How exactly does DDT harm the peregrine falcon?

DDT, or dichlorodiphenyltrichloroethane, is a synthetic organochlorine compound formerly used as a pesticide. It was widely used in agriculture and public health from the 1940s to the 1970s, before its use was banned in most countries due to its harmful effects on the environment and human health.

In the case of the peregrine falcon, DDT primarily affects its reproductive system. When peregrine falcons consume prey that has been contaminated with DDT, the chemical accumulates in their body fat. As DDT is a persistent organic pollutant (POP), it does not break down easily and can stay in the environment, including the food chain, for many years.

When female peregrine falcons lay eggs, the DDT stored in their body fat is transferred to the eggshells, making the shells thinner and more prone to breakage. This can result in eggshell thinning, reduced hatching success, and ultimately a decline in the peregrine falcon population. In addition to eggshell thinning, DDT can also cause other reproductive problems in peregrine falcons, such as reduced fertility, embryo mortality, and developmental abnormalities in young falcons.

The impact of DDT on the peregrine falcon was first documented by the American biologist Rachel Carson in her book "Silent Spring", published in 1962. Carson's book raised public awareness about the dangers of DDT and other pesticides, and played a significant role in the movement to ban DDT and other harmful chemicals.

Thanks to the ban on DDT and conservation efforts, the peregrine falcon population has since recovered and is no longer considered endangered. However, DDT and other persistent organic pollutants still pose a threat to wildlife and the environment, and their use and regulation are subject to ongoing scientific research and policy discussions.