Transcript Tuatara Sphenodon - Nga Manu Nature Reserve

Tuatara
Sphenodon
New Zealand’s Living Fossil
Presentation by Maggie Drews
What does the name mean?
• Tuatara is a Maori word translating to “peaks
on the back,” referring to the spines
• Sphenodon means “wedge toothed,”
indicative of the shape of the large front teeth
The tuatara will
stiffen its spines
when it is
threatened or
trying to attract a
female!
Why are Tuatara so important?
• Tuatara only exist in New Zealand
• Tuatara are the only surviving
reptile from the dinosaur age and
are therefore called a “living fossil”
• Tuatara have many unique
characteristics, such as a “third
eye,” a unique skull and rib structure,
co-habitation with seabirds, long egg
incubation. The sex of the young
tuatara depends on the temperature
during a particular incubation stage
Where do Tuatara live?
Tuatara Habitat
• Habitat: the environment where a species is
naturally found
• The ancient reptile lives on offshore islands in
coastal forests and clearings. Islands include
North Brother Island, Cook Strait, Islands in
Marlborough Sounds, and off the east coast of the
North Island from Northland to Bay of Plenty
• Sub fossils have been found on the mainland,
showing that Tuatara were once widespread until
humans inhabited New Zealand
Where do Tuatara live?
Tuatara Habitat
• Tuatara often, but not
always, share burrows
with nesting seabirds. This
burrow sharing can result
in large male tuatara eating
seabirds
Fairy Prion (above)
• They live in all sorts of
shares a burrow with
humidity and quite dry
Tuatara
climates, especially up
North
What does the Tuatara do?
Niche of the Tuatara
• Niche: the role of an organism within its habitat or
ecological community
• The role of the tuatara
is to feed mainly
nocturnally (at night)
on beetles, wetas (see
left), snails, lizards,
seabird eggs and
chicks. Adult tuatara
will even feed on
young tuatara!
What does the Tuatara do?
Niche of the Tuatara
• During the day tuatara are usually in their burrows
but are occasionally found basking in the sun
• Tuatara are less active in the winter
Tuatara adaptations:
What is an adaptation?
• Tuatara must have certain behaviours and functions
in order to survive. The tuatara has made
adjustments over a long period of time to increase
its chance of survival in the conditions of its
environment
• The tuatara is unique
because it has changed
very little in the
past 200
million
years!
How has the Tuatara
survived?
• While the closest relatives
to the tuatara became
extinct in other parts of the
world, the tuatara survived
because of New Zealand’s
isolation and lack of
• New Zealand broke
mammal predators
apart from
• New Zealand was once part
Gondwanaland (above)
of a huge continent called
80 million years ago,
Gondwanaland along with
before mammalian
S. America, Africa, India
predators had
Australia and Antarctica
evolved.
Tuatara adaptations:
How has the Tuatara survived?
• Bird droppings attract
• Tuatara shares
burrows with seabirds insects which tuatara
will prey upon
such as shearwaters,
• The tuatara does not
petrels,
have a significant
and
impact on the bird
prions
population because
the tuatara only inhabit
• Occasionally
about 20% of bird
the tuatara will
burrows depending on
take advantage of the
the habitat and
birds by feeding on
population density
eggs and chicks
Tuatara adaptations:
How has the Tuatara survived?
• The cold-blooded
reptiles active body
temperature is 10-25
degrees celsius
• Tuatara can hold their
breath for up to one
hour!
Tuatara are one of the
slowest growing and
longest living reptiles
in the world!
Tuatara has one of
the lowest body
temperatures of
any reptile!
• Tuatara have a
slow metabolism
because of their
low body
temperature
Tuatara adaptations:
How has the Tuatara survived?
• Ability to blend
into surroundings
makes the tuatara
hard for predators
to find
Can you see
the tuatara
in this
photo?
• Able to go long
periods of time
without food
• Eyes are able to
focus
independently and
has a “duplex
retina” for day
and night vision
Tuatara adaptations:
Unique Characteristics
• Like lizards, the tail can
regenerate. When the tuatara
is threatened, it can break off
its tail. The tail is left behind
to distract the predator while
the tuatara makes an escape!
• The tuatara
has no earhole
• Male tuatara
have no
external
copulatory
organ
Tuatara adaptations:
Unique Characteristics
• Development of
• No teeth! Instead,
“caruncle,” used by
tuatara have a
the young to break out
serrated jawbone.
of the egg
Once a “tooth” is worn
down, it will not grow • Tuatara ribs are
structured all the way
back
to the pelvic bone
while other reptiles
have ribs which stop at
the lungs
Tuatara adaptations:
Unique Characteristics
• Tuatara cannot see with •
their third eye, but it is
light and heat sensitive.
The structure is almost •
like a functional eye
“Third eye” is visible
for 6 months on newly
hatched tuatara
The eye is evidence of
the evolution that has
taken place in reptiles.
The Tuatara Family: 2 species
• Brothers Island Tuatara
•
Sphenodon guntheri is only
found on North Brother
Island in the Marlborough
Sounds. It has been
reintroduced to some islands,
including Matiu/Somes
•
Island
• Distinguished by genetic
differences
Common Tuatara
Sphenodon punctatus is
found on offshore islands in
the Marlborough Sounds
and off the northeast coast
of the North Island
There are 2 subspecies of
the Common Tuatara: Cook
Strait and Northern
tuatara
The tuatara is the only living member of its
order, Sphenodontia!
Life of the Tuatara
• Tuatara will shed
their skin 1-2 times a
year. The new skin is
more brightly coloured
than the old skin
• Adult tuatara grow
slowly. There is no
significant growth
after turning about 30
years old
Tuatara can live to be
over 100 years old!
Life of the Tuatara: Mating
• Reach sexual maturity
as early as 13 years old
• Long reproductive
cycle. Females can mate
as frequently as every
two years. Frequency
depends on quality and
availability of food.
• Males mate every year
and can mate multiple
times in one mating
season
• Males compete for access
to females at mating time
• Mating occurs in
January-March
Eggs can take 4 years
to develop in the
female. The longest of
any reptile!
Life of the Tuatara:
Reproduction
• The female will dig a
Tuatara have
shallow spot in loose
the longest
soil, up to 13 cm deep
incubation
period of any
• Up to 19 eggs are laid
reptile in the
between October and
world!
1
December and take
year!
1 year to hatch
• The eggs will develop slower or not at all in the
winter months. Growth will stop and then
resume once it warms up! The temperature of
the egg during a particular stage of incubation
determines the sex of the tuatara
Life of the Tuatara:
Young Tuatara
• Young tuatara feed during the
day for protection from
predators, including adult
tuatara!
• Tuatara break through their egg by using a
“caruncle,” an egg breaking tooth
• The caruncle will fall off after a few weeks
• Young tuatara fend for themselves from birth
Tuatara Killers:
Threats to Tuatara
• Invasive pests!
Tuatara aren’t able to
maintain a healthy
population when rats,
cats, dogs, or wild
pigs are present
• Pests alter
habitat,
eat eggs
and tuatara
• Climate change may
affect tuatara because of
their specific temperature
needs. If New Zealand
temperatures rise, the
tuatara may, like its extinct
ancestors, not adapt in
time
• Changing temperatures
may also affect the number
of males born vs. number
of females
Tuatara Population:
A Threatened Species
• An unknown number
• Offshore islands are
of Northern Tuatara
always in danger of
are living on Little
pest introduction,
Barrier Island and
poaching, and fires
islands in the Hauraki
• There are about
Gulf, Northland, Bay
50,000 Cook Strait
of Plenty, and islands
Tuatara mainly living
east of Coromandel
on Stephens Island
Peninsula
and some on the Trios
• There are only approx
Group of Islands in the
400 Brothers Island
Marlborough Sounds
Tuatara
Tuatara Conservation
• Tuatara were fully
protected by law
in 1895
• The Common
Tuatara is
listed as DoC
category 7
range
restricted
• The Brothers Island
Tuatara is listed as
DoC category 2
nationally
endangered .
Details on the DoC
categories can be viewed
on
http://www.doc.govt.nz/te
mplates/MultiPageDocum
entTOC.aspx?id=42704
Tuatara Conservation
• The New Zealand
Department of
Conservation collects
tuatara eggs to raise
captive young. The
young are released at
approx 5 years old
• DoC has reintroduced
tuatara to five offshore
islands: Matiu/Somes,
Whale, Titi,
Ian Weeds of Nga Manu
Whakaterepapanui and
pictured with tuatara that Tiritirimatangi Island
were released in 2004
Tuatara at Nga Manu
• Nga Manu
• Steve is our oldest tuatara.
currently has 8
He was born in 1978, but he’s
tuatara
only been at Nga Manu since
• We have 3
2002
females, 2 males,
and 3 of
unknown gender
• It is hard to
identify their
exact age unless
• Sylvie is our youngest. She
they were born in
was born in 2001 and has been
captivity
with us since 2004
Tuatara at Nga Manu
• In 2004 Nga Manu released 343 Common Tuatara
to Whakaterepapanui Island
Tuatara at Nga Manu
• 150 Brothers Islands Tuatara have been released
from Nga Manu in the early 1990s to several offshore
islands, including 55 to Matiu/Somes Island
• Nga Manu will continue to support Tuatara
recovery program.
• Tuatara are reared in a headstart facility for 5-7
years until they reach a suitable release size
• Nga Manu has received funding from the San Diego
Zoo to build our biggest headstart facility
• Victoria University, Wellington has been our primary
provider of Tuatara reared in captivity
How can I help save Tuatara?
• Volunteer! Check with the • Donations are always
necessary to your
New Zealand Department
favourite tuatara
of Conservation and other
organization. Tuatara
organisations for
research and
opportunities
conservation efforts
are costly
• Vote for conservation!
• Remember, by
• Educate yourself! The
helping tuatara,
more you know, the more
you’ll help preserve
you can help. Pass your
a living fossil!!
knowledge along to others!
References & Works Cited
• http://en.wikipedia.org/wiki/Tuatara
• http://www.kcc.org.nz/animals/tuatara.asp
• http://www.doc.govt.nz/templates/podcover.aspx?i
d=33162
• Sharell, Richard. The Tuatara, Lizards, and Frogs
of New Zealand. Collins: St James’s Place,
London. 1966. pp. 25-34
• Robb, Joan. New Zealand Amphibians and
Reptiles. Collins: Auckland, 1980 pp. 31-38
• http://www.terranature.org/tuatara.htm
• http://www.iucnredlist.org/