Backyard Bird Bath: Depth, Placement and Cleaning

Yes, if you keep it clean: a backyard bird bath gives birds water for drinking and bathing and brings species that never visit a seed feeder. The catch is hygiene. Audubon lists house finch eye disease, salmonellosis, avian pox and avian flu among the illnesses that can spread at a dirty bath, and stagnant water lets mosquitoes breed. A bath you can refill every day or two helps birds; one left for a week does not.

Shallow, gently sloped and not slippery. The guidance from four sources lines up:

• Depth: Sacramento Audubon says 1-2 in; Penn State Extension says no more than 2-3 in at the deepest point. Shallow water gives young birds confidence.
• Slope and width: the RSPB recommends very shallow sloping sides, a maximum depth of about 10 cm and a width of more than 30 cm if you can.
• Grip: Penn State says birds dislike slippery surfaces and suggests concrete or terra-cotta over glazed pottery, or small rocks and bathtub stickers for traction. Sacramento Audubon suggests large pebbles or flat rocks set slightly above the waterline.
• Material trade-off: Sacramento Audubon prefers hard plastic because it is easier to clean and durable, while Penn State prefers concrete or terra-cotta for grip. If you choose plastic, add stones for footing.

Height matters too. Penn State says pedestal baths attract the common feeder birds, such as chickadees, finches and titmice, while a ground-level bath brings less common species and other animals like squirrels. Sacramento Audubon suggests keeping the bath as close to the ground as possible, since birds naturally drink from puddles. Offering both covers both groups.

Shade or part shade. Sacramento Audubon says a shady or partly shady site keeps the water cool so birds can cool off, and Penn State adds that shade reduces algae and overheating.

The rest of the placement is about predators and dirt:

• Cover close, but not too close: bushes or trees nearby give birds an escape route (Sacramento Audubon). For a ground bath, Penn State says to keep it 10-15 ft from shrubs where a cat could hide, so birds see it coming. The RSPB puts it in an open flat area with no long grass or low bush for a cat to pounce from.
• Not under the feeder: Audubon and Penn State both advise against placing the bath directly under feeders or brush, which drop seed husks and droppings into the water.
• Away from runoff: Penn State warns against spots that collect lawn or road runoff with herbicides or fertilizer.
• Where you can see it: the RSPB suggests a spot you can watch, which is also where you can photograph visitors for identification.

Change the water every one to two days. Sacramento Audubon says every 1-2 days, Audubon says every other day, and Penn State says daily where West Nile virus is present, so mosquito larvae never hatch.

For scrubbing, Audubon and Sacramento Audubon both use nine parts water to one part vinegar and say to skip synthetic soaps and household cleaners; Audubon explains that they can strip the natural oils from feathers. Penn State suggests a weekly scrub to remove algae. Rinse well before refilling.

People add copper pennies hoping the copper will stop algae. Birds & Blooms says it does not work well enough to rely on and may harm birds. It quotes Kenn and Kimberly Kaufman: algae eventually grows in every birdbath, even copper ones, and the other metals in pennies might contaminate the water. US pennies were 95% copper and 5% zinc before 1982 and have been 97.5% zinc with copper plating since, and Ken Keffer tells the magazine the zinc in newer pennies is a concern. The advice from all of them is the same: there is no substitute for frequent cleaning.

• Drippers and misters: Penn State says the sound and sight of dripping water attract birds, especially hummingbirds, and that a punctured water bottle hung above the bath makes a simple dripper.
• Mosquitoes: Audubon suggests a fountain or stream feature, since mosquitoes do not lay eggs in running water.
• Winter: Penn State and Sacramento Audubon both mention heated baths or submersible heaters to keep water above freezing; Penn State notes solar heaters fail on cloudy days.

• Basin 1-2 in deep with a gentle slope, a rough surface or a few flat stones.
• Shade or part shade, shrubs within a short flight but 10-15 ft from cat cover for a ground bath.
• Not under the feeder, not in a runoff path.
• Fresh water every 1-2 days; scrub with 9:1 water and vinegar.
• No pennies; a dripper in summer, a heater in winter.

A bath is one of the best places to photograph birds, because they stay still to drink and preen. BirdLens suggests the species from a photo. Compare the result with backyard birds, and if a hawk turns up at the bath, as the Sharp-shinned Hawk in Birds & Blooms' reader photos did, see hawk identification. For food alongside the water, see best bird seed for wild birds.

Research and drafting for this page were assisted by AI and checked line by line against the sources listed below. If you find an error, tell us and we will correct it.