The vegetation surrounding a nest shades and insulates the incubating
bird in addition to concealing it. The vegetative material
that makes up a nest insulates the eggs from its warmer or cooler
surroundings. Since a Killdeer builds a stone-lined nest on barren
ground, both egg and adult are subject to...
Winters in north-temperate climates impose high
thermogenic demands upon small birds which are met by
seasonal acclimatization. This thesis investigates the
extent and mechanisms of seasonal acclimatization in darkeyed
juncos (Junco hyemalis) inhabiting western Oregon.
Although insulation is significantly increased in
winter, acclimatization is primarily metabolic. Increased
metabolism is required...
Although endothermy is one of the most significant evolutionary developments in the vertebrates, its origins among extinct taxa have traditionally been difficult to determine. Endothermy is primarily an attribute of the "soft anatomy," and its key features, such as complex lungs, elevated blood oxygen carrying capacity and mitochondrial density, do...
Clothing is the primary means that wilderness backpackers have to protect themselves from injuries and illnesses that can occur while hiking in the cold. The current method of layering clothing may not meet backpackers' needs for both thermal insulation and heat dissipation, particularly in areas of the body that produce...