The shape of pyramids given the reflection of growth status of a population. Identify the growth status depicted by the given pyramid.

Concept:

• A population at any given point of time comprises of individuals of different age groups.
• The percentage of individuals of a given age or age group is known as age distribution, which is an important population attribute.
• Age pyramid is a structure that results from the plotting of the age distribution of a population.
• For a human population, 3 age groups are considered:
  • Pre-reproductive
  • Reproductive
  • Post-reproductive
• The pre-reproductive age group occupies the lowermost layer of the pyramid.
• Thus, a narrow base would indicate low number of young individuals.

Important Points

• The age pyramids usually include both male and female individuals.
• The shape of the pyramid shows the growth status of a population.
• They can be of 3 basic types:
  • Expanding - Pre-reproductive group is maximum and post-reproductive group is minimum.
  • Stable - The pre-reproductive and reproductive groups are almost equal, while the post-reproductive is less.
  • Declining - Pre-reproductive group is lesser than the other age groups.

Hence, the given diagram denotes stable population.