Estimates are that the Mkomazi Game Reserve in Tanzania would lose 17 of its 39 species of large mammals in the next 300 years if it is separated from surrounding reserves.
Species-area curves can be used to predict how large a reserve must be to preserve its biological diversity.
For the Australian wheatbelt region, estimates are that a reserve of 43,000 hectares would be necessary to preserve all 25 species, and a reserve ¾ that large to preserve 90% of them.
The largest current preserve is 5119 hectares.
Based on work initiated by Terborgh, 5,000 square kilometers has been adopted as a rough minimum size for major tropical forest preserve in the Amazon Basin.
Based on very speculative reasoning, it is thought that this might reduce extinction rates to less than 1%
Near Manaus, Brazil, forest patches have been established: 1, 10, 100, 1,000, and 10,000 hectares.
Censused prior to isolation, and will be studied for at least 20 years.