I feel that a birdbath is among the best additions you can make to the backyard, for any lot of reasons. But before I go into those, hear me says: Eliminate your bird feeder!
That is right. Eliminate your bird feeder and instead attempt to create your entire garden a pure bird feeder, with the food-rich habitat that birds will seek out on their own: simply add water. Sure, bird feeders bring a great deal of interesting birds, but at what cost? Birdfeeders also attract squirrels, raccoons, and, in my city, bears.
Are bird baths a good idea?
OK, here is what a bird bath can do for your garden. Birds will come to your birdbath for the water that they want — for drinking and for dressing. While they are hanging around they will search for the insects and worms and seeds and flower parts they like to consume. In the process, they’ll help aerate the soil, help groom dead plant material, and help keep plants healthy as they devour insects. Yes, birds can eat some fruit, especially in the event that you grow berries or cherries, but gardeners can certainly take steps to mitigate losses.
The birds feeding in your backyard will show you more about their normal behavior than they will at a feeder.
Here is an unexpected bonus: bird baths give wasps and other beneficial insects a place to cool off and drink in the hot summer months, and a few of them, such as the wasps, are enormous predators of cabbage worms and other harmful pests.