Stejneger's beaked whale
This is the northernmost species of beaked whale in the Pacific Ocean, ranging up into the Bering Sea. They are distributed along both sides of the Pacific to Miyagi Prefecture, Japan and southern California.
Stejneger's beaked whale (Mesoplodon stejnegeri), sometimes known as the Bering Sea beaked whale or the saber-toothed whale, is a poorly known member of the genus Mesoplodon inhabiting the northern North Pacific Ocean. Leonhard Hess Stejneger collected the type specimen (a beach-worn skull) on Bering Island in 1883, which provided the description by Frederick W. True in 1885. In 1904, the first complete skull (from an adult male that had stranded near Newport, Oregon) was collected, which confirmed the species' validity. The most noteworthy characteristic of the males is the very large, saber-like teeth, hence the name.
The body for this species is rather typical for a mesoplodont, long and tapering at both ends. The beak of the whale is of medium length, and the mouthline forms an arch, though much smoother than other species. The teeth of the males are much larger than those of most other mesoplodonts and point forwards and inwards right in front of the apex. Only strap-toothed whales and spade-toothed whales have longer teeth. The coloration is overall dark gray to black on the body with light coloration below, and around the head giving it a "helmeted" appearance. The coloration darkens with age, but females have a light pattern on the bottom of the flukes that becomes more apparent with age. Like most species, scars occur on the males (from other males) and cookiecutter shark bites are present on both sexes.
The length is at least 5.25 meters (17 feet 6 inches) for males and 5.5 meters (18 feet) for females. They are likely around 2.1 to 2.3 meters long
(7 to 8 feet) when born.
Their preferred diet is primarily deep-water squid, but also benthic and benthopelagic fish and some crustaceans, mostly taken near the sea floor.
In a recent study, gouge marks in the seafloor were interpreted to be a result of feeding activities by beaked whales.
Very little is known about the life histories of beaked whales. There are currently no data available on their reproductive rates.
The whales are typically found in groups of three
to four and sometimes up to 15 animals in a very close group. The groups may have age and sex segregation. Adult males fight each other extensively, and some specimens have been found with healed jaw fractures.