Parasites A Key To The Decline Of Red Colobus Monkeys In Forest Fragments: "Forest fragmentation threatens biodiversity, often causing declines or local extinctions in a majority of species while enhancing the prospects of a few. A new study from the University of Illinois shows that parasites can play a pivotal role in the decline of species in fragmented forests. This is the first study to look at how forest fragmentation increases the burden of infectious parasites on animals already stressed by disturbances to their habitat."