An ecological island is a term used in

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

, and increasingly in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, to refer to an area of land (not necessarily an actual island) isolated by natural or artificial means from the surrounding land, where a natural micro-habitat exists amidst a larger differing

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

. In

the term is used to refer to one of several types of nationally

protected areas Protected areas or conservation areas are locations which receive protection because of their recognized natural or cultural values. Protected areas are those areas in which human presence or the exploitation of natural resources (e.g. firewoo ...

. In artificial ecological islands (also known as mainland islands): * all non-native species (at least

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

species) have been eradicated, * native species are reintroduced and nurtured, and * the natural or artificial border is maintained to prevent reintroduction of non-native species. The ultimate goal 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: * 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).

Background

The concept of mainland islands was pioneered in

and arose mainly from the particular circumstances of that country's history. For millions of years New Zealand was part of the supercontinent Gondwanaland, which included

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

, and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

, and shared the same

flora Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...

and

fauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

. About 70 million years ago New Zealand became separated, earlier than Australia, South America and Antarctica. About five million years later non-avian

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s became globally

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

leaving the way open to

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s to dominate - except in New Zealand where there were no land mammals (only 3 species of

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

s and seals). In the absence of mammals,

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s 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

s, many birds had no need to fly and many species became flightless. Birds,

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

s, plants,

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s, and bats, all evolved in 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 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 The ecological restoration of islands, or island restoration, is the application of the principles of ecological restoration to islands and island groups. Islands, due to their isolation, are home to many of the world's endemic (ecology), endemic ...

, creating safe havens for the reintroduction of at-risk species, thereby saving them from extinction. 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. Projects that do meet the criteria, or are aiming to, include: * New Zealand ** 1999

Zealandia Zealandia (pronounced ), also known as (Māori language, Māori) or Tasmantis (from Tasman Sea), is an almost entirely submerged continent, submerged mass of continental crust in Oceania that subsided after breaking away from Gondwana 83� ...

** 2004 Tawharanui Open Sanctuary ** 2005 Bushy Park ** 2006 Maungatautari Restoration Project ** 2007 Orokonui Ecosanctuary ** 2009

Glenfern Sanctuary Charitable Trust Glenfern may refer to: * Glenfern, Queensland, Australia, locality near Kilcoy * Glenfern, Tasmania, Australia, locality in the Derwent Valley * Glenfern House in St Kilda East, Victoria, Australia * Glenfern Sanctuary Regional Park in New Zeala ...

** 2011 Shakespear Regional Park ** 2016 Brook Waimārama Sanctuary **Moehau Environment Group * Australia ** 2015 Nangak Tamboree Wildlife Sanctuary

Background

Offshore islands

Fenced enclosures

References

See also