Habitat destruction is the leading cause for declining populations of species on our planet. Due to human development, industry, and forestry, humans are destroying the habitat of many species at an alarming rate. Consider the bald eagle. The bald eagle population was threatened in the late 60s and early 70s. Thanks to an aggressive bald eagle protection program, bald eagle numbers in the wild have soared as seen in the population graph above. The bald eagle's population very nearly reached extinction. Why did the bald eagle's declining population make it more vulnerable to extinction?