A recent alarming story in the U.K.’s Daily Mail reminds us that backyard birdfeeders can provide perils as well as perks for birds. According to the British Trust for Ornithology, diseases spread by birdfeeders that aren’t cleaned regularly have killed up to one-fifth of Britain’s greenfinches. In the U.S., an estimated 60 percent of house finches have been wiped out by an infectious eye disease called “mycoplasmal conjunctivitis.”
In order to prevent diseases like salmonella, trichomaniasis, and avian pox that can be spread by dirty birdfeeders and birdbaths, the Audubon Society recommends cleaning feeders and baths at least once or twice a month with a solution of nine parts water to one part bleach. They also recommend emptying birdbaths and refilling them with fresh water daily, scattering birdfeeders around the yard instead of clustering them in one place, and raking or sweeping up uneaten hulls, which can harbor diseases for several days.
The threat of spreading diseases is one reason why PETA recommends that birdwatchers rely more on planting flowers, trees, and shrubs that attract birds as opposed to stocking birdfeeders during the growing season. (Birdfeeders are best used during the winter, when birds are less able to forage on their own.) Filling your yard with plants like holly, cotoneaster, pyracantha, viburnum, and snowberry can provide cover and nesting opportunities for birds, in addition to food.