Blue-footed boobies are less likely to commit siblicide and if they do, they commit it later after hatching than masked boobies. In a study, the chicks of blue-footed and masked boobies were switched to see if the rates of siblicide would be affected by the foster parents. It turns out that the masked boobies that were placed under the care of blue-footed booby parents committed siblicide less often than they would normally. Similarly, the blue-footed booby chicks placed with the masked booby parents committed siblicide more often than they normally did, indicating that parental intervention also affects the offspring's behavior.