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 A visit to the Lyman Museum: Biogeography
The Hawaiian Islands are 2,500 miles from the nearest landmass. Every plant and animal that arrived here had to go by wind, wave or wing. Once here, many of these life forms developed special adaptations. For example, the first crickets to arrive in Hawaii were adapted to life in the splash zone. As some of these crickets moved out across the island, some specialized in hiding in the cracks of lava flows and others adapted to living in caves. The cave crickets have reduced eyes and are pale in color.
As you travel from mountain top to seashore, Hawaii has a number of life zones, each with its very special life forms that have evolved from mainland varieties. Examples of some of these are as follows:
Alpine:
The silver sword evolved from a mainland tar weed. The wekiu bug (Nysius wekiuicola) has "antifreeze" in
Mamane
its blood which allows it to survive the extreme cold.
Subalpine:
In this dry, cool zone, the Mamane tree (Sophora chysophila) and the
palila (a type of honeycreeper bird) have a symbiotic relationship. The basic food of the palila is mamane seeds, and without the palila, the mamane tree would not be dispersed.
Montane:
The Ohi'a tree of this temperate, dry region
has evolved a different
leaf type from those on the mainland. Since there were originally no herbivorous animals in Hawaii,
many of the plants have lost thorns, strong smells, and poisons that are displayed by their mainland counterparts.
Rain forest:
The happy face spider evolved to thrive in this cool, humid and lush environment.
Lava tube caves:
Cave crickets, cave millipedes, cave centipedes and
Ohia Lehua
cave moths have all evolved in the lava tube cave environment.
Miscellaneous:
In the absence of predators, an endemic species of flightless goose evolved here. They also prefer dry land to water and have lost the webbing from their feet.
Wetlands:
A mallard-like bird has evolved in Hawaii. Since it is closely related to ordinary mallards and could interbreed, no mallards are allowed. Also, fish with fins evolved into suckers so they can climb rocks up waterfalls to lay their eggs are found here.
Sandy Beach:
The Hawksbill turtle is endemic here.
Additional zones with their own special communities of plants and animals include the intertidal zone, the coral reefs and the open ocean.
A total of 185 natural communities can be found in Hawaii. Adaptive radiation is the term used to describe the changes the various organisms underwent to equip them specifically for the natural community in which it lives. The Hawaiian honeycreepers show the greatest adaptive radiation of any other birds on earth, and they all evolved from a single species of finch.
Written By
Ellen Kelley
Images provided by the Bishop Museum
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