Get to know: marine mammals

Department of Conservation —  17/12/2020 — 2 Comments

Nearly half of the world’s dolphins and whales (cetacean species) spend their time in New Zealand’s oceans. At least 26 species of whale and 15 species of dolphins can be spotted here. Here are some identification tricks to keep up you’re sleeve, if you’re fortunate enough to catch a glimpse of one!

Bottlenose Dolphin

Bottlenose dolphins / terehu are easily identified by their short beak and hooked dorsal fin. They can be seen all around the New Zealand coast.

Illustration of bottlenose dolphin / terehu. Status: threatened (nationally endangered). Identification notes: hooked dorsal fin, lighter belly, domed head and short beak. Size up to 3.4m. Found all over New Zealand)Other dolphin species: orca, common dolphin, Hector’s dolphin, Māui dolphin, dusky dolphin, pilot whale.

Common and Dusky dolphins

Other species of dolphins include dusky, Hector’s and Māui, the common dolphin, orca (killer whale), and the misleadingly named pilot whale.

Common dolphins have a distinct ‘hourglass’ pattern on their sides, below the dorsal fin. They can live in pods of up to 1000 individuals.

Dusky are easily identified by their sloping forehead and dramatic contouring. Duskies are considered to be one of the most acrobatic dolphin species and will live for over 30 years.

The common dolphin (top) and the dusky dolphin (below) appear quite similar – but the differences in their foreheads and beaks make for easy identification. 📷: Callum Lilley (top) and Shellie Evans (below)

Hector’s and Māui dolphins

Hector’s and Māui are impossible to tell apart without DNA testing, but both are recognisable by their rounded, “Mickey Mouse” dorsal fin. They are the smallest species of dolphin in the world and are found only in New Zealand.

A pod of Hector’s dolphins with their distinctive rounded dorsal fin.
📷 Dina Engel and Andrea Maecker.

Pilot whales and orcas

Pilot whales (the dolphins) are often mistaken for orcas (also known as killer whales – coincidentally, also dolphins rather than whales). Pilot whales have a large, bulbous forehead and light grey or white streak behind their eyes that resemble angry eyebrows.

Top: pilot whale. Look at that glorious, bulbous forehead.
📷: Phillip O’Sullivan.
Lower: orca.
📷: Richard Kinsey.

Humpback whale

As for whales that are actually whales, there are five main types found in New Zealand’s waters: blues, humpbacks, southern right whales, Bryde’s, and sperm whales. The humpback whale is probably the easiest to identify of the lot, with their knobby heads and extremely long flippers:

Illustration of humpback whale / tohorā. Status: non-resident native (migrant). Identification notes: stubby dorsal fin, black/grey with white underside, knobbly protrusions, long flippers. Size 12 – 16 m. Found all over New Zealand. All whales are protected in New Zealand waters.

Other whale species: Southern right whale, blue whale, Bryde’s whale, Arnoux’s whale.

Southern right whale

But how to tell a sperm whale from a blue whale from a Southern right whale?

If it’s got wrinkly skin and a square face, it’s likely a sperm whale. Blue whales have a small, pointed dorsal fin well at the back of their body. No dorsal fin? It’s likely a Southern right whale. They’re identifiable by the calloused white patches on their faces which are actually colonies of whale lice. While that might sound unpleasant, there is no evidence so far that these lice are harming the whales. The lucky lice get a home and a free ride all over the southern oceans.

The southern right whale is returning to the mainland coast after being hunted nearly to extinction.
📷: Finlay Cox/DOC

There are many more species of whales to learn to identify, but don’t despair – there’s a quick guide available on our Whale and dolphin sighting report.

Seals and sea lions

Pinnipeds include seals and sea lions. Aotearoa have four main species of pinnipeds: the New Zealand fur seal, leopard seal, elephant seal, and seal lion. Kekeno / New Zealand fur seal are the most likely to be spotted around our coasts. 

Kekeno were once on the brink of extinction. In 1978, they were given full protection under the Marine Mammals Protection Act, and now can be seen on rocky shores around the country.

Illustration of New Zealand fur seal / kekeno. Status: Not threatened. Identification notes: Pointed nose, long whiskers (past the ears). Size 1.5-2.5 m. Found all over New Zealand. Other seal species: New Zealand sea lion.

Leopard seals / pakaka are easily identified by their leopard-like spots, large heads, slim bodies, and fantastic smiles.

Illustration Leopard seal / pakaka. Status: At risk (naturally uncommon). Identification notes: Leopard-like spots, light grey belly and throat, large head and jaws. Size 3-4 m. Found all over New Zealand.

New Zealand sea lions / pakake can sometimes be confused with a fur seal. Key things to remember: they are typically larger, chunkier, and have short whiskers.

New Zealand sea lion. Status: Threatened (Nationally Vulnerable). Identification notes: Blunt nose, short whiskers. Males brown to black body, females creamy grey. Size 1.6 – 3.5 m. Found in the southern South Island.

The Southern elephant seal / ihupuku is sometimes mistaken for the NZ sea lion. A notable feature is their inflatable proboscus (snout). They are the largest of all pinnipeds, and the second largest marine mammal. Males of this species can reach up to 3,600 kg.

Southern elephant seal. Status: Threatened (Nationally Critical). Identification notes: Inflatable snout and large lower teeth. Size 2 – 5 m. Found in the southern South Island.


We want to hear about any marine mammal sightings you have while enjoying the ocean this summer.

Please visit https://www.doc.govt.nz/nature/native-animals/marine-mammals/marine-mammal-sightings/ to learn how to identify an animal and report a sighting.

DOC has guides for identifying protected species on our Resources for Fishers page.

Marine mammal identification guide

2 responses to Get to know: marine mammals

  1. 
    Katherine Yvonne Lucas 08/01/2021 at 7:18 am

    Thank you. That is really interesting.

  2. 

    Wonderfully informative article

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