I. THE EASTERN VISAYAS BIO-GEOGRAPHIC ZONE

The Philippines is divided into several bio-geographic zones based on its floral, faunal and geological composition.  The island of Samar is part of the Eastern Visayas Bio-Geographic Zone (EVBZ) and the Greater Mindanao Faunal Region (GMFR).  It is considered as one of the centers of the botanical diversity of the Philippines, and shares strong floristic affinities with Leyte, Luzon and Northeastern Mindanao Islands. This floristic relationship can be attributed to the geological history of these islands.

Samar and Leyte were one landmass since the late Cenozoic period.  During the Miocene upheaval, the Samar-Leyte landmass was connected to Sorsogon in the north and Surigao del Norte through Dinagat Island in the south.  Luzon was separated from this large landmass during the Pliocene period.  When the sea receded during the Pleistocene period, Samar-Leyte-Northeastern Mindanao was rejoined to Luzon and also with Bohol.  These land connections were then broken during the post Pleistocene period resulting to independent islands of Samar, Leyte, Luzon, Bohol, Dinagat and Mindanao.  This is precisely the reason why some islands share the same species composition although to some extent there are also island-restricted species.

Several species are unique to EVBZ including certain species that only exist in Samar Island while some species can also be found in the neighboring landmasses of Bicol, Eastern Mindanao, Dinagat and Siargao.  Majority of the region’s fauna are shared with Mindanao because its northernmost section is part of GMFR.

II. SAMAR AS NATIONAL AND GLOBAL CONSERVATION PRIORITY

The World Wildlife Fund (WWF) declared the island of Samar as one of the 200 Eco-Regions of the world.  An eco-region is characterized by its high biodiversity and rate of endemism, which are vital to the preservation of the Earth’s biodiversity.  Similarly, Samar Island is identified by the Birdlife International as one of the nine Endemic Bird Areas (EBAs) of the Philippines.    Jointly with the Birdlife, the Haribon Foundation for the Conservation of Natural Resources (HARIBON) included several areas of Samar Island in the 118 Important Bird Areas (IBAs) and key conservation sites of the Philippines.  It is also one of the 18 centers for plant diversity of the country.  The Foundation for Philippine Environment (FPE) has also prioritized the island for its funding support.

The Conservation International (CI) considers Samar Island as one of the 206-biodiversity conservation priority areas of the Philippines.  The island is extremely high in biological importance on terrestrial and inland water areas and known as an important biodiversity corridor of the country.  It is also extremely important as a priority area for the conservation of plants, amphibians, reptiles, birds and terrestrial mammals.