An Ecological Island is not necessarily an island surrounded by water, but is an area of land, isolated by natural or artificial means from the surrounding land, where:
- a natural micro-habitat exists amidst a larger differing ecosystem,
- all non-native species (at least predator species) have been eradicated,
- native species are reintroduced and nurtured,
- the natural or artificial border is maintained to prevent reintroduction of non-native species. An island (ˈaɪlənd or isle (/ˈaɪl/ is any piece of land that is completely surrounded by water in two dimensions above high tide and isolated from other significant An ecosystem is a natural unit consisting of all plants animals and micro-organisms( Biotic factors in an area functioning together with all of the non-living physical (
In addition, there is usually provision for controlled public access, and scientific study and research.
The ultimate goal is to recreate an ecological microcosm of the country as a whole as it was before human arrival.
The definition does not include land within a fence erected to:
- protect farm animals from wild predators
- protect a specific species from specific predators
- exclude farm animals only
- exclude native animals (although some native animals, weka for example, may need to be excluded during a species' recovery phase)
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Background
The concept was pioneered in New Zealand and arose mainly from the particular circumstances of that country's history. The Weka or woodhen ( Gallirallus australis) is a Flightless bird species of the rail family. New Zealand is an Island country in the south-western Pacific Ocean comprising two main landmasses (the North Island and the South Island For millions of years New Zealand was part of the supercontinent Gondwanaland, which included Australia, Africa, and South America, and shared the same flora and fauna. Gondwana (ɡɒnˈdwɑːnə originally Gondwanaland) was a southern Supercontinent that existed about 500 to 200 Ma ago For a topic outline on this subject see List of basic Australia topics. South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a In Botany, flora ( Plural: floras or florae has two meanings The first meaning flora of an area or of time period, refers to all Fauna is all of the Animal life of any particular region or time About 70 million years ago New Zealand became separated, earlier than Australia, South America and Antarctica. About five million years later 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 Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands Pinnipeds ("fin-feet" lit "winged feet" or fin-footed mammals are a widely distributed and diverse group of semi-aquatic marine Mammals comprising In the absence of mammals, birds became dominant. Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. 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 the absence of mammals, and have little defence against alien species. Reptiles, or members of the class Reptilia are air-breathing Cold-blooded Vertebrates that have skin covered in scales as opposed to hair or feathers Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described
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 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 the mainland because introduced pests could not reach them.
Offshore Islands
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. The Department of Conservation (In Māori, Te Papa Atawhai) commonly known by its acronym " DOC " is the state sector organisation The ecological restoration of islands, or island restoration, is the application of the principles of Ecological restoration to Islands and island groups These islands are also used to expand 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.
Fenced enclosures
Following the example of what had been achieved on offshore islands, groups of New Zealanders decided to create artificial 'ecological islands' on 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'. A pest-exclusion fence is built to exclude certain types of Animal pests from an Enclosure.
Projects that do meet the criteria, or are aiming to, include:
- New Zealand
- Australia
See also
Karori Wildlife Sanctuary is a protected natural area in Wellington, New Zealand, where the bio-diversity of 225 ha (just under a Square mile The Maungatautari Restoration Project is the largest ecological restoration project in New Zealand, involving the total removal of all pest Mammals Orokonui Ecosanctuary, called Te Korowai o Mihiwaka in Māori, is an Ecological island wildlife reserve being developed by the Otago Natural History The biodiversity of New Zealand, a large Pacific Archipelago, is one of the most unusual on Earth, due to its long isolation from other ContinentalDapyx Software network: MP3 Explorer | Ebook Manager | Zenithic