Why flexible 'specialists' can't be indicator species too

The capacity to shift habitat and diet by such supposed 'specialists' as red colobus makes me question the use of red colobus as indicators of forest health in some regions of Africa. Some primatologists claim that these behavioral adjustments of red colobus are temporary and that what we are seeing is a time lag between response and ultimate population crash. However, in some cases, extinction has long been forecasted and species persist. Many of them persist in altered landscapes - human-induced ecotones. The Zanzibar red colobus is one such species - an exceptional example of a species that ticks many of the vulnerability traits predisposing it to extinction (island endemism, fragmented habitat, persecution, specialized morphology) and yet adapts through innovative, flexible and opportunistic behavior.