EXECUTIVE SUMMARY (excerpt)
The first Population and Habitat Viability Analysis (PHVA) Workshop for Orangutan (Pongo pygmaeus) was held in Medan, North Sumatra, Indonesia on 18-20 January 1993.  PHVA workshops use computer models (called Vortex) to simulate the deterministic and stochastic, or random, processes that threaten small populations and to explore what effects various management options may produce on the survival of the population. The workshop focused on the status of wild populations of orangutans on Sumatra and Borneo, with major emphasis on the Sumatran population (Pongo pygmaeus abelii).