True.
Shivering is a bodily function in response to cold in warm blooded animals/human. When the core body temperature drops shivering reflex is triggered to maintain homeostasis. Skeletal muscles begin to shake in small movements creating warmth by expending energy.
The answer is population!
Different times for differing species, but generally they breed in late winter and give birth in early spring.
A thin layer of protein, within epithelial tissue, that anchors the epithelium to the extracellular matrix is the basement membrane. It separates the epithelium, mesothelium and the endothelium from the connective tissues underneath. It has two layers namely the basal lamina and the reticular connective tissue. Its main function is to anchor the epithilium to the dermis underneath the skin. It would act as a barrier in order to prevent malignant cells in invading tissues that are found deep within. It also important in the process of angiogenesis or the development of blood vessels where it increases the differentiation of the endothelial cells.