Recent Effects of DDT in Raptor Populations
Although the pesticide has stopped being used in many parts of the world before the 2000s, it is still causing species declines today.
What is DDT?
Dichloro-diphenyl-trichloreothane, or DDT, is a chemical that started being used in the 1940's as a pesticide. It was created to combat deadly vector borne diseases such as Malaria. A short time after use started, it was realized that DDT had serious effects on public health and the environment. Towards the turn of the 20th century, the Stockholm Convention on POP's treaty was created against DDT giving it limited emergency use, but can still be found even in places that banned its use over 20 years ago due to how long it takes to breakdown in the environment.
One concern that has weighed heavy on the environmental community is the population size of raptors. They suffered a severe decline in the mid 1900's due to DDT and other pesticides. Even in recent studies, DDT has been found in raptors. Despite this, there is hope for recovering from the effects of the pesticide.
The Cooper's Hawk serves as an example of recovery from DDT in the United States.
After the 1970's when the use of DDT was prohibited, there was an increase in the amount of many different species of raptors, but The Cooper's Hawks numbers have been increasing throughout the years, being able to adapt to urban ecology.
Why are raptors important?
Raptors maintain a high place in the food chain no matter what ecosystem you look at. They provide key information to researchers about the health of any ecosystem they are present in. Studies on apex predators are preferred over aquatic studies due to the larger range of information they are able to gain from it.
The Need For DDT
In less developed nations, DDT is still used because it is cheap and very effective at fighting malaria. In these countries listed in red on the map, it has been decided that the risks of using DDT do not outweigh the benefits of fighting insect related illnesses. The size of the dots is dedicated to the amount of declining species in each country ranging from 1 to 63. There is evidence to suggest that some of the countries not listed also have DDT present or currently use it.
Declining Species and The Presence of DDT
In these places that reported still actively using DDT such as Cambodia and Kenya, there is a clear decline of raptor species and a rise of threatened species.
Controversy Persists Over DDT
Other chemicals are used in countries to cut down the amount of DDT used or to replace it entirely as a pesticide, but other alternatives are usually costly or do not keep the mosquitoes away for as long. Perhaps the most viable alternative to spraying DDT and other harmful insecticides is the prevention of malaria through routes such as vaccines and pharmaceutical treatments. Until better alternatives are readily available, vector-borne illness is a top priority of health leaders.
It has been proven by The Cooper's Hawk and other raptor species of North America that a population resurgence after a DDT event is probable. Unfortunately, as long as DDT remains prevalent in the environment, the raptor's food source remains poisoned and populations cannot recover themselves without healthy nutrition.
