According to surveys and research by many different scientists, pesticides can severely affect the population of various species of birds. For example, pesticides like neonics and organophosphates, are direct factors that can alter the bird population. DDT had a significant effect on eagles and fish in the 20th century. But, as a result, Rachel Carson brought the epidemic to the public’s attention by publishing her book, Silent Spring. After these factors were discovered/publicized, the production of the harmful pesticides reduced massively, eventually diminishing to nothing; this led to the flourishing of bird and other animal populations.