Why do death rates and birth rates fall?
Birth rates and death rates may fall due to: 1) Density Dependent factors – disease, competition, parasitism, carrying capacity, etc. Disease tends to spread faster in highly populated areas. Parasites like ticks and other bloodsuckers also tend to spread faster in highly populated areas. Competition for food may be a problem for animals if there are too much of them looking for the same food. When a population reaches carrying capacity, it cannot grow for much longer so lots of deaths occur, increasing death rate. 2) Density Independent factors – seasonal changes, natural disasters. A rough winter, for example may increase deaths and contribute to a faster death rate.
