Question

Answer the following question.
"The size of a population for any species is not a static parameter." Justify the statement with specific reference to fluctuations in the population density of a region in a given period of time.

Answer 1

The size of a population of any species is not a static parameter. It keeps changing in time, depending on various factors including food availability, predation pressures, and weather. 

The population density in a given period can fluctuate due to the following four factors:

1. Natality: It refers to the number of births during a given period in the population that are added to the initial density.  
2. Mortality: It refers to the number of deaths during a given period that reduced the size.  
3. Immigration: It is the number of individuals of the same species that have come into the habitat from elsewhere during the given period.  
4. Emigration: It is the number of individuals who left the habitat and have gone elsewhere.