Shelled peanuts are a great winter food for birds since they pack a calorie punch: 412 fat calories in each 1/2 cup serving. And calories provide energy for birds during cold winter days and nights.
First thing in the morning, you'll see these little guys feasting on peanuts, working hard to replenish the calories they burned overnight. And all day long, they pack in the calories, looking for easy, high calorie food sources either at your feeders or in nature.
You'll notice another feeding frenzy just before dark, as birds use the last few minutes of light to gather calories needed to make it through the night. As they huddle up close to a tree trunk or maybe in a roosting box, they puff up their feathers to keep warm. They can lose up to 10% of their body weight on extremely cold nights. Then they're up at first light to start it all over again.
Even birds that don't typically cling well on feeders like the junco below will try to access high-fat peanuts on an especially blustery winter day.
Birds do not rely on our feeders to survive - remember, they've been surviving for centuries before humans ever put out feeders! If you took down your feeders, they'd do just fine.
But providing birdfeeders, including one filled with high energy peanuts, can help their survival by preserving precious calories in a bird's search for food to make it through the winter's day.