 In the United States , common starlings are exempt from the <unk> Bird Treaty Act , which prohibits the taking or killing of migratory birds . No permit is required to remove nests and eggs or kill juveniles or adults . Research was undertaken in 1966 to identify a suitable <unk> that would both kill common starlings and would readily be eaten by them . It also needed to be of low toxicity to mammals and not likely to cause the death of pets that ate dead birds . The chemical that best fitted these criteria was DRC @-@ <unk> , now marketed as <unk> . In 2008 , the United States government poisoned , shot or trapped 1 @.@ 7 million birds , the largest number of any nuisance species to be destroyed . In 2005 , the population in the United States was estimated at 140 million birds , around 45 % of the global total of 310 million . 
