Determining Rarity

The issue of whether a species of animal is rare or threatened in an area is less straightforward than it is with plants. The principal reason for this difficulty is simply that most animals can move - sometimes long distances - whereas plants cannot. That means animals can be found in unusual places without it meaning they belong there and also that animals can move from places under threat to more suitable environments. This may seem to be painfully obvious to everyone but how this fundamental difference between the organisms affects their apparent conservation status is a little more complicated.

For example, if a native plant is found in a very few places in Victoria it can reasonably be regarded as rare, and if it is uncommon in most of these places, or the places it grows are subject to threatening processes, such as grazing, mining, building or logging, then it is usually classified as threatened and managed accordingly. Conversely, if a plant, which is not native to Victoria, turns up in a native ecosystem somewhere well away from the state borders, then it is usually assumed to be an alien (which has been transported with human assistance) and steps will often be taken to eradicate it. With animals, however, the story is not always that simple.