Answer: Immigration can be a reason for a overall increase in the population of a species. It is a method by which the species at other place migrate to a different place permanently. The reason to migrate to a different area can be lack of resources, hunting, or any natural calamities. The population of a particular geographical area shifts to another area only because of the problems that does not allows the population to reside there. This makes the population move to another area for their survival.
