In Spain, a striking and innovative initiative is bringing together wildlife intelligence and public-venue maintenance — crows are being trained to collect litter during and after large open‑air events, such as concerts and sports matches. These exceptionally smart birds, celebrated for their remarkable problem‑solving abilities and capacity for social learning, are taught to pick up cigarette butts, bottle caps, wrappers, and other small trash. When they deposit a piece of litter into a specially designed feeder, they immediately receive a food pellet — typically grain or corn — as a reward.

This pilot project is in operation at several outdoor stadiums across Spain, where waste left behind by crowds is a chronic problem. The program relies on custom “smart bins” strategically placed around venues. These feeders are equipped with a slot: when a crow drops litter in, a sensor or simple mechanical trigger immediately dispenses a treat. The birds adapt remarkably quickly to this exchange system, often mastering it after only a few trials. Even more impressively, the crows have been observed sharing the behavior with one another — younger or untrained birds learn simply by copying more experienced members of the flock, highlighting the social learning capacities of corvids.

What makes this method particularly remarkable is how well it aligns with natural behaviors. Rather than increasing mechanical infrastructure or hiring more cleaning staff, organizers are leveraging nature itself. Crows are especially well-suited for this kind of task: they are highly adaptable, possess excellent spatial memory, and can recognize human-made tools and patterns. These traits make them ideal “partners” in a cleanup effort.

Crucially, the program is designed with ethical safeguards. The birds are not coerced in any way — participation is voluntary, and the feeders are only stocked for limited durations to avoid overfeeding or creating dependency. Avian behavior specialists closely monitor the project to ensure the birds’ welfare, tracking how often they use the feeders and ensuring they continue to forage naturally as well.

Beyond being a clever gimmick, the initiative offers a genuinely low-carbon, low-noise solution to post-event litter. It reduces reliance on vehicles, machinery, or large cleaning crews. At the same time, it inspires a sense of wonder: visitors often stop to watch these feathered “cleaners” in action, which can also raise environmental awareness and engagement.

Though this exact approach is new in Spain, similar experiments have been tried elsewhere — notably in France. At the Puy du Fou historical theme park in western France, six rooks (a species of crow) were trained to pick up cigarette butts and small rubbish items, depositing them into a box in exchange for food rewards.  According to HowStuffWorks, corvids are used because of their advanced cognition — tool use, planning, and social memory are all part of their natural repertoire.  The falconer behind the French project, Christophe Gaborit, even observed that some rooks attempted to “cheat” by picking up sticks or wood chips — but the system was designed so only genuine litter would trigger a reward. 

Beyond cleaning, the French project carried a broader educational message. Park officials said their goal was not just to reduce litter, but to show visitors that “nature itself can teach us to care for our environment.”  By giving people a concrete example of intelligent wildlife contributing to a shared space, the initiative invites reflection on how humans and animals might live more cooperatively.

In sum, the program in Spain represents a novel convergence of ecology, behavioral science, and urban management. By tapping into corvid intelligence and shaping it in a humane, reward-based way, organizers hope to build a sustainable, scalable model for litter control — one that respects nature while harnessing its power for public good.