One of the needs of this Internet version is to encourage the compilation of knowledge to fill in the gaps on this listing. Similarly, some fieldshave been included within the database for which information do not usually exist, but which would be very useful for comparing islands or for responding to explicit problems. Again it is hoped this can stimulate people to gather such information.
The isolation of many islands might defend some animals on them from predators and other dangers that exist on mainlands. Relatives of some animals lengthy extinct in most components of the world still survive on islands. The isolated populations on islands can result in smaller, in addition to bigger, species. The critically endangered Sumatran tiger is simply found on the island of Sumatra, Indonesia. It is significantly smaller than its Asian cousins, as a result of it has less land to roam, smaller prey to feed on, and should move quickly in the jungle. Also on the Galapagos Islands, big tortoises developed from smaller ancestors over hundreds of thousands of years. Scientists consider the first tortoises in all probability came to the islands from South America on floating islands.