Garden bird feeding is one of the most widespread wildlife interventions by the public. Done well, it benefits bird populations and individual bird welfare. Done poorly, it can spread disease.
Bird feeding can make the difference between survival and starvation during harsh winters, particularly for species like coal tits and nuthatches. However, dirty feeders become disease vectors, and poor feeder placement increases predation risk. Best practice guidance from organisations like the RSPB helps maximise welfare benefits while minimising harms.