text: In some of the instances where DDT was alleged to have killed birds, other factors from excess hunting to mercury poisoning were more likely the real culprits. Further, the bird population would often increase in areas spread with DDT as there were fewer insects to spread bird diseases. Ironically, today the mosquito-borne West Nile virus is killing many of the birds including robins, condors, eagles and peregrine falcons alleged to have been harmed by DDT. Yet greens still oppose most spraying programs that use any type of pesticide to fend off mosquitoes.