Overview
The Pacific Walrus (Odobenus rosmarus divergence) is a marine mammal renowned for its substantial size and distinctive tusks, primarily residing in the Arctic waters of the Chukchi and Bering Seas. As a cold-adapted species, it spends significant time on ice floes and coastal regions, often seen lounging or socializing in large groups. These ice floes provide a critical platform for activities like resting, molting, and giving birth, serving as a transient home for these marine giants.
The tusks of the Pacific Walrus are a defining feature, serving multiple utilitarian purposes essential for its survival. Made of elongated canine teeth, these tusks assist the walrus in foraging by excavating the ocean floor for its primary food source—mollusks such as clams. Additionally, the tusks function as leverage tools, helping the walrus to haul itself onto the ice. These canines can grow up to three feet long and are used in battles for dominance, particularly among males during mating season.
Another notable characteristic of the Pacific Walrus is its skin and fat. Adult individuals possess thick, wrinkled skin that is highly resistant to the cold Arctic conditions. Underneath this layer of skin is a substantial layer of fat, which can be as much as six inches thick. This fat serves a dual role: it acts as an energy reserve when food is scarce and as a vital insulator against the frigid temperatures of its native habitat. The fat enables the walrus to maintain its core body temperature, making it well-adapted to life in one of the planet’s most challenging environments.
Taxonomy
Kingdom
Phylum
Class
Order
Family
Genus
Species
Sub Species
Type
Physical Description:
The Pacific Walrus is a robust marine mammal, distinguished by its significant size and bodily features well-adapted for its Arctic habitat. Males are particularly larger than females, sometimes weighing twice as much. The walrus has a rounded head, complemented by a short muzzle and small eyes, characteristics that underscore its sturdy build. Its skin ranges from pinkish to brown and is notably thick, providing an essential barrier against the cold temperatures of its native waters.
Apart from its skin, one of the most distinctive features of the Pacific Walrus is its tusks. Both males and females are equipped with these elongated canines, although they tend to be longer and more massive in males. These tusks can reach lengths of up to 3 feet and serve multiple functions, including aiding in locomotion on ice and foraging on the ocean floor. Unlike its nearly hairless body, the walrus has specialized whiskers known as vibrissae. These sensitive bristles play a crucial role in helping the walrus locate and identify food in the ocean’s murky depths.
Lifespan: Wild: ~40 Years || Captivity: ~30 Years
Weight: Male: 2,200–3,700 lbs (1,000–1,678 kg) || Female: 880–2,700 lbs (400–1,224 kg)
Length: Male: 7.2–11.5 ft (2.2–3.5 m) || Female: 6–9.5 ft (1.8–2.9 m)
Height: Male: 50–60 inches (127–152 cm) || Female: 40–50 inches (101–127 cm)
Top Speed: 22 mph (35 km/h)
Characteristic:
Native Habitat:
The Pacific Walrus is native to the Arctic regions, most notably the Chukchi and Bering Seas in the northern part of the Pacific Ocean. These waters provide the essential conditions for their survival, including the presence of sea ice, which serves multiple functions in the life of a walrus. Sea ice is a platform for various activities, including resting, social interactions, and even giving birth. The walrus often uses these ice floes as staging areas for foraging expeditions into the ocean to find food, mostly benthic invertebrates like clams and mussels.
Seasonal movements are a significant aspect of Pacific Walrus behavior, governed primarily by the ebb and flow of the sea ice. During the summer months, as the ice begins to recede northwards, walruses follow it, always maintaining a close relationship with this vital environmental feature. Conversely, they move southward in the winter with the expanding ice cover. This seasonal migration allows them to stay in optimal conditions for both foraging and protection, as the ice provides a natural barrier against predators and adverse weather conditions.
Climate Zones:
WWF Biomes:
Biogeographical Realms:
Continents:
Countries:
Diet:
Diet & Feeding Habits:
The Pacific Walrus predominantly feeds on benthic invertebrates, organisms on the ocean floor. Their diet mainly consists of clams, mussels, and marine worms, which they locate using their highly sensitive whiskers, also known as vibrissae. These whiskers help them navigate the sediment and identify their prey, even in the dimly lit conditions of the Arctic ocean floor. Additionally, walruses employ their strong forelimbs to dig into the substrate, creating pits where they can suction feed, effectively extracting the soft parts of their prey from their shells.
Feeding is an intensive activity for the Pacific Walrus, and during a single session, they can consume up to 6% of their body weight in food. This high caloric intake is essential for maintaining their substantial blubber layer, which acts as an insulating material against the cold and an energy reserve. During fasting or when food sources are scarce, walruses rely on this stored energy to sustain their metabolic needs. The ability to store and utilize energy in the form of fat is vital for their survival, especially in the extreme conditions of their Arctic habitat.
Mating Behavior:
Mating Description:
The mating season for Pacific Walruses typically takes place between December and March, with the peak of the activity occurring in February. During this time, males employ various tactics to establish dominance and attract potential mates. One of the most prominent features used in these displays is their tusks, which serve functional roles in foraging and act as instruments of intimidation and hierarchy within the group. Males engage in aggressive behaviors, including physical confrontations such as tusk jabbing and body slamming, to assert their superiority and earn the right to mate with females.
In addition to physical confrontations, vocal displays are essential during the mating season. Males produce a variety of vocalizations, including roars, clicks, and bell-like sounds, to communicate their readiness to mate and establish their territory. These vocalizations serve multiple purposes, including warning other males to steer clear of an already claimed mate or are and attracting females who are ready to breed. The combination of physical prowess and vocal understanding contributes to the complex social dynamics that govern the mating behaviors of the Pacific Walrus.
Reproduction Season:
Birth Type:
Pregnancy Duration:
Female Name:
Male Name:
Baby Name:
Social Structure Description:
Pacific Walruses are inherently social creatures, often found in large herds that can number into the thousands. Outside the mating season, these herds are typically segregated by sex, with males and females forming separate groups. Within these groups, walruses exhibit various social behaviors, often interacting with each other through vocalizations and physical contact. The animals use a variety of grunts, bellows, and roars to communicate, serving functions from mating calls to alerts about potential danger.
The social structure of Pacific Walrus herds is hierarchical, particularly evident during the mating season. Dominant males, colloquially known as “beachmasters,” establish control over the harems of females and actively defend their position against rival males. These beachmasters use their tusks, body size, and loud vocalizations to establish and maintain dominance. Tusk displays are particularly critical in these power dynamics; the length and condition of a male’s tusks often signify his fitness and social standing within the herd.
Groups:
Population Trend:
The population of the Pacific Walrus is currently experiencing a decline, largely attributed to factors like melting sea ice, hunting, and escalating human activities in their native areas. The loss of sea ice due to climate change has profoundly impacted these animals. Sea ice is a crucial platform for resting, socializing, and launching foraging expeditions. The absence or reduction of these ice platforms makes it more challenging for walruses to access their food sources and rest, thereby increasing their vulnerability and affecting their overall well-being.
Accurately assessing the population size of the Pacific Walrus is fraught with challenges, primarily because of the remoteness of their habitat and the logistical difficulties involved in conducting extensive surveys. Despite these challenges, the estimated population hovers around 200,000 individuals. However, this approximation may not truly reflect the actual numbers, which could be higher or lower. The imprecise nature of these counts highlights the importance of ongoing conservation efforts to understand and mitigate the impact of various threats to this species.
Population Threats:
Climate change severely threatens the Pacific Walrus, particularly through the rapid melting of sea ice in their native Arctic regions. As the ice recedes, walruses are forced to congregate on land in large numbers, making them more susceptible to various dangers. Being on land exposes them to higher risks of predation from animals like polar bears and disturbance from human activities. Additionally, the absence of ice platforms complicates their ability to access their primary food sources on the ocean floor, increasing their vulnerability to malnutrition and other health issues.
Overharvesting is another significant threat to the Pacific Walrus population. They are hunted for various parts, including their valuable tusks, hides, and meat. While indigenous communities carry out some hunting, deeply embedded in their cultural practices, unsustainable hunting practices and illegal trade have added to the species’ decline. Measures like quota systems are often insufficient to prevent overharvesting, further exacerbating the pressures on an already stressed population.
Conservation Efforts:
Efforts to conserve the Pacific Walrus have been multifaceted, focusing on regulatory and monitoring initiatives. One of the primary steps has been the implementation of quotas on hunting, aimed at ensuring that any harvesting is sustainable and does not contribute to population decline. Alongside this, strict regulations have been implemented to control industrial activities, such as oil drilling and shipping, within the walruses’ native habitats. These regulations are designed to minimize disturbances and potential hazards to the animals, providing a more secure environment for them to thrive.
Monitoring programs have also been established to keep track of the changing conditions in sea ice and how these fluctuations affect walrus populations. Satellite imagery and on-ground surveys are utilized to study sea ice patterns and walrus behavior, providing valuable data to inform conservation strategies. The concept of protected marine areas is also considered a potential conservation tool. These would serve as designated zones free from human activity, providing safe havens where Pacific Walruses could rest, socialize, and feed without the immediate threats posed by hunting or industrial operations.
Additional Resources:
Fun Facts
- Pacific Walruses can sleep while floating on water.
- They have a layer of fat that can be as thick as 6 inches.
- They can dive as deep as 630 feet to forage for food.
- A walrus’s tusks can grow up to 3 feet in length.
- They use their tusks to haul themselves onto ice and to break breathing holes in the ice.
- Male walruses are called “bulls,” females are “cows,” and the young are “calves.”
- They have been known to occasionally prey on seals.
- Walruses are sensitive to environmental changes and are considered an indicator species for climate change.
- They have air sacs in their necks that allow them to keep their heads above water while sleeping.
- Despite their large size, walruses are agile and can swim up to 22 mph.
