Winters, whether mild or harsh, are challenging times for birds. Food is in shorter supply just when birds need lots of energy to help them survive the cold.

That's where suet feeders come in. Birds eat suet — cow fat — for its caloric content. Chickadees and cows use suet in exactly the same way. The hard white fat you feed to birds is energy.

Cows save their suet for energy emergencies. Those were more likely to happen when cattle were wild beasts as opposed to feedlot residents (where they face only one emergency, and suet is of no help).

Cow suet surrounds the animal's kidneys. A butchered cow provides 20 to 30 pounds of suet. That large quantity is the result of a fattening diet that goes beyond the needs of well-marbled steak.

My suet feeder, homemade and large, attracts chickadees, nuthatches, blue jays, the occasional brown creeper and four species of woodpeckers — downy, hairy, red-bellied and pileated. We get crows, too (pigs with wings).

Why don't we put out suet year-round? Suet melts at 112 degrees. There are summer days when it dribbles if touched by the sun. That's messy. Suet is best used in winter.

Finding a supplier

Once upon a time the butcher, asked politely, would reach over the counter to hand you a small package, a chunk of suet wrapped in white butcher paper. The butcher would scribble NC on it — no charge.

Not so today. Checking the Internet for suet pricing information I came upon a quote from a man named Dan. "That guy paying $4.95 a pound — bud, they seen him coming," Dan wrote.

Phone calls in early December, mostly to butchers at small packing houses on the metro periphery, found prices ranging from $1 a pound to $4.89 (bud, they seen you coming). Lunds has suet for $2.79 a pound. At Cub the same day — $2.99.

Feeder design

Our feeders for years have been built of half-inch hardware cloth fastened to a piece of 2-by-6 pine. The current feeder cage bulges at 8 by 14 inches, 2 inches front to back. The top edge of the wire can be pushed inward to thwart crows. This feeder looks rough but costs little.

I cut my large suet chunks, wholesale and fresh from the cow, into 2-inch slabs. They slide right in, tight against the wire. Even short-billed birds have easy access.

Our neighborhood bird store has wire suet cages that measure 5 by 5 by 1.5 inches for $4.99 (and larger ones for more). Cub's cage was $3.69. You can fill these with suet cakes costing $1.99 at Cub, $2.79 at the bird store. There are various ingredient mixes, some costing more.

Another feeder design uses suet or a suet mixture to plug 1-inch holes drilled in small log sections that you hang. There are manufactured suet plugs for you to buy, as you might guess.

Suet cakes and plugs, designed for the feeders, strike me as the old safety-razor gambit — sell the razor cheap, make money on the blades.

Make your own

Retail suet cakes basically contain suet with grain binders — corn meal, oats, millet, sunflower meal. Some are jazzed up with peanuts, freeze-dried meal worms, seeds and fruit.

Or, make your own. The Old Farmer's Almanac recipe is basic: two parts melted fat (bacon, suet or lard), two parts yellow cornmeal, one part peanut butter. Mix ingredients, cook for a few minutes, pour into small flat containers (tuna fish cans work, about half full to fit in a cage), and refrigerate or freeze until needed. That sounds less expensive.

Or google "suet cakes." Recipes are endless.

If you buy cakes at the store, remember that the added ingredients, always boosting the price, probably mean more to you than to the birds.

Lifelong birder Jim Williams can be reached at woodduck38@gmail.com. Join his conversation about birds at startribune.com/wingnut.