Species become rare when disturbances disrupt their natural activities, diseases impact their population, other species begin to replace them in the ecosystem, and/or their homes are destroyed either by natural or unnatural events. Depending on the severity of the impact or disturbance, some species may be able to naturally recover from such events provided they are protected from further impacts until populations rebound. Unfortunately, some species have a harder time rebounding and may become more rare over time because the impacts may have been more severe or possibly irreversible. To prevent an increase in the number of rare species, conserving healthy, native ecological communities is necessary for the preservation of the common species and the protection of the rare.