THE FASCINATING LIFE OF NZ SEA LIONS
Some of the best moments in travel are when you find yourself in a place you hardly knew existed, where few other people have been, seeing something that ONLY exists in this one area in the world. It’s those moments when you realise how truly big and diverse the world really is and how many incredible creatures there are residing in it.
Spotting New Zealand sea lions lazing on the rocky shores of the Auckland Islands is one of those moments. Once found all along New Zealand’s coasts, the New Zealand sea lion was nearly wiped out by hunters looking for their hides and oil in the 19th Century. Now, with a population of around 13,000 (from a count undertaken in 2000), New Zealand sea lion (also known as Hooker’s sea lions and as whakahao (males) or rāpoko (females)) is one of the rarest and most threatened sea lions in the world. You can find them only in the Auckland Islands, Campbell Islands, Otago and more recently on Stewart Island.
Conservationists are working hard to revive the population but there are several challenges. Several hundred sea lions are thought to have been killed by squid trawl fishery. Unfortunately, many of these are females who are nearly always pregnant and likely have a pup on land, meaning the mortality rate could potentially be up to 3 times higher as a result. In 2007, trawlers introduced Sea Lion Exclusion Devices that are meant to force a sea lion out of a trawl net before it drowns. Whilst these devices have an estimated 91% ejection rate, around half the animals that escape have suffered traumatic internal and head injuries, compromising their survival rates.
Regulations that can now see trawlers out of action until the following season if they catch too many sea lions have also been put into place.
Secondly, breeding is relatively slow with a high mortality rate. Males will arrive at the breeding ground in November, staking their claim on a part of the beach and fighting off any other contenders. By the time the females arrive in December, the males have sorted out territory and the winning males will attain a harem of 8-25 females. Females usually return to the same place that they were born year after year, meaning establishing alternative breeding grounds is not as easy as it may sound. Females give birth to one pup and will wean at around 8-10 months. Although born on the beach, after around 6 weeks the mothers may move them into vegetation for their protection for when the mothers go hunting which may be for 2 or 3 days at a time. Aggressive male sea lions can and will kill pups they see as a threat.
Pupping rates have decreased over recent years as a result of females not returning to the breeding site. It’s not known exactly why this is but could be due to the numbers being caught in trawling nets as well as the food supply being diminished by fishing, making foraging difficult for lactating females.
Pups start exploring freshwater pools by 4-6 weeks and then out into the ocean and neighbouring islands at around 3 months.
You can differentiate the males and females easily. When fully grown, males are dark blackish-brown with a mane down to their shoulders, while the females are grey or buff-coloured with a lighter belly. Males are also considerably bigger than females, weighing up to 450kg compared to the females 150kg, and longer in length, growing up to 3.25metres compared to the females who grow up to 2 metres.
Now, how do you see these beautiful creatures? Because of their remote location, the Subantarctic Islands are not just a day trip from New Zealand’s South Island (and it's not just these beautiful sea lions you get to see - check out these other critters that call NZ home). There are also strict conditions on how many vessels can visit the islands in a season. Expedition or luxury expedition cruises operate in the region during the summer months. Often they will combine the Subantarctic Islands with New Zealand’s Milford Sound and generally shore visits and zodiac excursions are included in the price. For example, Ponant Cruises’ luxury expedition ship, Le Laperouse, visits the spectacular Milford and Dusky Sounds before heading out to the Snares, Macquarie, Campbell and Auckland Islands, finishing in New Zealand’s capital, Wellington. On this particular voyage, all meals, beverages, zodiac excursions and guided walks are included in the fare. For more information on this cruise to the Subantarctic Islands, you can view the package and itinerary details here or you can request a call from one of our Ultimate Cruising experts by clicking here.
Image credit Karora [Public domain], from Wikimedia Commons