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The
Hector’s dolphin is only found off the coast of New Zealand, which means it is
endemic to New Zealand.
The Hector’s
dolphin is the rarest marine-living dolphin in the world – not a title to envy! |
| A Threatened Species The Hector’s dolphin was given ‘threatened species’ status
by the Minister of Conservation, Sandra Lee, in December 1999.
Under the Marine Mammals Protection
Act, the Minister must improve protection measures for the Hector’s dolphin and see
the population gain ‘non-threatened’ status within 20 years from this date.
The best way to help the
Hector’s dolphin would be to ban gill netting in areas where they live.
All dolphins in New Zealand are
protected by the Marine Mammals Protection Act, which is administered by DOC. To learn
more about it go to www.doc.govt.nz/cons/marine/marine_mammals.htm
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What’s a
dolphin?
- It’s a mammal – they need
air to breathe and their young suckle for milk.
- Dolphins are not porpoises.
- Cetacean - a cetacean is a creature
belonging to a group of water living mammals having no hind limbs and a blowhole for
breathing, including toothed whales, dolphins and porpoises.
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Who’s
Hector ? |
Hector’s dolphin was named after Sir James Hector. Sir James
was the curator of the Colonial Museum in Wellington (now the museum of New Zealand - Te
Papa). He examined the first specimen found of the dolphin. Sir James lived from 1834 to
1907. He was the most influential New Zealand scientist of his time, which means he was
really onto it when it came to science and was really into learning about nature - cool. |
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Is it a Hector’s
dolphin? It may not be easy
to tell which dolphin is ‘flying’ by when you see them from the shore or from a
boat, so here’s some help…
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| The
Hector’s dolphin is much smaller than other dolphins seen in New Zealand waters. An
adult Hector’s dolphin grows to a length of 1.2 to 1.4 metres, compared with 4 metres
for the bottlenose, 3.4 metres for the striped dolphins and the Dusky dolphins 2 metres.
Also, the Hector’s is a little rounder than other New Zealand dolphins. The hector’s does not have a
bottle-shaped snout. The forehead of the Hector’s slopes down to the tip, so it does
not create a protruding beak like the bottlenose dolphin. |
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It has
a small, distinctive, rounded dorsal fin – all other species of dolphin found in New
Zealand waters have crescent shaped fins.
The colour scheme of the
Hector’s dolphin is well defined with areas of grey, black and white.
The sides of the head, the
flippers, dorsal fin and the tail are all black. The belly is white except for a small
area between the flippers. There is also a distinctive finger-like swoosh of white that
extends from the belly, along the flanks towards the tail. The rest of the body is grey. |
| Facts…
The scientific name for the
Hector’s dolphin is Cephalorhynchus hectori
Hector’s dolphins are members
of the family delphinidae, of which there are 32 species worldwide.
The Hector’s dolphin is the
smallest in the family and the smallest sea-living dolphin, as well as the rarest oceanic
species.
Female Hector’s dolphins are
usually 1.2 – 1.4 metres long and weigh about 45 kilograms, males are a little
smaller and weigh about 10 kilograms less than the females.
Of all the dolphins seen in New
Zealand waters, Hector’s dolphins are the only ones with a rounded dorsal fin.
Hector’s dolphins feed on fish
and other sea creatures found in shallow water with a sandy bottom, such as flounder, red
cod, mackerel, crabs and squid.
They use echo-location to locate
their prey – it’s like seeing with sound. Dolphins send out a stream of high
frequency clicking noises and when the sound strikes an object it bounces back and the
dolphin can tell by listening what the object is - what kind of fish it is, how far away
it is and how fast it is moving. That’s pretty clever!
In familiar areas the dolphins will
travel with their echo-location 'turned off'
The Hector’s dolphin was given
‘threatened species’ status by the Department of Conservation in December 1999.
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| North
and South There are only
about 3000 - 4000 South Island Hector’s dolphins.
A small population of Hector’s
dolphins live off the coast of the North Island, mostly between Kawhia and Muriwai. There
are only about 100 North Island Hector’s dolphin.
There are at least three
genetically distinct populations of the dolphin, one on the west coast of the North Island
and in both the west and east coasts of the South Island. The Southland population also
appears to be genetically distinct. |
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There is a genetic
difference between the North Island population and South Island Hector’s dolphins.
Some scientists think that because the difference is so big, the North and South Island
groups should be considered as separate species. Click here to see a large
version of this map |
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Life,
play and babies…
Hector’s dolphins like to have
company. They usually swim in groups of between 2 and 12 dolphins. |
| Hector’s
dolphin tend to hang-out in the same area for many years and sometimes for life. They
spend their days swimming along the coastline, surfacing to breathe, diving to find food
and playing. Dolphins love to
play – and it’s wonderful to watch! Dolphins spend a lot of time playing. They
play in the surf and use leaves and seaweed as toys. They are also interested in human
activity. Dolphins will swim over to investigate people swimming, in kayaks and boats.
They like to swim beside kayaks and in the wake of boats. Hector’s dolphins seldom
jump clear out of the water but when they do their jumps are very high compared to the
long horizontal jumps of many other dolphin species.
Hector’s dolphins mature at
about 8 years old. They live to around 15 to 18 years old.
Females usually have one calf every
two to three years. Hector’s dolphins mate in late spring (New Zealand spring =
September/October/November). The calf is born about a year later. |
| The calves are 50-60cm
at birth and stay close to their mothers who provide them with milk and security until
they are old enough to fend for themselves, usually around one year old. |
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| Dolphins in Danger The greatest danger to Hector’s
dolphins is gill nets.
The North Island population of
Hector’s dolphin could become extinct within just 50 years (from 2000) if people do
not do something to help. Many dolphins are being drowned in gill nets. It would be
wonderful if the government declared the area where the dolphins live as a Marine Mammal
sanctuary like the one around Banks Peninsula in the South Island.
A sanctuary for the dolphins...
In 1984 there was an estimated
population of 740 Hector’s dolphins off the coast of the South Island between Motunau
and Timaru. In 1988 this population had been reduced by about 230 – that’s how
many Hector’s dolphins probably drowned in gill nets!
This news shocked the government
and the Minister of Conservation in 1988, Helen Clark, declared that there would be a
Marine Mammal Sanctuary off the coast of Banks Peninsula.
The sanctuary covers 1170 square
kilometres. Within the area it is illegal for commercial fishers to use gill nets. Amateur
gill netting is banned during summer, when the dolphins are breeding. Regulations were
also introduced on how and where gill nets could be used. For more information about the
regulations, contact the Department of Conservation. |
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The yellow area of the
map is the sanctuary. It extends 4 nautical miles out from the shore. It starts from Sumner Head in the north and
finishes at the southern end of the Rakaia River mouth. |
| This map
is from the book 'Down Under Dolphins. The Story of Hector's Dolphin'. By Stephen Dawson
and Elisabeth Slooten, 1996. |
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Dolphins in Danger
- As well as being in danger from
drowning in gill nets, Hector’s dolphin has a low birth-rate, which means that their
population does not grow quickly.
- Some dolphins are harmed or killed
by reckless boat users who are not careful in dolphin waters.
- Marine pollution is also a danger to
dolphins. They may accidentally eat rubbish, such as plastic bags, or get caught in it.
Polluted waters may also make dolphins sick.
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How can
you help?
- Do not litter – rubbish can
easily make its way to the sea where a dolphin may get tangled in it or mistakenly think
it is food and eat it – Yuk!
- Make sure only water goes down storm
water drains – keep pollutants out of the ocean!
- If you visit the beach and see some
rubbish, please pick it up and put it in the bin so it doesn’t go in the ocean.
- If you are in a boat when you spot
dolphins, slow down and avoid turning suddenly. Never reverse the boat when you are near
dolphins. Do not harass dolphins, if they move away from your boat, please leave them
alone. Accelerate slowly when you are moving away from dolphins.
- Write to the Minister of Fisheries,
tell him why you believe it is important that gill nets be banned from areas where
Hector’s dolphins live.
- If you ever see a dolphin stranded
on the beach call the Department of Conservation. Even if you get to the dolphin too late
and it has died, still call DOC because the dolphin's body may help scientists learn more
about the species.
- And tell a friend to read this web
page – then they will learn how to care for the Hector’s dolphin too!
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Want to know more
about the Hector’s dolphin?
- Check out this great book,
"Down Under Dolphins. The story of Hectors’ Dolphin." By Stephen Dawson and
Elisabeth Slooten. This book has heaps of great information.
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More
Hector's dolphin pages - Map Gill
Nets Resources
The Hector's dolphin
information was written in August 2000. |
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