Stocking birdfeeders during the winter months can help the birds when their food supply is scarcer.

During these briefest days of winter, with the trees draped in snow, the brave little birds puff out their feathers to bear the cold.

Stocking birdfeeders can help the birds during these months when their food supply is scarcer. Watching the frenzy of the birds and the antics of the squirrels that visit the feeder can be amusing and educational, but feeding the birds is intervening in the lives of wild animals, and care needs to be taken so as not to inadvertently harm them.

Linda Cocca, coordinator of the Mass Audubon Wildlife Information Line, recommends using black oil sunflower seed, since almost every bird that will visit a feeder eats it. She says seed mixes often include a lot of waste. The cheap mixes can also include invasive, non-native seeds that can sprout under the feeders or be spread into wild areas through bird droppings, potentially harming native wild habitats.

She cautions that baked goods are not good for the birds, because they fill the birds up with empty calories. Suet provides healthy calories and will attract a variety of woodpeckers and nuthatches.

The seed should be fresh. Old or moldy seed can host Aspergillus fungi, which causes a serious respiratory disease in birds. High concentrations of birds around a birdfeeder can cause an accumulation of bird droppings where salmonella bacteria can grow and contaminate seed, which can be fatal to the birds.

One prevention method can be to have perch-feeders where the bird droppings fall to the ground. It is also helpful to not locate birdfeeders next to each other.

Cocca says it is important to clean feeders every two weeks, especially in the warmer weather. They can be soaked and scrubbed with a solution of 10 parts hot water and one part bleach, then rinsed with water. The birdfeeder should be completely dry before filling with seed. This method works best with plastic or metal feeders, not wood, which tends to retain moisture.

Cocca adds that the best food is the native plants where the birds can naturally feed.

Matt Pelikan, director of the Islands Program at The Nature Conservancy, says that the site of the feeders is important. Pelikan urges people to set up their feeders so there is a tree or bush close by for cover, but not "cat-pounce" close.

He recommends not having the feeders right outside of house windows, since flying into windows is a major source of mortality for birds. He leaves his screens up to soften the impact in case birds do fly into a window. Heated birdbaths will attract a greater variety of birds.

He also says that brush piles about 5 feet high will provide shelter and protection from predators. Pelikan believes the citizen bird counts are helpful with tracking bird populations and distribution over time and are definitely worth participating in.

Get your kids off the computer screen and engaged with nature by participating in Audubon's Focus on Feeders count Feb. 6 and 7. It is easy, fun and an educational activity for all.

Anne Mazar is an environmental advocate and a member of the Mendon Land Use Committee.