Download Central Otago`s unique plants and animals

Central Otago’s unique
plants and animals
Otago
Many of the plants and animals that inhabit Central Otago are completely unique and occur nowhere else in
the world. The distinctiveness of much of Central Otago’s native biodiversity means that it cannot be conserved
anywhere else, yet the existing species represent a flora and fauna now much reduced as a result of changes
to the landscape from European agricultural practices. For the following species, it is a race against time for
scientists to learn more about them before they are too rare to be able to be saved
Dryland Central Otago
Dryland short tussock
M. Sole
Otago Conservancy
Published by
Department of Conservation
Christchurch
2006
RS0068
The inland slopes and basins of the Central Otago
drylands are in the rain-shadow of the Southern Alps
and thus experience very low rainfall (around 350
mm per year). Prior to human settlement, much of
this area would have been forested. Both natural
and human-induced fires reduced this forest so that
when Europeans arrived in New Zealand, tussock
grasslands covered two-thirds of Otago. Today only
13% of these grasslands remain.
Healthy dryland short tussock communities contain
as many and more different life-forms as a forest, but
on a much smaller scale. For example, in the Flat Top
Hill Conservation Area near Alexandra, scientists have
recorded over 180 native species.These include small
pockets of saline plants and spring annuals and larger
areas of regenerating native shrubland.
Theses dryland sites are vulnerable to invasion by
exotic weeds such as thyme and hieracium that are
well adapted to the harsh conditions of Central Otago.
The diversity and abundance of native plants and
animals often declines when exotic plants dominate
in this environment. Regeneration projects are a
means to restoring and retaining these threatened
communities.
Cromwell chafer beetle and
Central Otago ground weta
Chafer beetle
Chafers are chunky, flightless, nocturnal, light brown
beetles the size of your thumbnail. Seventeen species
of chafer beetle live only in the Mackenzie Country,
and at least five of these species live only in the
valley floors of Central Otago. The most well-known
of these is the Cromwell chafer beetle, which was
first discovered in 1903 in the sand dunes around
Cromwell. It is now mostly restricted to just 81
hectares of reserve on the southwest side of Cromwell,
and the total population is estimated at no more than
1000 beetles.
The Cromwell chafer beetle is adapted to a special
inland dune habitat, which is also home to a number
of other unusual plants and animals. One of these is
the Central Otago ground weta, which lives in sealed
burrows dug into sandy soil.
The sand-dune habitat where these invertebrates
live would have once been highly mobile and everchanging, conditions which favoured resident plants
and animals. Over the last 50–60 years, the planting
of lupins, marram grass and silver tussock and radiata
pine shelter belts have changed this dynamic dune
system into a stable one, which has helped introduced
plants to spread at the expense of native species.
Inland Lepidium plants
New Zealand has eight
native Lepidium species,
two of which are found
only in very small, dry
parts of Central Otago
and inland Canterbury.
Lepidium are small and
difficult-to-find members
of the cress family. They
are adapted to salty
and arid soil conditions,
and they tend to grow in
areas where few other
plants can survive.
All inland native
Lepidium are
threatened – some critically endangered – and are
only represented by small, isolated populations.
Without effective management, it is likely that some will
become extinct within a decade
Sigaus grasshoppers
Sigaus are a group of grasshoppers that are found
only in a few areas of the South Island. Sigaus
grasshoppers are unique because of their ability to
cope with extreme conditions and in habitats with very
little cover. Sigaus childi is found only in five sites in
Central Otago. Two other species are also present. All
sites are localised, harsh dry environments.
Relatively little is known about Sigaus grasshoppers,
and unless this lack is redressed, it is possible that
wild populations may collapse before enough is known
to protect them.
Skinks of Central Otago
Several skink species are found only in Central Otago.
The critically endangered Otago skink is the South
Island’s largest skink, and is found only amongst
rocky outcrops in tussock grassland. It has distinctive
golden or greenish patches on its back, sides and tail.
Otago skink M. Aviss
The grand skink is also critically endangered and lives
in deeply creviced schist rock outcrops. DOC has
recently found that both the Otago and grand skinks
may be perilously close to extinction. Other endemic
Central Otago skinks include the scree skink, the
green skink and the cryptic skink.
How can you help?
Community involvement is important for the survival of
Central Otago’s unique plants and animals. You can
help by:
•
Learning more about these special creatures at
your local DOC office or by visiting www.doc.govt.
nz.
•
•
•
Getting involved in field days.
•
•
•
Sharing with others what you’ve learned and seen.
Controlling domestic animals and stock.
Reporting any sightings of rare plants and animals
to the Department of Conservation.
Protecting significant areas on your property.
Taking care to leave habitats as you find them.
Further information
For more information contact the DOC Central Otago
office (Dunstan Rd, Alexandra, Phone 03 440 2040,
Fax 03440 2041) or visit www.doc.govt.nz.