Whales
Whales make up some of the largest animals on Earth. In fact, the largest animal that has ever lived is believed to be the blue whale.
Whales are mammals, and like humans, they have lungs. They breathe through a blow hole, drawing air into their lungs, so even while they may spend all their time in the water, they must come up to the surface in order to breathe. Many species spend time in Antarctica, and Aotearoa New Zealand is fortunate to be on the migration route of several whale species.
Te ao Māori and te whānau puha
Ngā ika a Tangaroa provides a brief introduction to Māori knowledge of tohorā (whales), te whānau puha – the family of animals that expel air – and other children of Tangaroa.
Traditional pātaka kai (storehouses) are often adorned with whale-like designs as a symbol of abundance and wealth for the iwi. A pūrākau about the chief Tinirau and his pet whale Tutunui is one of betrayal, treachery and greed. It also illustrates of the complex relationship Māori have with whales as guardians, friends and food.
Sperm whale fluke
A sperm whale’s fluke, just before it dives deep into the ocean to feed. The flukes are flexible, able to move up and down, helping to propel the whale through the water.
Photo by Bernard Spragg.
Sperm whale (Physeter macrocephalus)
The sperm whale (parāoa) is the largest of the toothed whales, with mature males an average length of 18 m. They have the largest brain of any animal – six times heavier than a human brain. Sperm whales migrate seasonally to feed and breed, but only the females and young live in groups. The males live mostly solitary lives, except during the mating season.
Sperm whales dive for their prey such as squid. They can be under water for over an hour and to 1,000 m deep, though the normal dive is around 35 minutes and 400 m deep. They are often sighted near Kaikōura.
Southern right whale (Eubalaena australis)
The southern right whale (tohoraha) is typically darker in colour with its head often covered with callosities – large, pale coloured growths on their skin, often infested with parasitic worms, whale lice and barnacles. The markings are all unique so these are very useful for researchers as they help identify individual whales.
Southern right whales
Southern right whales (Eubalaena australis) were once common in New Zealand’s waters but came close to extinction after intense hunting. There is still a small population of the whales that visit Port Ross in the Auckland Islands each winter to breed and calve. New Zealand’s southern right whale numbers are slowly recovering, but despite their increasing numbers, the genetic diversity of the population remains low.
Southern right whales are genetically differentiated based on philopatry to their calving grounds (Australia, New Zealand, South Africa or Argentina) but are still considered the same species.
What are the issues associated with a lack of genetic diversity in a species?
Acknowledgement: Sir Peter Blake Trust.
Minke whale
There are two species of minke whale (pakake) – the northern common minke whale (Balaenoptera acutorostrata) and the southern Antarctic minke whale (Balaenoptera bonaerensis). These are second-smallest of the baleen whales and usually live 30–50 years and calve about every 2 years. They feed during the daytime, mostly on krill.
Minke whale in Antarctic waters
Many whale species depend on Antarctic ecosystems for summer feeding and migrate to warmer, lower latitudes for winter breeding. But Antarctic minke whales are resident all year round.
Bryde’s whale (Balaenoptera edeni)
The Bryde’s (pronounced broo-dus) whale is a baleen whale that prefers warmer more temperate oceans, so only makes short seasonal migrations or none at all. In New Zealand, they are usually found year-round in the Hauraki Gulf and are frequently seen off Tiritiri Matangi and Waiheke Islands. Under the New Zealand Threat Classification System, Bryde’s whales are categorised as nationally critical.
There is ongoing debate about the exact number of species due to lack of information and difficulty distinguishing between possible different species, so it is also referred to as the Bryde’s whale complex.
Bryde’s whale
A population of the endangered Bryde’s whale live in the Hauraki Gulf. Anthropogenic noise is an increasing concern for Bryde’s whales, as they communicate by low-frequency sounds.
University of Auckland research is looking into why the anticipated increase in the Bryde’s whale population has not occurred. It has been hypothesised that the whales are going further out in search of prey due to climate change as marine heatwaves disrupt the Hauraki Gulf’s ecosystem.
Beaked whale
These whales are rarely seen and little is known about them due to their reclusive behaviour and usual deep-sea habitat. Unfortunately, most of what is known about these animals is from the examination of stranded whales that have died. Aotearoa New Zealand is fortunate to have about 13 of the 24 known species found here. Their name comes from their dolphin-like beak. Find out more on the Department of Conservation website.
World’s rarest whale washed ashore
A male spade-toothed whale (Mesoplodon traversii) washed ashore in Otago in 2024. This was very important as only six species had been found prior to this discovery. The species is classified as data deficient in the New Zealand Threat Classification System.
Blue whale (Balaenoptera musculus)
These huge animals can grow up to 30 metres long, but what might surprise you is they get to this size on a diet of krill. They take huge mouthfuls of water and krill and, instead of teeth, they have what are called ‘baleen plates’, which act like a sieve, allowing the whale to push the water out of its mouth while keeping the tasty krill inside.
Blue whales
A pair of large blue whales seen in the north of the Ross Sea.
Blue whales tend to travel by themselves or in pairs, but they are able to stay in contact with other whales through loud calls that can be heard around 150 kilometres away. This sound gives the blue whale the honour of not only being the biggest animal in the world, but it is thought also the loudest!
There are two subspecies of blue whales in the southern hemisphere – the blue whale (Balaenoptera musculus intermedia) and the pygmy blue whale (Balaenoptera musculus brevicauda).
Orca or killer whale (Orcinus orca)
Orcas (kākahi) are commonly called whales but they are actually the largest member of the dolphin family. They have distinctive black and white markings, they are commonly seen in videos and are found all over the world. In many ways, they deserve their name of killer whales because they hunt in packs called pods (usually made up of family members) and they are efficient predators that share their kill among the group. Their diet is varied – they eat fish, squid, sharks, seals, penguins and even other whales.
Orcas jumping
Orcas hunt in packs called pods (usually made up of family members), and they are efficient predators that share their kill among the group.
Photo by National Oceanography and Atmospheric Administration (US).
Toothed whales and dolphins like orcas use a special technique called echolocation to find objects and navigate the world. They send out sounds (that sound like clicks and squeaks to us) that bounce back off objects, and the orcas use this information to determine how far away something is or how big it is. In this way, they can swim in the dark and not worry about getting lost!
Humpback whale (Megaptera novaeangliae)
Humpbacks (paikea) are highly vocal and highly social animals. Like the orca, they travel in large groups – for humpbacks, sometimes these pods number up to 200 individuals. The male humpback sings complex songs, sometimes singing for hours at a time. But it’s not always the same song – slowly, over time, the song changes so that, in a few years, it is a completely different song. And despite scientists being interested in how this singing is done, no one is yet sure. Humpbacks have no vocal cords, no air escapes during the singing sessions and their mouths don’t move.
Humpback whale
A humpback whale jumping from the water. Humpback whales are highly vocal and highly social animals. They travel in large groups, sometimes of up to 200 individuals.
Strandings
Stranding, also known as beaching, is a phenomenon in which whales and dolphins strand themselves on land, usually on a beach, and if they cannot be refloated, they usually die. Unfortunately New Zealand has one of the highest rates of whale strandings in the world, averaging about 300 whales and dolphins per year. The Department of Conservation manages strandings and rescues, with the help of local communities, volunteers and organisations like Project Jonah.
Whale stranding
Many volunteers work to keep the body temperature of a group of beached pilot whales from rising at Farewell Spit, in the South Island.
It is still not known why this occurs, though a possible link to the use of mid-frequency active sonar has been suggested. Dr Craig Radford is investigating the impact anthropogenic noise could have on marine animals in the Hauraki Gulf. This is particularly important to assist with the protection of the endangered Bryde’s whale.
In February 2017, New Zealand’s third-largest whale stranding event occurred. Around 650 pilot whales beached themselves at top of the South Island on Farewell Spit, 350 died but the others were either able to swim away or were refloated by volunteers. The largest whale stranding was in 1918 when about 1,000 pilot whales came ashore on the Chatham Islands.
The Department of Conservation manages marine mammal stranding events. Since 1840, there have been over 5,000 recorded strandings of whales and dolphins. The two most common species of whales that strand alone are pygmy sperm whales and beaked whales. When the occasional mass stranding happens, it is usually by long-finned pilot whales – though these are not whales but one of the biggest members of the dolphin family.
Student activities
Constructing this Kiwi Conservation Club taxonomy dial will encourage students to look more closely at the physical characteristics of the different whale families.
Scientists from the Marine Science Department at the University of Otago use an underwater hydrophone to find out more about the lives of sperm whales. Find out more in this article from the Kiwi Conservation Club.
Learn how to draw a Bryde’s whale with Young Ocean Explorers.
Related content
Go here for a short introduction to mātauranga Māori relating to whales tohorā.
Ethics and whaling introduces some of the ethical considerations associated with whaling.
Find out more about New Zealand’s endemic dolphins.
Useful links
Learn more about Te whānau puha – whales on Te Ara – the Encyclopedia of New Zealand website.
Discover move about whales and strandings on the Department of Conservation website.
Project Jonah have a World of Whales educational resource kit that is free for New Zealand schools. Watch this YouTube video to see the kit being used. For further information, including how to order, is here. Project Jonah also has a volunteer schools educator for the Wellington region.
Marine species expert Hannah Hendrik talks whale strandings, post-mortems and crucial data in this podcast from the Department of Conservation.
In this Science on a Napkin video listen to Dr Rochelle Constantine, a marine biologist at University of Auckland, talk about the reason behind the difference in recovery between the Oceania and East Australian humpback whale populations.
Aotearoa New Zealand is a strong advocate for the protection of whales and a founding member of the International Whaling Commission. Read about New Zealand’s stance on protecting whales on the Ministry of Foreign Affairs and Trade | Manatū Aorere website.
The International Whaling Commission has information about a range of whale species on their website.
Whale research
Read about the research being undertaken by the Marine Mammal Ecology Group at University of Auckland.
The University of Otago’s Department of Marine Science also conducts research on marine mammals.
The Cetacean Ecology Research Group, (Massey University, Auckland) has undertaken marine mammal research within and beyond New Zealand waters since 1999.
Read this article from The Conversation: Warming oceans may force New Zealand’s sperm and blue whales to shift to cooler southern waters.
This New Zealand Geographic article has lots of information on Bryde’s whales and also some of the research that has been undertaken around New Zealand on this species.
Find out about the range of research methods used by the New Zealand Whale and Dolphin Trust.
