Increasing population size reduces available resources limiting population growth. In restricting population growth, a density-dependent factor intensifies as the population size increases, affecting each individual more strongly. Population growth declines because of death rate increase, birth rate decrease or both. There is a reduction in the food supply which restricts reproduction resulting in less offspring. The competition for space to establish territories is a behavioral mechanism that may restrict population growth.
Predators concentrate in areas where there is a high concentration of prey.
As long as the natural resources are available, in sufficient quantity, the population will remain constant. As the population decreases so do the predators. The accumulation of toxic wastes may also limit the size of a population. Intrinsic factors may play a role in limiting a populations size. High densities may cause stress syndromes resulting in hormonal changes that may delay the onset of reproduction.