Chapter 48, Problem 1CT

Summary Introduction

To explain: The reasons why melting of snow in the arctic pose a hazard for arctic hares.

Concept introduction:  Melatonin is secreted by the pineal gland only during periods of darkness and encourages sleep, thereby helping to set the internal clock inside the body. The level of melatonin influences the timing of seasonal coat color changes in hares. Due to the effects of melatonin, a hare sheds its dark fall coat as its white winter coats grows in. This white coat of the hares helps them to camouflage in the snow.