Winter 2014 by Kristi Niekamp and Miranda Smith Most of us know how groundhogs spend the winter. They find a cozy den and go into hibernation. What about the critters under the Pennsylvania Fish & Boat Commission's jurisdiction? How do reptiles, amphibians and fish survive the winter? Snakes, turtles, frogs, toads and fish are often called "cold-blooded," but the technical term is ectothermic. Humans are endotherms and (Watch for these words!) burn much energy to * Ectotherms - also known as cold-blooded, body temperature keep their body heat varies with the environment within a narrow range. * Endotherms - also known as warm-blooded, metabolism We sweat when it is used to maintain body temperature hot and shiver when * Freeze tolerant - species that can survive freezing it is cold. Ectotherms * Freezing point - the temperature at which a liquid freezes. do not do these things The freezing point of water is 32-degrees F (0-degrees C). and use less energy * Frost line - maximum depth of ground where the soil since they can function freezes in the winter in a much wider range * Hibernaculum - place where an animal hibernates during of temperatures. the winter They have physical or * Hibernation - the practice of certain animals to remain behavioral adaptations dormant (or inactive) throughout the winter, metabolism that allow them to slows down survive these extremes. * Hypothermia - lowering of body temperature Let's explore how these * Metabolism - the processes occurring within an organism animals survive the that are necessary for life (some substances are broken cold winter months. down or converted to energy) Vocabulary PFBC website: www.fishandboat.com Pennsylvania Angler & Boater * January/February 2014 45