The deceptively cute Gray Jay is one of the most intrepid birds in North America, living in northern forests year-round and rearing chicks in the dark of winter. Highly curious and always on the lookout for food, Gray Jays eat just about anything, from berries to small animals. They may even land on your hand to grab a raisin or peanut.
A thermal insulator is something that prevents heat from moving from one place to another. There are 3 main ways that heat can travel: convection, conduction, and radiation. Typically the phrase 'thermal insulator' refers to a material that blocks conduction.
Materials that are poor conductors of heat are called insulators. Air, which has a conduction coefficient of .006, is an exceptional insulator because it is capable of being contained within an enclosed space. This is why artificial insulators make use of air compartments, such as double-pane glass windows which are used for cutting heating bills.