Traditional forest reserves are protected natural forests established by ancestors to perform many socio-cultural functions and are protected in accordance to customary laws, not based on government legislation. These reserves generally have a long history with well preserved forests that could demonstrate what the surrounding environment could have looked liked, if humans had not altered it. Therefore, the traditional forest reserves might have significant ecological value and a potential high biodiversity. During February and March of 2009 a field study with semi-structured interviews and field observations was carried out in Babati District in Manyara Region in Tanzania, to study the possible contribution TFRs might have to conservation. The information collected were then analysed using Metapopulation Theory, Island Biogeography Theory and local knowledge concepts. The analysis indicates that there is a higher biodiversity in TFRs compared to surrounding areas and unprotected forests as a result of a rigid traditional protection that local people respect. Further on the MPT and IBT show how TFRs could benefit conservation as islands of refuge for threatened species or as migration corridors between nearby forest reserves and national parks. The future for TFRs and possible conversion into CBFM must include respect and support for the local beliefs as a basis for protection and thereby conservation.