Introdctions on species into an ecosystem depends on what ecosystem is
involved. If they are island ecologies, introductions can be devastating.
Also, depends on the size of the ecosytem involved. Hawaii and other islands
in the Pacific are cases in point.



Since Captain Cook's arrival in Hawaii, 25 species of endemic birds alone
have become extinct. The coming of the modern man has been responsible when
he brought cattle, goats. European boar, mongoose, black and brown rats,
sheep, Axis deer, Blacktail deer, feral cats and dogs have all played a
large part. Introduction of the mosquito by whalers in the water casks in
the early 1800's plus introduction of some bird species carrying bird
malaria and other bird diseases which where transferred to endemic birds
played a large part in the extinction of some species of endemic birds.
Research is started to determine whether there is competition between
endemics and introduced birds. There have been 150 different kinds of
foreign birds introduced to Hawaii at one time or the other. Almost all you
see in lowland areas are introduced species. Indian Hill Mynahs, Common
Mynahs, House Sparrows, Zebra Dove, Spotted Dove,Japanese Bush Warbler,
Chukar and would you believe the the Wild Turkey on island of Hawaii.



Large areas of forests and endemic plants were denuded by introduced grazing
animals.

This in turn resulted in the extinction and near extinction of endemic
plants and insects as well as endemic birds. The national park on Hawaii
tried to eliminate goats and cattle there and lo and behold, a few plants
that were thought to be extinct started to make a little comeback. But not
all. I won't get into the ravages of lowland areas by filling, draining, and
drastic alteration of wetlands, marshes and ponds which were responsible for
reducing numbers of waterbirds. Something that we all know is taking place
here on the Mainland.



One needs to examine very thoroughly possible side effects of introductions.
As an example, sugar cane plantations introduced the mongooses to Hawaii to
prey on Black and Brown Rats that were causing considerable damage to sugar
cane. They never thought about the fact that that the mongooses are usually
diurnal and the rats nocturnal. Incidentally, early Polynesians settling in
Hawaii introduced the Polynesian Rat there.



Introduction of Europen hares and rabbits as a source of food for guano
diggers in the early 1900's on 1600 acre Laysan Island in the Northwestern
chain. When guano digging became unprofitable after a few years and the
guano diggers left, rabbits being rabbits, consumed all the vegetation on
the island and three species of landbirds, the flightless Laysan Rail, the
Laysan Honeycreeper and the Laysan Millerbird became extinct. The Laysan
Duck, which occurred only on that island, was reduced to less than 5-6 birds
Some species of seabirds inhabiting the island which nested in burrows were
buried by sands caused by sandstorms

which swept over the island. Also, some species of plants formerly occuring
on Laysan have become extinct. Incidentally, that is one of the reasons why
any landing by people on the Northwestern Hawaiian Islands which islands
comprise the Hawaiian Islands National Wildlife Refuge is by permit ONLY and
clothing and equipment taken ashore is rigorously inspected for possible
introductions of insects, eggs, larvae and weed seeds.



Any and all introductions must be thoroughly researched, I mean thoroughly
researched, for the possibility they could be harmful to existing wildlife,
insects, plants, gastropods, etc.and have drastic effects on existing
ecosystems.



The Brown Tree Snake, introduced accidentally to Guam and Saipan, has just
about exterminated all endemic bird life on those islands. Wildlife
officials in Hawaii and elsewhere prohibit the introduction of all snakes
there, but with the constant transportation by air, shipping and travel by
private yachts it may only time when it is accidentally introduced. Most
accidental introductions in recent times occur on military bases - snakes
being found in the wheel wells of aircraft. Gives Customs, Agricultural and
Wildlife officials gray hairs. One may be surprised by the number of people
ditty bopping around the oceans for pleasure.



Mongooses introduced by sugar planters to combat rats in sugar cane in
Hawaii. One thing they didn't consider was that rats were nocturnal and
mongooses diurnal.



Time to get off my soap box before the rotten tomatoes hit me.



Gene Kridler, Retired USFWS

16 years spent on Hawaii as FWS Wildlife Administrator and Endangered
Species Coordinator for Hawaii, Samoa, and central and west Pacific Islands















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Best Wishes

Steven Mlodinow