In sub-zero temperatures, there’s no such thing as liquid water. Birds always need water, but if none is available, they have to get it from food that contains water, such as the bodies of insects, or wild fruits and berries. Or from eating snow.
Or… from a heated birdbath.
A birdbath with open water is a gift that birds gladly accept. It can bring birds to your backyard that don’t eat birdseed and would not visit most bird feeders.
The special cost of eating snow
Snow is made of ice crystals. Ice is solid because its water molecules are held together in a crystalline structure. What keeps ice rigid is the hydrogen bonds between its molecules.
It takes energy, such as heat, to break those bonds. As heat breaks the hydrogen bonds, the ice melts. When ice first melts, the meltwater is just as cold as the ice it came from. After that, additional heat starts warming up the water.
When a bird eats snow, all the heat has to come from the bird’s body. Most of that heat (2/3) goes just to change the snow to water. The rest (1/3) brings the water up to body temperature.
Unfrozen water in the bath saves the birds a lot of calories.
How birds keep warm
Energy comes from food. Birds eat more food in winter than in summer because they need the extra calories to keep warm. Many birds spend almost every waking winter moment finding food. It’s a matter of survival.
If birds can save the cost of eating snow, they can conserve calories. Your little circle of liquid water may be the crucial factor that helps a bird to survive the coldest night of the year.
Here are a few things to keep in mind when you add a birdbath to your backyard.
Heating up
You want to offer liquid water. You can add a birdbath warmer to an ordinary birdbath. Better yet is a bath with a built-in heater, as it eliminates the problem of a separate warmer getting knocked out of the bath.
Put it up high
Locate the birdbath where you can run an outdoor-rated electric cord to it.
An elevated bath is better than a bath on the ground. Think pedestal or a deck railing. Nearby trees can allow a bird to flutter up into safety if danger threatens.
Keep it clean
Put it at a distance from your bird feeding station, so that seeds and droppings don’t quickly soil the water.
I take a gallon jug of warm water out every morning, give the bath a quick scrub with a brush I keep nearby, and replace the water. If you locate the bath in reach of a hose, it will be easy to keep clean in summer, too.
In view from a window
Don't forget to put yourself in the picture. Place the birdbath where you can see it from indoors, from your desk, dining room, or kitchen sink.
A bird drinking from a birdbath is a flood of happiness.
Is this your birdbath? How impressive!
An aging, frugal farm boy here. I use a heated dog dish with a rock in its middle to water the birds. It works well. Nary a complaint from a single bird. A young great horned owl dipped its talons in the dish this fall. Everything is copacetic.