Over the last decades, whale and dolphin populations around the world have dwindled significantly as a result of human activities. And while conservationists are working hard to help these animals recover, collecting data about their health in a non-invasive way can be extremely difficult.
To better understand how people influence the overall health of dolphins, a team of researchers at Oklahoma State University are developing a drone to collect samples from the spray that comes from their blowholes. Using these samples, the scientists hope to learn more about these animals’ health, which can aid in their conservation.
Today, researchers wanting to measure wild dolphins’ health primarily use a small dart to collect a sample of tissue or handle the animals in order to collect samples. These methods don’t physically harm the animals, but despite precautions, they can be disruptive and stressful for dolphins.
In a bid to come up with a better sampling method, the research team is building a drone that would fly into a dolphin’s blind spot and collect samples from the mucus that is mixed with water and air sprayed out of a dolphin’s blowhole when they exhale a breath – also called the ‘blow’.
When sampling the blow, the scientists are looking for hormones in mucus as these can be used to gauge psychological and physiological health. For instance, hormones like cortisol and progesterone indicate stress levels and reproductive ability respectively, but can also help determine overall health.
Currently, the researchers are collaborating with trained dolphins to build a drone that can stealthily collect spray from their blows. Particularly, they are interested in acquiring more data on their eyesight and hearing, which can’t be collected in the wild nor simulated in a lab. This is where it gets really interesting!
To test dolphin hearing, they set up microphones and cameras to record dolphin behavior as they played drone noise in the air. They analyzed the responses to each noise – such as how many dolphins looked at the speaker – and used these as a proxy for their ability to hear the sounds.
As for testing vision, the researchers mounted lights inside an expandable plastic sphere that they could turn on and off. The dolphins were trained to whistle when they saw a light around their head. By turning on one light at a time – which you can watch in this video – they created a map of the dolphin’s field of view.
In the next few months, the researchers will test flights over a robot dolphin they have also built to determine the timing and strategy for collection. From there, they will fabricate a low-noise drone that can fly fast enough and with sufficient maneuverability to capture samples from wild dolphins.
If all goes well, in a few years the technology would be a major contribution to conservation efforts, allowing researchers to do better science in a stress-free and non-invasive way.
