List and explain any two factors that lead to a decrease in the population density of an area.

The correct answer is:
• Mortality/Death rate, the number of deaths in a given population during a given period.
• Emigration, the number of individuals who have left the habitat and gone elsewhere during the time period under consideration.

Population density refers to the number of individuals of a species per unit area or volume. The size and density of any population are dynamic and fluctuate based on four primary demographic factors: natality (birth rate), mortality (death rate), immigration (incoming movement), and emigration (outgoing movement).

To understand why the population density of an area decreases, we look at the processes that remove individuals from the population:

1. Mortality (Death Rate): This represents the loss of individuals due to death resulting from aging, disease, predation, resource competition, or environmental hazards during a specific timeframe. As individuals die, the total number of organisms in the habitat declines, thereby decreasing the overall population density.

2. Emigration: This refers to the outward movement of individuals from their native habitat to another geographical area, often in search of better resources, mating opportunities, or more favorable climatic conditions. When individuals leave, they subtract from the local count, directly reducing the population density in their original habitat.