Understanding energy expenditure can help scientists understand how well animals are and whether they will be able to hunt, reproduce, and survive. To date, Wilson has used accelerometers to study all kinds of animals, including sea turtles, sheep, bats, hawks, and penguins. It combines data from the accelerometer with inputs from other sensors that measure temperature, magnetic force, and geolocation to understand exactly what the animal is doing and where it is. For example, technology allows him to follow penguins as they sit on their nests, get up, waddle to the ocean, and dive. His sensors can stay on animals for weeks, and after recovering the devices, Wilson can follow. as the penguins swim, dive and fish, all thousands of miles away.
He’s so good at reading data that he can even begin to understand the details of the physical condition of animals. He can tell when the penguins are full of fish, for example, because it changes the way they waddle. Or he can tell when a horse starts to walk over difficult terrain. “It’s really cool,” he says.
Like Chusyd, Wilson became familiar with how to attach accelerometers to animals and ensure the sensors will survive the data collection process. For penguins and other birds, it will insert a special ribbon under their back feathers, creating a small waterproof pocket in which it will enclose the device. He used magnetic and spring clips to attach sensors to shark fins. When he studied sheep urination, he cut small holes in the wool on the backs of the animals, stuck the sensors in their coats, and repacked the pockets with the tufts of shaved wool. For sloths, he used a harness, and for bats, he used rubber cement to secure accelerometers to their tough skin.
For Anthony Pagano, a postdoctoral researcher who works with the US Geological Survey, accelerometers have helped shed light on the activity of polar bears living in northern Alaska, providing information that may be nearly impossible for humans to observe. “We have a lot of detailed information on changes in body mass and survival rates, but we don’t have a lot of information on basic movement patterns and what their basic behaviors are on sea ice.” , he said.
These bears live in extreme and remote environments. Temperatures can drop from 40 degrees below zero to 30 degrees above zero. Polar bears dive in and out of freezing saltwater oceans, hanging out on ice and also walking on solid ground. Pagano eventually had to coat the accelerometers with epoxy to make them waterproof, mount them in an aluminum casing, and bolt the entire unit onto tracking collars around the bears’ necks. Like Chusyd, he also had to figure out what the models in the data meant by adapting the bears in captivity, observing them, and then matching those observations with the wildlife data. From finding the right bolting system to validating the data, it took Pagano a year to prepare to put the devices on bears in Alaska.
Accelerometers have certain limitations. Because Pagano relies on necklaces to attach his sensors, he can only tag bears; males have a neck that is larger than the head, which means the collars will slip off. And where the sensors are placed on the animal is really important, especially if scientists want to study a particular movement or behavior. At first, Pagano wanted to find movement patterns that could identify when bears were killing and eating seals. But because he had to attach the accelerometers to the neck collars, the sensors were unable to find separate signature patterns for these kill and eat movements, as these movements occur in other parts of the body. like hands and feet. Perhaps if the accelerometers were attached to the bears’ paws, they would be able to find this data – but there are just too many other head movements that the animals make for the sensors to pick up signals specific to the bear. hunting and food.