In sum, zoonotic infectious disease emergence can be explained in part as a consequence of the disruption of natural ecological communities, and the breakdown of naturally existing predator-prey, competitive, and host-parasite relationships that tend regulate and stabilize species' abundance. This can occur through the use of non-selective pesticides through changes in land use and land cover that affect the distribution and abundance of species. It should be noted that the disassembly of natural ecological communities that results from habitat fragmentation is a protracted process compared to exponential decay. Depending on the extent of habitat loss and other factors such as the sizes, shapes and spatial relationships of remaining fragments, the process may require decades, centuries or longer as communities 'relax' toward a new equilibrium (36, 43, 44) . It follows that the frequency of disease emergence can be expected to follow a similar path: highest rates at first, followed by gradual decline as an ecosystem 'stabilizes'.