If safety guidelines are followed, feeding wild birds can be great for them and the environment. Especially after a harsh winter, many birds rely on feeders when they return home, and their natural food sources are still affected by the cold. You can take measures to ensure your feeders are harmless to the birds using them, including cleaning them with disinfectant solutions a few times a year and choosing feeders that cater to native birds in your area.
Even the best wild bird seed mix can cause an overabundance of birds at one feeder. You should also place different types of feeders and food at different locations in your yard, so birds of different species can have their own spaces—this also helps prevent diseases from spreading.