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14-556: Te Papanui Conservation Park is a mainland island in the Otago Region of New Zealand . It is managed by the Department of Conservation , and opened in its current form in March 2003. This Otago geography article is a stub . You can help Misplaced Pages by expanding it . Mainland island In artificial ecological islands (also known as mainland islands ): The ultimate goal

28-427: A fence's height, depth under the ground and mesh size. It is also important to choose a construction material that cannot be climbed; furthermore, sometimes it is necessary to create a subsurface fencing element to prevent burrowing under the fence. Fences are usually designed with the target pest species (the species to be excluded) in mind, and the fences are made to effectively exclude those species. This results in

42-540: A wide variety of designs for pest exclusion fences (see examples below). Often the fence is encircled in electric wire to ensure that animals can not climb over the fence. Australia has utilised exclusion fencing since the 1860s. The most well known exclusion fences in Australia are the barrier fences. Barrier fences are long (usually linear) barriers erected for the purpose of excluding particular species from large portions of Australia. The most well known barrier fences are

56-615: Is Arid Recovery in South Australia, where feral cat , red fox and rabbit have been removed for the conservation of 5 threatened species. Prior to human settlement New Zealand had no land-based mammals apart from three bat species. The introduced mammal species, such as rabbits, deer, and possum, have since caused huge ecological changes to the biota of New Zealand. Pest-exclusion fences are increasingly used for conservation of indigenous species by excluding all mammals. Locations of predator-proof fences include: Deer-proof fencing

70-498: Is a barrier that is built to exclude certain types of animal pests from an enclosure . This may be to protect plants in horticulture , preserve grassland for grazing animals, separate species carrying diseases ( vector species ) from livestock, prevent troublesome species entering roadways, or to protect endemic species in nature reserves . These fences are not necessarily traditional wire barriers, but may also include barriers of sound, or smell. Animals can be excluded by

84-485: Is to recreate an ecological microcosm of the country as a whole as it was before human arrival. There is usually provision for controlled public access, and scientific study and research. The definition does not include land within a fence erected to: The concept of mainland islands was pioneered in New Zealand and arose mainly from the particular circumstances of that country's history. For millions of years New Zealand

98-691: The Dingo Fence and the Rabbit-proof fence , but there are many others. In more recent years, pest-exclusion fences have been built around singular properties, or groups of properties. This practice is known as cluster fencing. Cluster fencing allows farmers to monitor and mitigate predation pressure on livestock , and monitor Total Grazing Pressure (TGP) through accurate abundance data of native, pest, and domestic herbivores . Australia uses pest-exclusion fencing to separate several high-value or threatened species from introduced predators. One such example

112-445: The absence of mammals, birds became dominant. Evolutionary processes resulted in a unique assemblage of plants and animals, and New Zealand became a land dominated by birds. Without competition from browsing mammals, birds evolved to occupy niches that mammals occupied elsewhere. Threatened by few predators , many birds had no need to fly and many species became flightless. Birds, reptiles , plants, insects , and bats, all evolved in

126-498: The absence of terrestrial mammals, and have little defence against alien species. With human colonisation came many accidental or deliberate introductions of mammals and birds. These wrought havoc with native species and many became extinct, many others were reduced in range and number, with some teetering on extinction. Traditionally pacific rats ( Rattus exulans ), Norway rats ( Rattus norveigucus ), ship rats ( Rattus rattus ) cats, ferrets, stoats, and weasels were all considered to be

140-486: The main culprits in the decline of native species of New Zealand birds, reptiles and insects. More recent information adds hedgehogs and mice to the list. These species have been introduced for a variety of reasons and some inadvertently. The effect remains the same: they have all contributed to the decline of native animals. Possums and deer did the same for the forest. However, New Zealand also includes many offshore islands, some of which contained species rare or extinct on

154-450: The mainland because introduced pests could not reach them. Increasingly over the last hundred years, New Zealand's Department of Conservation together with many volunteers have developed and perfected world-first methods of clearing some of these islands of all introduced pests, and island restoration , creating safe havens for the reintroduction of at-risk species, thereby saving them from extinction. These islands are also used to expand

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168-465: The mainland so that the public could have easier access and learn what New Zealand looked and sounded like before human colonisation. There are excellent projects where alien species numbers are kept down by various methods other than a pest-exclusion fence or the coastline, but these are not generally described as ecological islands. Projects that do meet the criteria, or are aiming to, include: Pest-exclusion fence A pest-exclusion fence

182-494: The range of rare species so that an ecological disaster on one island would not result in the total extinction of a species. As many species rebound in numbers in the absence of predators the islands act as species reservoirs enabling the periodic removal of some to create breeding colonies on other cleared islands, or on the mainland itself. Following the example of what had been achieved on offshore islands, groups of New Zealanders decided to create artificial ecological islands on

196-538: Was part of the supercontinent Gondwanaland , which included Australia , Africa , and South America , and shared the same flora and fauna . About 70 million years ago New Zealand became separated, earlier than Australia, South America and Antarctica. About five million years later non-avian dinosaurs became globally extinct leaving the way open to mammals to dominate - except in New Zealand where there were no land mammals (only 3 species of bats and seals ). In

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