Facts about New Zealand fur seal
Introduction
The New Zealand fur seal displays many unique features including its size, range, diet and life cycle.Features
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. Fur seals are usually found on rocky shorelines and 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.
Range
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 sometimes seen north of Auckland.
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.
- Diet of New Zealand fur seals: a summary (PDF, 205K)
- Diet of New Zealand fur seals at Tonga Island, Abel Tasman National Park (PDF, 155K)
Dive patterns reflect the movement patterns of their prey
New Zealand fur seals' prey stay very deep underwater during the day, and then come closer to the surface at night. 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.
Life history
New Zealand fur seal/kekeno spend a lot of their time hauled out on rocky shores, at both breeding colonies and non-breeding ‘haul-outs’. Every year, these sociable animals return to the same area for the breeding season.
Breeding colonies can get noisy. Fur seals make calls for many reasons. For example, males use vocalisations during threat displays, and females vocalise to find their pup when returning after a foraging trip.
Sound clip
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 occasionally calling.
Maturity
Females will have their first 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.
Breeding season
The breeding season takes place from mid-November to mid-January. During this time, females give birth to their pups and then mate.
Dominant bulls put on displays of glaring and posturing and fighting with other males just before the breeding season to gain territories. Fur seals are polygamous breeders – a male may mate with many females in a single breeding season.
Females mate 6-8 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 breeding colony 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.
Posters
Follow the journey of fur seal pups from birth to weaning with these posters: