Fur seals and sea lions are distinguished from other seals by their external ear flaps and hind flippers which rotate forward, allowing them to move quickly on land.
New Zealand fur seals can be distinguished from sea lions by their pointy nose and smaller size. In New Zealand, fur seals also tend to be found on Rocky shorelines, whereas sea lions prefer sandy beaches.
This pointy-nosed seal has long pale whiskers and a body covered with two layers of fur. Their coat is dark grey-brown on the back, and lighter below; when wet kekeno look almost black. In some animals the longer upper hairs have white tips which give the animal a silvery appearance.
Adult females: maximum length 1.5 m, weight 30-50 kg.
Adult males: maximum length 2.5 m, weight 90-150 kg.
In New Zealand fur seals are found on rocky shores around the mainland, Chatham Islands and the Subantarctic islands (including Macquarie Island). They are also found much further afield in South Australia, Western Australia and Tasmania.
Breeding colonies occur as far north as the Coromandel peninsula and as far south as the Subantarctic islands. They are even seen north of Auckland on occasion.
Diet and foraging
The New Zealand fur seal/kekeno feed mainly on squid and small mid-water fish but also take larger species such as conger eels, barracuda, jack mackerel and hoki, mostly off the continental shelf.
They dive deeper and longer than any other fur seal. Female fur seals on the West Coast are known to (occasionally) dive deeper than 238 m, and for as long as 11 minutes.
New Zealand fur seals’ dive patterns reflect the movement patterns of their prey
Off Otago, New Zealand fur seal’s prey stay very deep underwater during the day, and then come closer to the surface at night. Here, fur seals feed almost exclusively at night, when prey is closer to the surface, as deep as 163 m during summer.
Their summer foraging is concentrated over the continental shelf, or near the slope. They will dive continuously from sundown to sunrise.
In autumn and winter, they dive much deeper with many dives greater than 100 m. At least some females dive deeper than 240 m, and from satellite tracking they may forage up to 200 km beyond the continental slope in water deeper than 1000 m.
Once at the brink of extinction
Before the arrival of humans a population of about 2 million fur seal/kekeno inhabited New Zealand. They were taken as food by Māori, and the onset of European sealing for meat and pelts in the 1700s and 1800s pushed them to the brink of extinction.
On the way to recovery
In 1978 fur seal/kekeno were fully protected by the Marine Mammals Protection Act, and they have continued to grow in numbers ever since. Research in Otago has shown a population increase of 25% per year between 1982 and 1994. Surveys in 1995 indicated this was continuing.
A similar rate of increase has been noted in the Nelson/Marlborough region and also in the sub-Antarctic Bounty Islands. Since 1991, fur seals have recommenced breeding on the North Island. In Australia population increases may range from 16 to 19% per year.
Although there are no estimates of population growth available for Southland, a nationwide survey in the 1970’s showed fur seals in Southland accounted for over 40% of the total New Zealand population or 70% if the Subantarctic islands are included.
West Coast South Island population in decline
Although fur seals/kekeno are recovering in most of the country, a decline has been recorded in some colonies on the West Coast of the South Island. One of the possible reasons for this is the ongoing accidental capture of mature females in the winter fishery for spawning hoki.
New Zealand fur seal/kekeno spend a lot of their time on rocky shores, at sites called haul-outs. Every year, these sociable animals return to the same area for the breeding season.
Their haul out sites can get noisy! Fur seals make calls for many reasons. For example, males use vocalizations during threat displays, and females and pups often vocalize when trying to find each other after a foraging trip.
Listen to this 30 second clip of New Zealand fur seals on the Razorback, north-east coast of Stephens Island (MP3, 736K).
This clip is of a group of seals resting on rocks, or swimming close by, competing for resting spaces and occassionally calling.
On average, they live 14 to 17 years.
Females will have their pup between 4 and 6 years of age, and continue giving birth to a single pup every year until their death.
Males are sexually mature at 5 to 6 years, but are unlikely to be socially mature (able to hold a territory and sire pups) for at least another 3 years.
The breeding season
The breeding season takes place from mid-November to mid-January. During this time, seals mate and females give birth to their pups.
Dominant bulls put on displays of glaring and posturing and fighting with other males just prior to the breeding season to gain territories. Fur seals are polygamous breeders; this means that a male may mate with many females in a single breeding season.
Females mate 6 to 8 days after the birth of their pup, even before their first foraging trip. To ensure that the next pup is born during the warm summer months next year and not while she is still taking care of her current pup, fur seals use a method called delayed implantation. Delayed implantation means the egg is fertilised, but does not implant in the uterine wall for another 3 months. Gestation is therefore about 9 months, even though the female is mated 12 months before she gives birth.
From birth to weaning
Pups are suckled for about 300 days, though some will continue to suckle into their second year.
Females alternate foraging trips (periods of 1 – 20 days at sea) to feed, with attendance periods (1 – 2 days), where they are at the rookery to suckle the pup. As the year goes on and the pups grow, the females take longer and longer foraging trips.
Pups start to feed on solid food before weaning and spend a large proportion of time playing with other pups and objects such as seaweed and reef fish. It is possible that they attain skills for later life (such as foraging, anti-predator behaviour and also social behaviour) during this period.
During spring most pups are weaned and disperse. Juvenile fur seals have been found over 1000 km away from their place of birth!
Human activities are the cause of most threats to kekeno today. It is known that fur seals are incidentally captured and subsequently drown during trawling and long line fishing operations in New Zealand.
The West Coast hoki trawl fishery’s impact on fur seals is the most well understood. Fur seals become entangled in the nets as they are dragged through the water. Devices that block seals from entering these nets, while allowing target species in, are currently being tested by DOC.
Further threats caused by humans include the entanglement in marine debris and harassment by the public.
Great white and sevengill sharks are the main natural predators of seals. New Zealand sea lions may occasionally take juvenile fur seals in the sub-Antarctic islands but this has not been reported in mainland New Zealand. Killer whales (orcas) and leopard seals may also prey on kekeno.