Among them, there are 16 species in the Beaked Whale genus, which is the largest genus among cetaceans. The genus includes some lesser-known marine mammals — so much so that three new species of these rhino-sized whales have been discovered in the past 30 years. Most species are physically very similar and are considered specialized deep-sea predators. Furthermore, they are often found in the same area and forage at similar depths. This raises the question of how they can avoid competition with each other for the same prey.
For some beaked whale species, biotags attached to their backs with suction cups suggest that they generally have a low-energy lifestyle: They are capable of extreme deep dives through slow, energy-saving swimming and hunting strategies. But the Sowerby beaked whale has never been tagged before. After years of work, however, the team was able to deploy biotags on two Sorbbie’s beaked whales. The tags document details about the diving, locomotion and echolocation strategies of these extremely shy animals, providing the first opportunity to study their foraging behavior. This puts their hunting strategies in direct comparison with those of their close relatives, the slow-moving Blainville’s beaked whale.
To the researchers’ surprise, Thorby’s beaked whales differed significantly from other Mesozoic species in their swimming and hunting strategies. Although their foraging depths were similar (800-1300 m), they consistently swam faster, made shorter deep dives and made higher frequency clicks to echolocate faster. This first record of “fast” beaked whales suggests that mid-beaked whales exploit a wider diversity of deep-sea niches than had been suspected so far. The deep ocean is a rich and diverse hunting ground for marine mammal predators, who have apparently developed a wider range of specialized strategies than before to be able to exploit it. The apparent departure from the typically slower behavior of other beaked whales also has potential implications for their response to artificial sounds, which appear to be strong behavioral drivers in other species.