In this week's very cold weather it's hard to stay warm but birds have a few strategies that help.
They eat a lot and they also naturally shiver to stay warm. Shivering sounds pathetic but it actually works because the muscles generate heat. The big pectoral (breast) muscles are the best for this.
Some birds shelter in nooks or crannies of hollow trees or on the outsides of our buildings. Look at chimney tops and you'll see starlings absorbing the warm exhaust. On Monday I saw a peregrine at Pitt facing inward at a high window on the Cathedral of Learning. The window was warmer than the surrounding air.
Other birds come indoors. On Monday afternoon Richard Nugent reported he'd found a Carolina wren sheltering in his heated garage as the temperature was heading for -12 degrees that night. What a smart wren! Richard put out food and water for the bird to enjoy while it waited for the weather to improve.
Huddling helps. Inca doves not only huddle sideways as shown above but they make pyramids two or three rows high. According to Ornithology, as many as 12 Inca doves will form a pyramid, fluff their feathers and face downwind in a sheltered sunny place. "In large pyramids, doves exposed on outside positions try for better positions in the top row and cause the whole pyramid to readjust." This sounds like a circus act, amazing to watch.
Last night was the last of the bitter cold. If the birds can make it through today the weather will moderate, then switch to above-normal temperatures this weekend.
Hang in there, little birds. Help is coming soon!