Laura Erickson's For the Birds

Birds are physiologically able to conserve water more efficiently than mammals can, but they still require drinking water to survive. Because they can fly to ponds, lakes, and other natural water sources, in most areas they get by quite well without birdbaths. In winter, their bodies are extremely good at conserving water, and they can eat snow or drops from melting icicles. But providing water in backyard habitats can support a larger number of birds, and easily available, safe drinking water makes their lives easier. Birds are attracted to the sound of water running or dripping, so recirculating fountains and slow drips attract many more birds than simple birdbaths do.

Plastic and ceramic birdbaths may have slippery slopes. If yours does, add sand or rough stones to the bottom to provide birds with better footing. In summer, the best location for a birdbath is in the shade, to minimize evaporation and algal growth. The activity at birdbaths often attracts neighborhood cats and other predators, and birds with wet feathers are often clumsy fliers, so it’s best to situation birdbaths near trees or shrubs where the birds can retreat if a predator is spotted.

Cleanliness is important

Some birds, most notably grackles, dispose of their nestlings’ fecal sacs over water. In natural settings, they choose lakes or streams, but in urban and suburban settings, they may use swimming pools, shiny automobiles (on sunny days, the shimmering surface has a watery appearance to a grackle’s eyes), or birdbaths. And when birds bathe, dirt, germs, parasites, and droppings remain behind. Also, the mosquito species most likely to carry encephalitis and West Nile virus often lay their eggs in birdbaths. Be sure to change the water every two or three days to keep it clean and to destroy mosquito eggs before they hatch. A quick weekly scouring with a wire-bristle brush and a hose is usually adequate maintenance.

Birds are also attracted to lawn sprinklers. set to provide a fine spray. It’s best to run these in the early morning or evening, when cooler temperatures minimize evaporation. If water shortages are an issue, recirculating ponds and sprinklers may be inappropriate. In this case, you can suspend a water-filled container with a slow leak—a tin can with a small puncture in the bottom or a water bottle with the drinking spout barely open—from an overhanging branch. Set a small birdbath underneath to catch the dripping water. Once or twice a day, refill the drip source from the tap or even from the birdbath itself.

Constructing a backyard pond will provide water for your regular birds and attract passing migrants as well. If you want to stock your backyard pond with aquatic plants, fish, frogs, or other creatures, make sure to use only species that are native to your area. (Beautiful as they are, exotic fish such as Koi are not a good idea; they will attract predators and may expose native wildlife to exotic diseases.) These ponds are best constructed so that they are filled by natural rainfall rather than municipal water supplies, which is especially important if water shortages are an issue.

Should you provide water in winter? Even though birds seem to especially enjoy birdbaths when their natural sources are frozen solid, heated birdbaths use electricity; wasting energy is ultimately a much more serious problem for bird populations than winter water shortages are. Fresh water set out in the morning may remain unfrozen for several hours, but during extreme cold, water vapor can be dangerous if it condenses on feathers. During freezing weather, birds simply should not bathe. I’ve read of several instances of birds, usually starlings or Mourning Doves, bathing in heated birdbaths in winter and then, after flying off, suddenly dropping like stones when their wet wings or tail feathers froze. If you do provide water in winter, cover the birdbath with a nonmetallic mesh grille (perhaps constructed of wooden dowels) that allows birds to insert their beaks for drinking but prevents them from immersing their bodies.

From 101 Ways to Help Birds, published by Stackpole in 2006. Please consider buying the book to show that there is a market for bird conservation books. (Photos, links, and updated information at the end of some entries are not from the book.)