Conservation & Biodiversity
It is sometimes argued that wild animals have lived together for thousands of years without general loss of biodiversity or the extinction of individual species. But this happy state has been irretrievably lost as man has changed the environment in which all species live. The changes have included removal of apex predators, introduction of alien species to habitats where life has evolved without them, loss and degradation of habitats, fragmentation of habitats, over-fishing, and pollution, including that from light, insecticides and herbicides.
In these circumstances, some predators which might, in the past, have posed no threat to the survival of a particular species, have become an important one now. A good example is the threat of badgers to the hedgehog in the UK. This, and other examples, are discussed below.