Other than a good meal, few things are more attractive to birds than a safe place to bathe, drink, and socialize with other birds. Offering birds fresh, clean water in a birdbath is great way to attract them to your yard and garden. The birdbath you choose doesn't need to be fancy, but there are a few things to consider if you want to make it a popular year 'round attraction for your backyard feathered friends.
When choosing a birdbath, keep the comfort of the birds in mind. For example, a narrow rim makes for a more comfortable perch - especially for song birds with tiny talons. The bottom of the water basin should have a bumpy surface rather than one that is smooth and slippery. This can be accomplished by adding some rough rocks or sand for texture, or by placing a few non-skid stickers at the bottom to give the birds some extra grip.
Depth: In nature, birdbaths come in the form of shallow puddles. In your backyard, an ideal birdbath will be no more than 1 to 2 inches deep, and have a sloped basin that allows birds to ease their way and out of the water.
Height: The height of the birdbath affects which types of birds will use it. Small birds usually prefer taller birdbaths that give them a wide field of view. Larger birds, like doves and crows, prefer to drink (and eat) at ground level. A birdbath that is raised two or three feet off the ground will attract the widest variety of birds while offering them reasonable safety from nearby predators.
Water in motion: Birds are instantly attracted to water that gurgles, splashes, and drips. Adding an element of moving water to your birdbath will attract more birds as well as helping reduce insects and algae growth. Drippers, water sprays, and bubblers are available commercially, or you may want to consider choosing a fountain design that runs on electricity or solar power.
Place your birdbath in an open area of your yard. It should be near some trees, but away from shrubs and other structures that predators (like cats) like to hide. A shady spot will slow down water evaporation and help keep the water fresh. Branches from nearby trees will give birds an escape route, as well as a convenient place to sit and preen after bathing.
The key to attracting a large number of birds is to keep your birdbath clean and full of water at all times. Leaves, insects, and other debris will find their way in, so give your birdbath a quick scrub and rinse every couple of days, when it's time to refill it with fresh water. Don't let the water become stale, and clean off the bottom of the basin immediately if you see green algae starting to form.
In the winter, drinking is the main activity at birdbaths. When birds have access to open water, they can use their energy for heat and survival rather than for converting snow into something to drink. Immersion style heaters (available wherever birding supplies are sold) are designed to keep water temperatures just above freezing. The latest models will automatically turn off if the water in the birdbath dries up and cost only pennies a day to operate.
If you opt for a heated birdbath, make sure you put the heater on a ground-fault interrupted circuit to eliminate the danger of electrical shock. An alternative is to put out a small basin of water at the same time each day. Neighborhood birds will quickly learn your schedule and be eagerly waiting for you to arrive.