A walrus oosik is the baculum, or penis bone, of a male Pacific or Atlantic walrus, and it ranks among the largest such bones in the animal kingdom, often reaching 50 to 60 centimeters in length in fully mature bulls. The word “oosik” comes from Yupik, one of the Indigenous languages of coastal Alaska, and the object has been valued for centuries across Arctic cultures for both practical and ceremonial uses. Today, polished oosiks are sought after as curiosities, carved art objects, and collector’s items, trading hands for hundreds or even thousands of dollars depending on size, condition, and craftsmanship.
The Bone Itself
Most people are surprised to learn that many mammals have a bone inside the penis. Humans are among the minority that lack one. The baculum is embedded in the connective tissue of the penis and provides structural rigidity during mating. In walruses, this bone is dense, slightly curved, and tapers toward the tip. It is composed of true ossified bone tissue with a marrow cavity, not cartilage or kerite like a tusk. When dried and cleaned, it has a smooth, ivory-like surface that takes a polish well, which is one reason it has long attracted artisans.
Research on Atlantic walruses in the North Water region of Baffin Bay found that the baculum grows gradually until bulls reach physical maturity at roughly 12 to 15 years of age.1Marine Mammal Science. REPRODUCTION IN MALE ATLANTIC WALRUSES (ODOBENUS ROSMARUS ROSMARUS) FROM THE NORTH WATER (N BAFFIN BAY) That prolonged growth period means the bone serves as a rough gauge of the animal’s age and overall size. A truly large oosik, well over half a meter long, came from a mature bull that likely weighed over a metric ton. The sheer scale of the bone is part of its appeal as a novelty item and conversation piece.
Why It Gets So Large
Walruses belong to the order Carnivora, and across carnivores, baculum size varies enormously. A house cat’s is tiny; a walrus’s dwarfs almost every other land or marine mammal’s. Researchers have investigated why some carnivores evolved disproportionately large penis bones, and the answers point to a combination of environment, mating behavior, and reproductive timing.
A comparative study across carnivore species found that longer bacula tend to show up in species living at high latitudes with heavy snowfall, in species with delayed implantation of embryos, and in species where females mate with multiple males. Conversely, the smallest bacula appeared in strictly polygynous species where a single dominant male monopolizes mating. The researchers concluded that seasonal resource pressures and environmental constraints on movement shaped mating systems, which in turn drove sexual selection for larger penis bones.2Oikos. Are long penis bones an adaption to high latitude snowy environments? Walruses check several of those boxes: they live in Arctic environments, experience extreme seasonality, and have a mating system in which competition among males is intense.
From a paleontological perspective, the trend toward a larger baculum appears early in walrus evolutionary history. Fossil evidence shows that increased baculum size is one of several major developments in walrus evolution alongside tooth simplification, larger body size, the growth of tusks, and a distinct style of locomotion adapted for both land and water.3Academic Press. The surprising evolutionary heritage of the Atlantic walrus as chronicled by the fossil record In other words, a substantial penis bone has been part of the walrus blueprint for a very long time, not a recent quirk of one population.
Mating Season Violence and Baculum Fractures
If you are wondering whether a bone that large, inside an organ under that much stress, ever breaks, the answer is yes. Researchers examining walrus and other carnivore bacula have documented healed fractures, and the most likely cause is aggression between males during the breeding season. Rival bulls weighing over 1.2 metric tons can charge or land on a mating male, and the resulting force is enough to snap the bone mid-copulation.4International Journal of Osteoarchaeology. Baculum fracture in carnivores: osteological, behavioural and cultural implications The evidence suggests that younger, lower-ranking males were especially vulnerable to this kind of injury, because dominant bulls are more likely to attack them during mating attempts. A fractured baculum could temporarily or permanently exclude the injured male from breeding, making it a real fitness cost of being outranked.
For collectors, a healed fracture visible on a cleaned oosik is not necessarily a defect. Some buyers and carvers consider it a mark of authenticity and a story in itself, evidence that the bone came from a wild animal that survived a violent encounter. The callus of healed bone is often clearly visible as a thickened ridge along the shaft.
Cultural Significance in Arctic Communities
Native communities along the Bering and Chukchi seas have relied on walruses for food, tools, clothing, and cultural materials for thousands of years. The relationship between these communities and walruses is not simply economic; it is woven into social identity, spiritual practice, and intergenerational knowledge.5PubMed. Sustaining a healthy human-walrus relationship in a dynamic environment: challenges for comanagement Almost every part of the walrus has a traditional use, and the baculum is no exception. Historically, oosiks were used as clubs, handles, or other tools, and they were sometimes carved into decorative or ceremonial objects.
In contemporary Alaska, skilled Yupik and Inupiaq artisans carve oosiks with scrimshaw designs, etch scenes of Arctic life into the polished surface, or shape them into stylized sculptures. These finished pieces are sold in galleries, tourist shops, and online marketplaces throughout the state and beyond. A raw, uncarved oosik in good condition might sell for a few hundred dollars; a finely carved one by a known artist can fetch considerably more. The market for these objects overlaps with the broader market for walrus ivory carvings and scrimshaw, which has its own long tradition in the region.
It is worth understanding that the oosik trade is not a relic of the past. It is a living part of the subsistence economy in remote Alaskan villages where cash income is scarce and the cost of goods is extremely high. Selling carved walrus parts, including oosiks, ivory, and bone, provides real economic support to communities that are simultaneously dealing with rising fuel costs, changing ice conditions, and limited access to wage employment.
Legal Rules Around Buying and Selling Oosiks
If you see an oosik for sale at a shop in Anchorage or listed on an online marketplace, the legality depends on where it came from and who processed it. Walruses are protected under the Marine Mammal Protection Act in the United States, which generally prohibits the take, possession, and sale of walrus parts by non-Natives. However, Alaska Natives are permitted to hunt walruses for subsistence purposes and to carve, use, and trade walrus parts, including oosiks.6Biodiversity and Conservation. Native American ivory carving in Bali and the international back-and-forth trade in walrus ivory and bones between Indonesia and the USA
Internationally, walrus trade falls under the Convention on International Trade in Endangered Species (CITES), which means shipping an oosik across a national border requires proper documentation and permits. This regulatory layer exists because walrus populations have historically been vulnerable to commercial overexploitation, and unregulated trade in parts could incentivize unsustainable hunting. Within the U.S., the key distinction is between raw walrus parts (which can only be legally sold by Alaska Natives) and “significantly altered” Native handicrafts (which can be resold by anyone once they have been legally crafted). A polished and carved oosik typically qualifies as a Native handicraft, but an uncarved raw bone in a non-Native’s possession could raise legal questions.
Buyers outside Alaska should be cautious about provenance. Reputable dealers provide documentation of the item’s origin and the identity of the Native artisan. If you are purchasing online and the seller cannot explain the chain of custody, that is a red flag. Enforcement actions against illegal walrus ivory and bone sales do happen, and ignorance of the law is not a defense under the Marine Mammal Protection Act.
Oosik Versus Walrus Ivory
People sometimes confuse oosiks with walrus tusks or lump them together under the general category of “walrus ivory.” They are different materials. Walrus tusks are elongated canine teeth composed of dentine, with a distinctive cross-sectional grain pattern that distinguishes them from elephant ivory. An oosik, by contrast, is true bone. It has a different texture, a different internal structure, and responds differently to carving tools. When polished, the surface of an oosik tends to be smoother and more uniform than tusk ivory, which has a marbled or oatmeal-like grain when viewed in cross section.
In the collector market, walrus tusks generally command higher prices than oosiks of comparable size, partly because tusks have a longer and more widely recognized history as a carving medium and partly because their material properties allow finer detail in scrimshaw work. But oosiks have their own niche appeal precisely because of what they are. The novelty factor is real: an object that large, that ancient in evolutionary terms, and that unmistakably anatomical generates curiosity in a way that a tusk does not. Museum gift shops, oddity collectors, and buyers of natural history specimens form a steady market for well-preserved examples.
Climate Change and the Future of Walrus Hunting
The availability of oosiks on the commercial market is ultimately tied to the health of walrus populations and the ability of Native hunters to harvest them. Both are under growing pressure from climate change. Sea ice loss in the Arctic has accelerated dramatically over the past few decades, and walruses depend on sea ice as a platform for resting, giving birth, and accessing benthic feeding grounds. When ice retreats far from the continental shelf, walruses are forced onto land in enormous and sometimes deadly aggregations called haulouts.
A 2023 workshop held in Nome, Alaska, brought together experienced Yupik walrus hunters from St. Lawrence Island and federal walrus biologists to discuss the impacts of climate change on the Pacific walrus population. The participants noted that while current harvest rates remain sustainable, the combination of shifting sea ice, changing weather patterns, and increased industrial activity in walrus habitat poses growing threats to both the animals and to hunting safety and success.7Arctic Science. Co-producing knowledge about the Pacific walrus and climate change Hunters reported that ice conditions have become less predictable, making traditional knowledge about safe travel routes less reliable and sometimes forcing hunters to travel much farther from shore.
The Eskimo Walrus Commission works with the U.S. Fish and Wildlife Service under a co-management agreement to monitor walrus populations, set harvest guidelines, and incorporate Indigenous knowledge into management decisions.5PubMed. Sustaining a healthy human-walrus relationship in a dynamic environment: challenges for comanagement This co-management model is considered relatively progressive among marine mammal governance frameworks, because it gives weight to the observational expertise of hunters who spend their lives on the ice alongside the animals. But the pace of environmental change is testing the model’s adaptability. If walrus populations decline or shift their range significantly northward, the downstream effects on subsistence hunting, and by extension on the supply of legally sourced walrus bone and ivory entering the art and collector markets, would be substantial.
Fossil and Beach-Found Oosiks
Not every oosik on the market comes from a recently harvested walrus. In parts of Alaska and the Russian Far East, ancient oosiks erode out of coastal bluffs, riverbanks, and old village sites where they were discarded or lost centuries or millennia ago. These fossil or subfossil specimens can be heavily mineralized, sometimes taking on colors ranging from deep brown to almost black depending on the minerals they absorbed during burial. Collectors prize these aged specimens for their patina and geological character, and they sell alongside more recently harvested ones.
The legal status of beach-found or fossil oosiks is murkier than that of freshly harvested ones. Under federal law, walrus remains found on public land in Alaska are generally considered the property of the federal government, and collecting them without authorization can violate the Marine Mammal Protection Act. On Native-owned lands, the rules differ, and the specific land status matters. If you find what looks like an ancient walrus bone on a beach in Alaska, the legally safest course is to leave it where it is and contact the relevant land manager. Plenty of people do pick up old bones, but the enforcement risk is real, especially if the item later appears in commerce.
Mineralized specimens also present an identification challenge. A heavily fossilized oosik can be difficult to distinguish from other large mammalian limb bones without some expertise. Reputable dealers selling fossil oosiks will usually point out anatomical features that confirm the identification: the characteristic curvature, the flattened cross section, and the overall proportions that distinguish a baculum from, say, a walrus rib or a long bone from another marine mammal.