Emily Chan
They consume their prey by sucking up water and sediment from the seafloor. Then, they use their baleens to filter the food.
Usually, gray whales are observed alone or in small groups, but large groups may gather at feeding or breeding grounds.
Bird and colleagues conducted their research off Newport on sailing trips over seven years. They used drones to track and record individual whales.
From 2016 to 2022, the team tracked 78 gray whales. They observed that younger, smaller whales tended to swim sideways or facing forward. The whales also opened and closed their mouths to find and consume food.
Meanwhile, older, bigger whales often dive and stay in place with their head down underwater. Scientists called it the “headstand technique.” As a whale got larger, the chances of such headstands being performed grew more likely.
At the same time, the probability of the forward-swimming strategy decreased. Water depth and habitat type—sandy, rocky, or coral reef—also influenced the whales’ approaches.
The switch between techniques is attributed to the maturity of a whale’s muscles, as well as its levels of coordination and strength.
When older, bigger whales search for food, they typically release air from their blowholes to help them stay underwater.
The “bubble blasts” help whales sink since the bigger they are, the more prone to floating they are. On average, a bubble blast appeared about 27 seconds after a whale dove for food. Most of them occurred while the whales were doing headstands.
There is still so much that is unknown about whales and their behavior. The drone footage helps provide details that researchers would otherwise miss.
The study was published in Ecology and Evolution.
