Effects of Seasons on Animals Animals that cannot avoid seasonal changes in temperature have adaptations that allow them to compensate and acclimatize to the changes. For example, a fish's metabolism will undergo metabolic compensation and change its metabolic rate to compensate for seasonal temperature changes. Metabolic compensations adjust the metabolic reactions to counter the effects of temperature. One way to accomplish this is to have different sets of enzymes. For survival, animals will attempt to maintain their body temperature near an optimum.
Homeotherms maintain a fairly constant body temperature.
Mammals and birds are homeotherms. Poikilotherms do not maintain a constant body temperature and are more often influenced by environmental temperatures. Most animals that are not mammals and birds are poikilotherms. Heterotherms maintain a constant body temperature some of the time and are influenced by ambient environmental temperatures at other times. Hibernating animals can be considered heterotherms.