The Baird’s Beaked Whale, Berardius bairdii, is a large, deep-diving marine mammal that remains largely enigmatic to science. These whales are among the largest of the beaked whale family. Named after Spencer F. Baird, a naturalist from the late 1800s, this species is known for its elusive behavior in deep oceanic waters.
Physical Description and Deep-Diving Adaptations
Baird’s Beaked Whales are large animals, with females typically larger than males, reaching lengths of up to 42 feet (12.8 meters) and weighing around 12 tons (11,000 kg). Their bodies are long and cylindrical, tapering towards both the head and tail. Their coloration ranges from blue-gray to brown to black on the upper side, with lighter gray undersides. A distinctive feature is their high, bulbous forehead, or melon, which slopes steeply into a long, thin beak.
Adult males possess two pairs of prominent teeth that protrude from their lower jaw. These teeth, often covered in scars, are thought to be used in competitive interactions between males. The whales have a small, triangular dorsal fin located about two-thirds of the way back on their body. Their flippers are small and rounded, fitting into depressions in their body called “flipper pockets” which may reduce drag during dives.
These whales are highly adapted for extreme deep diving, a necessity for their foraging habits. They can hold their breath for extended periods, with dives lasting between 11 and 30 minutes, and some recorded up to 81.7 minutes. They descend to depths exceeding 3,300 feet (1,000 meters), with dives reaching up to 9,840 feet (nearly 2 miles). Their physiology allows them to cope with immense pressure and low oxygen, including a higher blood-to-body-volume ratio, increased red blood cell concentration for oxygen transport, and high levels of myoglobin in their muscles for oxygen storage. They also have collapsible lungs, which help prevent decompression sickness.
Habitat, Diet, and Elusive Nature
Baird’s Beaked Whales inhabit the cold, deep oceanic waters of the North Pacific Ocean and adjacent seas, including the Bering Sea, Sea of Japan, and Okhotsk Sea. Their distribution extends from Japan and southern California northward to the Bering Sea. They prefer depths beyond the 1,000-meter line and are often found near underwater geological structures like submarine canyons and seamounts, which tend to have abundant prey.
Their diet consists of deep-sea squid and various deep-sea and open-ocean fish, such as mackerel, sardines, and saury. They also consume crustaceans, sea cucumbers, and octopus. These whales likely use echolocation to navigate and locate prey in the dark depths. They employ “suction feeding,” using their throat grooves to rapidly expand their oral cavity and draw in prey.
The elusive nature of Baird’s Beaked Whales makes them challenging for scientists to study. Their deep-diving habits mean they spend prolonged periods underwater, often surfacing for only brief intervals. Their blow, the spout of water vapor they exhale, is low and indistinct, contributing to their infrequent detection at sea. Most information about these whales has been gathered from stranded individuals or limited observations from a distance.
Social Structure and Vocalizations
Baird’s Beaked Whales are social animals, forming groups ranging from 3 to 10 individuals, with larger aggregations up to 50 observed. Within these groups, they often exhibit synchronized behaviors, such as surfacing and breathing in unison. The presence of white scars and scratches on the backs and beaks of adult males suggests aggressive interactions, related to competition for breeding.
Like other toothed whales, Baird’s Beaked Whales rely on sound for navigating, foraging, and communicating within their deep-sea environment. They produce echolocation clicks, which are high-frequency sound waves that bounce off objects, providing them with information about their surroundings and prey.
Beyond echolocation, they also use other vocalizations, such as whistles and burst pulses, for communication. Studying their vocalizations is difficult due to their deep-diving habits. However, passive acoustic monitoring has become a tool for understanding their distribution and behavior by detecting their unique sound signatures.
Conservation Status and Threats
The International Union for Conservation of Nature (IUCN) classifies Baird’s Beaked Whale as “Least Concern.” However, this classification comes with caveats due to limited data on their global population size. While not listed as endangered or threatened under the U.S. Endangered Species Act, they are protected under the Marine Mammal Protection Act.
Despite their current status, Baird’s Beaked Whales face several threats. Entanglement in fishing gear is a primary concern. Historically, commercial whaling, primarily by Japan, Russia, Canada, and the United States, significantly impacted their populations, with Japan still maintaining a quota for their harvest.
Underwater noise pollution poses another threat, particularly from naval sonar, seismic surveys for oil and gas exploration, and shipping vessels. Beaked whales, including Baird’s, are sensitive to human-made noise, which can disrupt their echolocation-based foraging and communication, leading to behavioral changes or stranding events. Climate change also presents a challenge, as changing ocean temperatures and currents could alter the distribution and abundance of their deep-sea prey. Ongoing research efforts, including acoustic monitoring and studies on stranded whales, provide insights, aiding in their protection.