Final answer:
True hibernators like ground squirrels experience significant drops in both heart rate and body temperature, whereas bears enter a deep sleep with relatively stable body temperatures and metabolic rates. Small mammals need to eat during hibernation due to their high metabolic rate and inability to store sufficient fat for the entire winter. Designing experiments to measure both heart rate and body temperature would provide a complete picture of an animal's metabolism during hibernation.
Step-by-step explanation:
True hibernation is characterized by significant reductions in both heart rate and body temperature. Examples of true hibernators are ground squirrels and certain bat species. Unlike these smaller mammals, bears do not undergo true hibernation but instead enter a deep sleep where their body processes do not slow down considerably, and their body temperature remains relatively stable.
Small mammals, such as ground squirrels, need to eat periodically during hibernation because of their high metabolic rate relative to their size. Their small body size cannot store enough fat to last the entire winter without replenishing energy. Conversely, bears have much larger fat stores which support them through the winter months.
To study an animal's overall metabolism during hibernation, scientists can design an experiment to collect simultaneous data on body temperature and heart rate. This dual measurement can offer crucial insights into the metabolic rate of hibernating animals and can be accomplished with today's technology, as outlined at the OpenStax College resource.