Imagine being able to help wildlife along with technology. How cool is that? And so is the fact that scientists use drones to ensure that seals are healthy. When science evaluates the well-being of wildlife, it usually comes right down to obtaining a few key measurements that represents the animal’s “body condition,” which includes taking their length and their weight. But to get this data can be not only labor intensive, it can also be invasive. This is particularly true when dealing with leopard seals, which are found in the frigid conditions of Antarctica. However, brand new research indicates that gathering measurements from these seals using aerial drone photos can as accurate as getting data with traditional methods – and it requires a lot less effort, time, and money too.
Supporting the Local Food Chain
Leopard seals are what is called an “indicator species,” which means that their overall health immediately tells scientists the status of the local food chain. This is because they are “apex predators,” and are either indirectly or directly dependent on each and every member of that local food web. These seals will hunt and prey on penguins, who in turn will hunt krill ( which are tiny, shrimp-like crustaceans). So whenever the krill have problems, these leopard seals will become affected by it, and that will become apparent by in the conditions of their bodies.
So in essence, these leopard seals are serving as the canary in the coal mine for this Antarctic ecosystem. But the seals are not exactly making it very easy. They can be very hard to find, and of course, their habitat is among one of the most inhospitable on Earth. And of course, the fact that these leopard seals typically weigh around 1,000 pounds, have very dangerous fangs, and have no interest in getting captured does not help the cause either. To obtain data in this manner requires sedation, which is a very risky option to not only the seals, but to the researchers as well.
So to eliminate any direct interaction between seals and humans would eliminate a great deal of stress from both parties. And this is exactly why this new study is so encouraging and exciting. Researchers have begun using images of seals collected by aerial vehicles that are unmanned (i.e. drones) to obtain the body measurements of the seals, and then this data was compared to measurements that were already know to evaluate the accuracy of the drone. This approach has been found to work very well and yield results that were quite accurate.
Researchers at the NOAA Fisheries’ Southwest Fisheries Science Center conducted this study on Livingston Island located in Antarctica—which is a very popular place for leopard seals, as they exist there in great numbers. It was there that they managed to capture 15 very healthy, adult female seals. They sedated these seals and then obtained critical measurements like their lengths and their girths. They were weighed using slings and hand winches. And afterwards, the seals were given sedative-reversal drugs to awaken them.
Shortly thereafter, the researchers employed a hexacopter UAV which had a mounted camera to capture images of the seals at various altitudes and also in different body positions. By using familiar features of the camera, the research team was able to calculate “photogrammetric” measurements from the seals strictly based on the images. And then after employing body mass estimation methods, they were able calculate the seals’ body mass indexes from the photos.
As it turned out, the drone method of measuring the seals was very accurate – within a few percent of the original measurements. So now the scientists use drones to ensure that seals are healthy.