The Trick to Studying Dolphins Without Stressing Them Out

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Ddolphins, whales, and other beloved marine mammals face myriad harms from human activities. Stresses from climate change, pollution and commercial fishing can lead to health problems, including injuries and disruption of the endocrine system, which can endanger the survival of a wider population. Largely due to humans, marine mammal communities are at high risk in nearly half of the world’s coastal waters.

Typically, researchers only notice these problems when a significant number of animals die at the same time or when a population has declined to such a level that conservation measures cannot help significantly. But it is difficult to monitor marine mammals because they are generally submerged and on the move. Checking their vital signs like body temperature and respiratory rate in the wild often involves hands-on techniques, such as rectal probes and heart tests called electrocardiograms, which can stress animals, provide unreliable measurements and tend to be expensive.

The good news: Drones can offer a non-invasive alternative. By attaching thermal cameras to drones, researchers can check an animal’s temperature and respiratory rate, both of which can indicate illness or injury. Such cameras have already been tested on terrestrial and marine animals, but few studies have verified whether these measurements correspond to those taken directly.

Seeking to strengthen this area of ​​research, a team of scientists based in Australia flew drones equipped with thermal cameras at different heights and measured the temperatures of the vents, bodies and dorsal fins of 14 adult bottlenose dolphins, as well as the respiratory rates. These are tracked by observing the temperature changes as air enters and exits the vent with each breath. To assess the accuracy of this technique, they compared the camera data with measurements taken near the dolphins with handheld infrared thermometers and directly with a rectal probe.

Read more: »To stop illegal fishing, send a seabird»

Over the course of two seasons, scientists captured more than 30,000 images of dolphins with a variety of heights and drone angles, as well as a mix of shots where the animals’ upper bodies were in and out of the water. They found that a drone height of around 32 feet worked best, for example, and that overall this monitoring method matched measurements taken at close range. They reported their results in the Journal of Thermal Biology.

The discovery of the dolphins comes with some caveats: for example, these dolphins were under human supervision at Sea World in Australia. It’s possible that wild dolphins react negatively to drones buzzing overhead, as has been found in previous studies, but reactions appear to vary depending on context. In future work, drone surveillance could be tailored to specific populations, the authors note in the paper.

“As coastal ecosystems face increasing pressure, tools such as thermal drones that allow researchers to monitor wildlife efficiently, repeatedly and non-invasively will become increasingly important,” wrote study authors Charlie White and Guido J. Parra of Flinders University. The conversation.

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Main image: C White/CEBEL (Flinders University)

• Molly Glick

  Published on January 9, 2026

  Molly Glick is the newsletter editor of Nautilus.