In the Garden of Eden
The Hawaiian Islands are home to thousands of plant and animal species on land and in water. The history of life in the islands is dramatic indeed, and every kind of creature that comes and goes makes its own small impact. The process took millions of years to transform from bare volcanic landmasses to the verdant, rich environment seen nearly everywhere today. Things changed dramatically, of course, when humans entered the picture. Today, Hawaii can be seen as a veritable paradise or an artificially induced ecological disaster (or a combination of both), depending on your view of things.
The field of island biogeography is fascinating. Among the subjects explored are the questions of how plants and animals came to establish themselves in the middle of the ocean and how they may have changed or adapted over time. How was it all possible? Biologists recognize a number of processes of natural colonization.
The wind can disperse plant pollen and light seeds, which can travel aloft and be carried for long distances. Some plants can actually survive for a bit at sea and be washed up on a beach to establish themselves in a new land. And birds can actually play a very important role in the process. Pollen in seeds clinging to feathers or muddy feet can travel with the help of avian island visitors. Seeds ingested by birds and then later “deposited” elsewhere is also an effective mechanism.
A Nice Home
With increasing favorable conditions, birds themselves started making Hawaii a more permanent home and after millennia of adaptations, new species emerged that are unique to the islands. In fact, Hawaii is home to thousands of endemic species that aren't found anywhere else. These include more than 1,000 different kinds of plants, 5,000 insect species, and more than 800 types of land and freshwater snails. There are also (or, in some cases, were) unique birds, including the beautiful finches known as honeycreepers. The Hawaiian state bird is a goose known as the neneunique to the Hawaiian Islands.
It is much more difficult for mammals to colonize remote oceanic islands, but Hawaii is nonetheless home to a unique bat as well as the Hawaiian monk seal. Off the coasts, there are many endemic species of fish, coral, and shellfish. Of course, these unique species coexist with many life forms that haven't changed since their arrival in the islands. The natural process of island colonization is a dynamic one. Some species survive, some adapt, but many simply won't fit the bill. These do not take hold in the new land.
Species that were on the islands before human colonization are native species, because they were not introduced to the island artificially. Of these, endemic species are those that are unique to Hawaii.