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18. Be able to identify the different age pyramids: expanding, declining and stable population.

click on image for Labels.

A. Stable Population: the largest numbers are at the bottom and as you compare the older age groups there are gradually fewer individuals. This is a natural progression.

B. Declining Population: Note that the older ages were more successful than the more recent individuals. This population is in trouble.

C. Expanding Population: The youngest individuals at the base are increasing in numbers. Some limiting factor has been removed and the population is responding with greater success at survival.