Stories by Knut Schmidt-Nielsen

Exchanges between two fluids moving in opposite directions are the basis for a variety of stratagems that enable many species of animal to survive comfortably in an inhospitable environment

The avian respiratory system is different from the mammalian one. The lungs do not simply take air in and then expel it; the air also flows through a series of large sacs and even hollow bones

How does the camel survive for weeks without drinking? Studies in the Sahara Desert have exploded some old legends and have elucidated the animal's remarkably parsimonious water economy

A special organ which eliminates salt with great efficiency enables marine birds to meet their fluid needs by drinking sea water. Similar organs have been found in marine reptiles