Hey! Blue Jay!
Canada.com has an article about iScarecrow the screaming robot that battles birds. Noble Vision robotics created iScarecrow to scare off birds who feast on grapes in Canadian vineyards. Birds cost vineyards billions every year in lost harvests and revenue. The central control system detects the birds with a camera and then sends out the appropriate robot run along a wire track and screech at the birds to scare them off. The iScarecrow system detects and reacts to birds only when they are present so the birds don't get wise.
Meerkat (o'reillynet) 07/18, link to iScarecrow article at robots.net