Nature Notebook

Our winter birds are amazing creatures. Humans rely upon heating systems to stay warm; birds rely upon their bodies. A bird’s “furnace” produces a great deal of heat. The bird’s feathers trap this heat in an insulating layer of air. Fluffed feathers create even more air spaces to hold heat. Birds have 25 to 30 percent more feathers in winter to keep them warm.

Occasionally more heat is needed in the insulating layer, so the bird will shiver. This requires a lot of energy so the bird needs to eat frequently. It will choose food that is richer than its summer diet to obtain extra calories. At night, birds save calories by slowing their metabolism and letting their body temperatures drop. In the morning, they shiver to warm themselves then set off on their never-ending search for food.

Sign up for a Fire Building Class being held this Sunday, Jan. 14 at 2 p.m., to learn how to build the perfect campfire with Sarett naturalist, Dane Rasmussen. Creating a good campfire is an art, and like any art, it requires patience, experience, good supplies, and the right knowledge. Please call to register, 269-927-4832; Member/$5, Non-Member/$8, Children/$3.