Answer:
When demographers attempt to forecast changes in the size of a population, they typically focus on four main factors: fertility rates, mortality rates (life expectancy), the initial age profile of the population (whether it is relatively old or relatively young to begin with) and migration.
Step-by-step explanation:
In the natural world, limiting factors like the availability of food, water, shelter and space can change animal and plant populations. Other limiting factors, like competition for resources, predation and disease can also impact populations.