The crows turn in their collected cigarette butts for food:
Over in the Swedish city of Södertälje, about 30 km southwest of Stockholm, a pilot program is being explored which will enlist crows to clean up discarded cigarette butts. Butts account for over 60% of litter in Sweden, and the per-butt cleanup cost falls between 0.8 and 2 Swedish kronor each. The company behind the project, Corvid Cleaning, estimates the cost will be around 0.2 kronor. If the birds picked up all the butts, that would be a substantial savings, but in reality, the current manual cleaning will still be needed. Total savings to the city will depend on the ratio of bird-collected vs. people-collected butts.
Here is the link, via Chris Harges.