Marine Mammal of the Month Summer 2020

Marine Mammal of the Month: Cuvier’s Beaked Whale
By: Alexandrya Robinson

Cetaceans are grouped into two categories, odontocetes (toothed cetaceans) and mysticetes (baleen cetaceans). One such odontocete is the Cuvier’s beaked whale; named by Georges Cuvier, who discovered a skull fragment which he mistook for the fossilized remains of an extinct species. Cuvier named this whale Ziphius cavirostris because of its prominent hollow basin in its skull where the blowhole is situated. In fact, is the only species within the genus Ziphius. The structure of the Cuvier’s beaked whale’s skull has led it to be known also as the goose-beaked whale. Cuvier’s beaked whale was long thought to be extinct because it primarily resides in the bathypelagic zone of the ocean, migrating occasionally to the abyssopelagic zone. It was discovered to still be alive only after Cuvier’s death. Interestingly, although being a pelagic species, this whale is also a commonly beached whale and one of the most commonly sighted beaked whales. There is still a lot of mystery surrounding Cuvier’s Beaked Whale because of their ability to dive so deep and hold their breath so long. In fact, this species can dive deeper and hold their breath longer than any other marine mammal! These whales are born around 2.7 meters long and can grow to be around five to seven meters long. As adults, they can weigh two to three tons. Cuvier’s beaked whales tend to vary in color, and can most reliably be identified by their short, goose-like beak and bulbous heads. Additionally, males have protruding teeth in their upper jaws which are used for fighting and produce distinctive scarring on the flanks of other males. There has not been extensive research on the life cycle of this species, but recorded sightings have indicated that this organism lives in small pods of 2 to 15 whales. This whale species does migrate to the surface of the ocean to feed on fish and breathe, but has also been recorded to have a diet consisting of squid and crustaceans as well. They are widely distributed, living in offshore waters all around the globe. Some human threats to these whales are ocean bycatch, pollution, hunting, and ocean noise, to which these whales appear particularly susceptible. Accidental beaching also seem to pose a great danger for these whales. To learn more about these fascinating creatures and how they are protected, visit: https://www.fisheries.noaa.gov/species/cuviers-beaked-whale#conservation- management.