The peregrine falcon became an endangered species primarily due to the use of organochlorine pesticides, especially DDT, whose breakdown lowered estrogen levels in the female peregrine bloodstream and inhibited the production of calcium, causing eggs to grow thinner by up to 20 percent.
The peregrine falcon became an endangered species primarily due to the use of organochlorine pesticides. This was especially DDT. This DDT was causing eggs. This was to grow thinner by up to 20 percent. DDT's breakdown lowered estrogen levels in the female peregrine bloodstream. DDT's breakdown inhibited the production of calcium.