Bird word Torpidity: A slow down or reduction in bodily functions in reaction to cold or stress or to save energy. Our chickadees exhibit a degree of torpidity on cold winter nights to conserve energy.

Water in winter Birds need water year-round. Offering birds water during the winter can significantly increase bird traffic in your yard. Bird-bath heaters, electric devices to keep the water from freezing, are available at pet and hardware stores.

Oh, and it's just as important to keep water fresh and clean in winter as it is in summer. Refill your birdbath often.

Bird book in brief National Geographic, big in the bird-book business in recent years, has published a fine companion to its bird-identification books. "Birding Essentials" is indeed an essential primer for birders. Other authors and publishers have tried this, but no one has done it as well.

Authors Jonathan Alderfer and Jon Dunn, both highly respected in national birding circles, here offer "all the tools, techniques and tips you need to begin and become a better birder."

In clear, crisp text they discuss the what, why and how-to of binoculars, identification techniques, bird distribution and more.

The best chapter might be the last: "Fieldcraft." It includes tips on "how to search for birds, how to move and how to communicate what you see to others." It also includes the authors' suggestions on valuable birding periodicals and books, which is particularly valuable.

At a mere $15.95, this book is a must-buy for birders.

JIM WILLIAMS