It is clear from the previous section that populations are constantly changing in size. Population growth describes the change in population size over time. For example, you read that North Pacific humpback whales experienced dramatic declines in population size from commercial whaling, but when hunting was banned, the populations rebounded from 1,400 whales in 1966 to nearly 20,000 in 2006. Measuring how a population changes over time requires following its demography: births, deaths, immigration, and emigration.
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Population size and growth rate are measured by the numbers of births, deaths, and migrants into and out of the population over time.
Population growth can be limited by density-
Life tables help predict how age-