Crows have been “recruited” to pick up discarded cigarette butts from the streets of Stockholm as part of the Swedish capital’s cost-cutting efforts. The wild birds carry out the task voluntarily, because they receive food for every butt that they pick up. Corvid Cleaning, the company behind the project, estimated that using the birds could save at least 75 per cent of the costs involved with picking up cigarette butts around the city. New Caledonian crows found in Sweden appear to be well…