A new study by the National Institute of Polar Research in Japan found that great white sharks, despite body temperatures that are often warmer than their surroundings, prefer to hunt seals and other prey at slower speeds.
These findings, published in this month’s Journal of Experimental Biology, are in contrast to how most endothermic predators hunt.
The research team of Yuuki Watanabe, Nicholas Payne, Jayson Semmens, Andrew Fox and Charlie Huveneers, attached sensors to ten adult great whites to detect their movements, swim speeds and depth in the Neptune Islands Group Marine Park off the coast of South Australia. The detachable devices showed that when the sharks were in the vicinity of seal colonies, they moved sluggishly.
“This strategy is as close to a ‘sit-and-wait’ strategy as is possible for perpetual swimmers, such as white sharks,” Watanabe said.
This was unexpected, because swimming becomes costly and inefficient at very low speeds. Watanabe suggested that the animals may benefit from their profligacy when cruising along by increasing their chance of encountering a fat seal to dine on. Even though great white sharks are capable of swimming fast thanks to their warm muscles, using that efficiency may not provide an advantage when looking for food.