Diversity In Biodiversity

2.1 Biodiversity Biodiversity is often defined as variation of life at all levels of biological components includes diversity within species, among species and comparative diversity among ecosystems (10). It is divided into three levels as follow (11): 1. Genetic diversity – a variety of genes within species, both among separate population and individuals within single population. 2. Species diversity – a variety of organism in ecosystem 3. Ecosystem diversity - variability of habitat and level of organizations with the variation of ecosystem on the earth.

2.2 Bird Diversity A Guide to the Birds of Thailand (12) has indicated the finding of 915 species of bird in 1990 of which 2 species, White eyed–river Martin (Pseudochelidon sirintarae) and Deignan’s Martin (Stachyris rodolphei) are endemic in Thailand (13). The publication has also suggested that 62 additional bird species may be found in the future since these species have already been recorded in neighbor countries. The prediction made in the book is proved that it is

The flying capability is very beneficial to them as an advantage more than other vertebrates. While other animals need to encounter with the difficulty to survive in the environment which are not suitable .When the environment and the habitat are not suitable for living and reproduction, other animals encounter with the difficulty to survive in such environment, while birds can find new and more suitable habitats because of their flying ability. The birds fly over the oceans, mountains or fly to find food resources anywhere they want. The birds can choose a place to nest and raise young birds. The birds are a group of vertebrates that have been very successful in life on land. Compared with other vertebrates, the researchers found that the number of bird species is more, which is about 9040 species (16) and in Thailand with up to 1,018 species