The term “oosik” refers to the dense bone found within the male reproductive anatomy of certain Arctic marine mammals. While the bone is present in many species, the word is specifically used by Alaska Native cultures, particularly the Iñupiaq and Yupik, to describe the baculum of the walrus. The bone’s remarkable size and durability have made it a significant material for art and tools for centuries.
The Biological Purpose of the Baculum
The anatomical structure known as the baculum, or os penis, is a heterotopic bone, meaning it is not connected to the main skeleton. This bone is present in the penises of many placental mammals, including most carnivores and primates. The walrus, a member of the Carnivora order, possesses a particularly prominent example of this bone.
The primary function of the baculum is to provide structural rigidity during copulation. The bone allows the male to achieve and maintain intromission without relying solely on hydraulic blood pressure, which is the mechanism used by mammals lacking the bone, such as humans.
For the walrus, which mates in the harsh, frigid environment of the Arctic, the baculum may facilitate prolonged copulation. This extended intromission is a strategy that can increase the likelihood of fertilization and aid in sperm competition among males.
Physical Characteristics and Identification
The walrus oosik is notable for being the largest baculum of any pinniped and one of the largest in the animal kingdom. A full-grown Pacific walrus can possess an oosik measuring up to 60 centimeters (about two feet) in length. Fossilized specimens from extinct walrus species have been discovered that measure an astonishing 1.4 meters (about 4.5 feet) long.
The bone itself is dense and heavy, typically exhibiting a slight curve and a tapered shape. Its color ranges from a creamy white, characteristic of newly acquired bone, to a dark, yellowish, or brownish hue when fossilized after being buried in sediment or permafrost.
The oosik is sometimes mistaken for true walrus ivory, which comes from the animal’s tusks. Although both are hard, durable materials, the oosik is anatomically distinct from the tusk and lacks the cross-hatch or Schreger lines that characterize true ivory. Its sheer size and distinct curvature make it easily identifiable among other bacula.
Cultural History and Legal Trade Status
For centuries, the oosik has been a valuable material for the Indigenous peoples of the Arctic, including the Inuit and Yupik. The bone’s strength and size made it ideal for practical applications in a challenging environment. Historically, oosiks were fashioned into functional items, such as tools, weapons, handles for knives, and components for harpoon assemblies.
The material has also been used for intricate carvings, particularly in recent history as a form of cultural art sold to outsiders. The oosik is highly valued as a collectible, linking it to both ancient utility and modern artistic expression.
The trade of walrus parts, including the oosik, is subject to strict governmental regulation, particularly in the United States under the Marine Mammal Protection Act (MMPA) of 1972. This law prohibits the import, export, and sale of marine mammal parts, though there is a significant exception for Alaska Native people. They are permitted to hunt walruses for subsistence and to create and sell authentic handicrafts from the remains.
The MMPA distinguishes between newly harvested bone and “pre-act” artifacts, which were created before 1972. Pre-act oosiks and those legally carved by Alaska Natives are generally permitted for domestic trade, provided they can be authenticated. International trade is further complicated by CITES, which lists the walrus and imposes additional documentation requirements for cross-border movement.