Drinking water entices birds year-round, but keeping it ice free in winter can be a challenge. Birds have several physiological mechanisms for conserving water, but in our area we do not get the snow that birds can use. Providing a source of water when everything around is frozen offers a huge benefit for the birds.
On those below freezing cold days like we recently experienced, birds will use baths for drinking and bathing. The simplest way to provide water in winter if you do not have a birdbath is to set out a plastic bowl at the same time each day, and bring it in when ice forms.
If you have a birdbath and want to keep it ice-free during sub-freezing days, you have several choices. Manufacturers now offer birdbaths with built-in, thermostatically controlled heaters. Immersion heaters are also available. Most new models turn off if the water in the bath dries up. Ideally, plug your heater into a ground-fault interrupted circuit (available from hardware or electrical supply stores) to eliminate the chance of electric shock.
Content of this article provided by The Cornell Lab of Ornithology