Integrity of protected areas
Protected areas are rapidly becoming isolated, yet the long term viability of these protected areas depends on watersheds outside the protected area, on the ability of animals to disperse and return to the area on an annual basis, and on a flow of animals from other protected areas.
The Tanzanian people depend increasingly on protected areas for the ecosystem services they provide, such as clean and abundant water, hydroelectricity, revenues from tourism, and traditional and future medical products. Wildlife corridors are therefore critically important for ensuring the long term health of the nation’s protected ecosystems.
Increase agricultural yield
Wisely set-aside and well managed corridors can reduce human-wildlife conflict including crop-raiding, and thus increase agricultural yield over the long-term.
Immigration to prevent extinctions
If an animal or plant population declines to low levels or becomes extinct in one area or habitat patch, individuals from another patch can immigrate and rescue that population from local extinction.
Deepen gene pools
If a small population is isolated, it will lose genetic variation over the long term and suffer from inbreeding. A corridor allows immigrants to import new genetic variation into isolated populations.
If the habitat of one area becomes unsuitable (e.g. because of climate change), organisms (both plants and animals) can move along corridors to reach more suitable habitat, and thus be ‘rescued’.
Inadequacy of protected area system for conserving species and habitats
Some protected areas, designed decades ago for varying reasons, do not encompass the range of ecosystem requirements needed by certain flora and fauna. Migrating species, for example, especially large mammalian herbivores and associated carnivores, move outside and/or between protected areas. They may also use corridors as dispersal areas.