcourt, facility leader of IMOS Animal Tracking at the Sydney Institute for Marine Science & School of Natural Sciences, Macquarie University, who wasn’t involved with the project agreed that conventional tagging methods can always be improved. “Whales in particular are most disturbed by close approaches by boats,” Harcourt said. “Traditionally we have used crossbow or modified rifles to tag whales. This involves a degree of risk to both whales and researchers.”
He added, “It’s clear that the technology to tag short-term suction cup tags from drones is effective. However, long-term tagging [with] implanted tags from drones is still in early development. [But], I am confident that within a few years [drones] will be the default method.”
The program is about to be expanded to other countries as scientists from Timor-Leste joined the expedition to also learn the process so they can apply the drone tagging in their waters later this year.
Drone surveys offer early warnings on whale health and survival
Credits
This story first appeared on Mongabay
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