We really like this four season bird bath. It has a rough surface, which birds can easily cling to. The very small birds, like chickadees and finches, won't use birdbaths with slippery surfaces for fear of drowning. If they can't confidently get their footing, they're less likely to use the birdbath. Molded from very tough ABS polymer as used in football helmets.
Surface is sand coated to provide a weather-resistant textured surface.
Lightweight and easy to move. Heater warrantied for two years. Dripper will not work in below freezing conditions. Shelter Birds need shelter to protect them from the weather and from predators, and to provide a place in which to roost at night. Shelter can also provide nesting spots for birds to raise their young.