The first conception of the modern filtered cigarette emerged on the market in the 1950s, and the environment has been bearing the brunt ever since. Cigarette butts remain one of the most common forms of plastic pollution globally. On the streets of Sweden they make up 62% of all litter according to the Keep Sweden Tidy Foundation. In an effort to clean the streets and cut the costs, a startup in Södertälje near Stockholm are enlisting the help of wild birds to do the dirty work.

The project, which is still in development, aims to train crows, magpies and other corvids to deposit litter in a specially designed vending machine that spits out food in exchange for garbage.

“We get help cleaning up the trash, they get some yummy food,” reads the description on the website for Corvid Cleaning, the company behind the initiative. The bin is designed to distinguish between litter and other items like stones or leaves and will only dish out rewards when the birds deposit actual trash (mainly cigarette butts).

Corvids – a family of birds that includes crows, magpies and jackdaws – are widely celebrated for their intelligence. Some studies suggest crows have reasoning skills that are on par with a 7- to 10-year-old human. According to Christian Günther-Hanssen, founder of Corvid Cleaning, the birds "have no issue understanding the trade of litter for food.” In addition to this, they are hardy urban adapters and already live in human-shaped environments.

“They are easier to teach and there is also a higher chance of them learning from each other.” Günther-Hanssen told The Guardian. “At the same time, there’s a lower risk of them mistakenly eating any rubbish.”

Crows are widely considered to be among the most intelligent birds on the planet.

Sweden spends a considerable amount of money each year on keeping their streets clean – something the new initiative aims to assist with. “The estimation for the cost of picking up cigarette butts today is around 80 öre [9 US cents] or more per cigarette butt, some say two kronor [22 US cents],” Günther-Hanssen explains. “If the crows pick up cigarette butts, this would maybe be 20 öre [2 US cents] per cigarette butt. The saving for the municipality depends on how many cigarette butts the crows pick up.”

If this all sounds familiar that’s because the idea for avian-powered cleaning contraptions has been on the cards since at least 2008 when Joshua Klein presented his idea for a bird vending machine at a TED Talk in the USA. More recently, a father and son team in Partille, Sweden enjoyed some success at getting wild magpies to pick up an assortment of trash from their garden and deliver it to a specially designed feeder.

While there’s something endearing about the idea of urban birds being employed as winged refuse removers, corvid cleaning operations still have a stack of ethical and logistical issues to resolve before the projects can be implemented in the real world.

First and foremost are concerns over the wellbeing of the birds that are being enlisted to root around in human trash. “What we do know so far is that cigarette butts contain a lot of nicotine and other compounds that are dangerous if inhaled or ingested,” Günther-Hanssen explains on the Corvid Cleaning website. “Since the birds will do neither it’s unknown if they will get anything in them at all.” Urban birds are certainly better equipped to deal with our leftovers than other wild species and many of them already forage in rubbish dumps and on litter-strewn streets. It’s possible that the opportunity to exchange non-food items for something more nutritious may have a positive effect on the birds’ health, Günther-Hanssen theorises, but admits that further testing is required.

Then there’s the question of just how much of an impact these projects will have on bird behaviour. At the very least, scoring treats for trash will alter the birds’ foraging routines, which admittedly in the case of urban birds already take place in human-shaped environments. Günther-Hanssen is optimistic that the impacts of the project will be more of a behavioral shift than an overhaul: “Their current behaviour is not 'natural' as such, so it’s not necessarily a big change for them to just interact with the human world in a slightly different way.”

Christian Günther-Hanssen, founder of Corvid Cleaning, shows off his avian vending machine at Science Week organized by Södertälje Science Park. Image © Fredrik Sederholm

Of course, these ethical questions are moot if the project fails to actually deliver what it aims to achieve. Wild birds are exactly that and their foraging behaviour may depend on a slew of as yet undetermined factors. It seems logical that corvids with their recognised intelligence would swoop at the chance to nab an easy meal, but that remains to be seen. Test show that they can be trained, but whether or not they'll hit the streets as full-time cleaners is unknown.

Perhaps the most compelling question raised by the initiative is how we arrived at this problem in the first place. “[W]e can teach crows to pick up cigarette butts but we can’t teach people not to throw them on the ground,” Tomas Thernström, a waste strategist at Södertälje municipality told The Guardian. “That’s an interesting thought.”