Australian fur seal, Arctocephalus pusillus doriferus

Detailed introduction

The Australian fur seal (scientific name *Arctocephalus pusillus doriferus* ) is one of the larger antherid marine mammals of the Southern Hemisphere, belonging to the genus *Arctocephalus* in the family Sealidae. It is a subspecies of the brown fur seal found in Australian waters, belonging to the same species as the South African fur seal found near the coast of Africa, but differing slightly in distribution, physical characteristics, and ecological habits. Today, the Australian fur seal is one of the most common large seals in the waters off southern Australia.

Classification and nomenclature

The Australian fur seal belongs to the class Mammalia, order Carnivora, superfamily Pinnipedia, family Otariidae, and genus Arctocephalus . Its scientific name is often written as *Arctocephalus pusillus doriferus* , and it is the Australian subspecies of the brown fur seal *Arctocephalus pusillus *, therefore it is sometimes collectively referred to as the "brown fur seal" or "African-Australian fur seal." The subspecies name "doriferus" is often used to distinguish it from the South African *A. p. pusillus* and the Australian *A. p. doriferus *.

Appearance features

Australian fur seals are robust and powerfully built, among the largest fur seals in the Southern Hemisphere. Adult males typically measure 2.0–2.3 meters in length and weigh over 180–220 kilograms; females measure 1.2–1.8 meters in length and weigh approximately 35–80 kilograms. Sexual dimorphism is very pronounced. Males have large heads, thick necks, and prominent shoulders and backs, with distinctive, coarse mane-like fur, giving them the appearance of a "sea lion." Females are relatively slender with more delicate necks.

The fur color is primarily dark brown to grayish-brown, with a darker back and sides, and a slightly lighter chest and abdomen; the overall color may appear slightly duller after the winter molt. Newborn pups have darker fur, close to blackish-brown, which changes to light brown or silvery-gray down after a few months. Unlike true seals, fur seals have prominent external ears, robust, fur-covered forelimb flippers, and hind limb flippers that can fold forward to support their bodies, allowing them to walk nimbly on land and climb rocks.

Distribution range and habitat

Australian fur seals are relatively concentrated, primarily found in the Bass Strait and surrounding waters of southern Australia. Breeding colonies are almost entirely located on nine islands in Victoria and Tasmania, with Seal Rocks in Victoria being one of the largest breeding grounds. Outside the breeding season, individuals roam a wider area, ranging from Kangaroo Island in South Australia to the surrounding areas of Tasmania and the southern coast of New South Wales. They prefer steep reefs, offshore rocky islands, reef platforms, and gravel beaches, but sometimes also gather to rest or breed on more open beaches.

Lifestyle Habits and Behaviors

Australian fur seals spend most of their time foraging and migrating at sea, only coming ashore in large groups during the breeding season and molting period. They are skilled swimmers and divers, easily climbing steep rocks and diving to depths typically ranging from tens to over a hundred meters, with some records exceeding 130 meters. Adult males establish territories at breeding grounds, using vocalizations, displays of strength, and physical contact to drive away competitors. The social structure of the group is relatively loose, but there is a strong bond between females and pups, who gather on land in kindergarten-like play groups.

feeding habits

Australian fur seals are mesophobic to trophic level predators, primarily feeding on fish and cephalopods. Studies show that their diet typically consists mainly of small, mid-to-upper-level fish, such as those in the orders Clupeiformes and Perciformes, followed by cephalopods like squid and cuttlefish. They also consume crustaceans and some large invertebrates. Individuals actively pursue prey on the seabed or in the upper and middle layers of the water, using their flexible forelimbs and powerful tails to maneuver quickly through complex reefs and seabed terrain.

Reproduction and life cycle

The breeding season for Australian fur seals primarily occurs between November and December. Males arrive at the breeding grounds early and establish small territories, followed by females giving birth. Each female typically gives birth to one pup per year, with newborns weighing approximately 4–7 kg and covered in dark downy fur. Shortly after giving birth, the female can mate again, but implantation is delayed, resulting in an actual gestation period of about one year. The pups nurse on land for several months before gradually learning to forage in the sea with their mothers. In the wild, individuals typically live to be 15–20 years old, with a few exceeding this age.

Relationship with humans

During the 18th and 19th centuries, Australian fur seals were overhunted for their fur and grease, nearly driving them to extinction. Since the 20th century, with the ban on commercial hunting, their population has gradually recovered, now reaching tens of thousands, though still below historical levels. In recent years, regular seal-watching tours have emerged in several coastal areas of southern Australia, allowing tourists to observe seals in groups near their breeding grounds from boats or viewing platforms. However, conflicts also exist between them and coastal trawlers, such as bycatch due to accidental entry into nets and the perception of seals as "pests" when competing for fish.

Protecting the status quo and threats

Globally, the Australian fur seal (including the Australian subspecies) is generally classified as "Least Concern (LC)" on the IUCN Red List, indicating that its overall population is currently relatively stable. However, in some Australian waters, the Australian fur seal still faces potential impacts from bycatch, marine debris entanglement, coastal habitat disturbance, and climate change on marine productivity and prey distribution. In some regions (such as New South Wales), it is also listed as a regionally vulnerable or concerned species. Continuous monitoring of breeding ground populations, improving fishing gear design to reduce bycatch, controlling nearshore pollution, and maintaining appropriate distances and regulated viewing practices during tourism activities are important directions for the future conservation of the Australian fur seal.