In an area where DDT had been used extensively, the population of birds declined significantly because

Step-by-step solution

DDT, its breakdown products and other chlorinated hydrocarbon pesticides posed an insidious threat to birds. These persistant poisons enter the food chain and they accumulate in the fatty tissues of organisms at lower trophic level and then tend to concentrate as they move through the food chain. This is called biomagnification or bioconcentration. The insidious aspect of this phenomenon is that large concentrations of chlorinated hydrocarbons do not usually kill the bird out right. Rather, DDT and its relatives al