(a) : Niche/ecological niche is specific part of habitat occupied by individuals of a species which is circumscribed by its range of tolerance, range of movement, microclimate, type of food and its availability, shelter, type of predator and timing of activity. A habitat has several ecological niches and supports a number of species. An ecological niche is used by a single species. Two or more species cannot use the same niche despite having a mutualistic association. Organisms or populations in competition have a niche overlap of a limited resource for which they compete. Both owl and cat feed on shrews and mice. They occupy the same niche because of being ecological equivalents though their habitats are different.