Question

In the 1930’s and 1940’s a new Whooping Crane breeding ground in Texas was discovered, which contained about 25 Whooping Cranes. Their numbers started to steadily climb in the 1960’s and 70’s. In 1980, there were 75 individuals reported, and by 2000, there were 150 reported. If their population growth continued at the same rate and the population is not limited by any carrying capacity due to the environment, based on the population values in 1980 and 2000, how many Whooping Cranes would you predict to see by 2040?

1,200

75

300

600

225

Answer 1

The right answer is 600.

Explanation: The rate of population increase is 100 % increase every 20 years which means it is doubling every 20 years based on population values in 1980 and 2000.

So to calculate the population multiply the population with 2 for every 20 year passed.

1980: 75 individuals

2000: 150 individuals

2020: 300 individuals

2040: 600 individuals