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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.