Hibernation

When considering some of God’s marvelous creatures, as we have had opportunity from time to time in this rubric, we find that our thoughts always go back to the beautiful twelfth article of the Belgic Confession, in which we make a precious confession regarding God’s work of creation and providence.

We believe that the Father, by the Word, that is, by His Son, hath created of nothing the heaven, the earth, and all creatures as it seemed good unto Him, giving unto every creature its being, shape, form, and several offices to serve its Creator; that He doth also still uphold and govern them by His eternal providence and infinite power, for the service of mankind, to the end that man may serve his God (BC Art. 12a).

Winter is truly a fascinating time of the year. Because winter does not bring the fruit and fullness of spring and summer, God upholds and governs His creation in special ways. Of the many different ways in which God especially cares for the creation during the winter months, we will focus for the purpose of this article on “hibernation.” This phenomenon is particularly fascinating because of the unusual and amazing physiological changes that God brings an animal through during this time.

Hibernation

Hibernation is a state of lethargy that various mammals enter into during the winter months, the goal of which is to conserve energy while fresh food supplies are limited. Ask a child to name an animal that hibernates and likely the response will be “bear.” If hibernation is thought of only in terms of a coma-like state associated with significantly reduced body temperatures, then bears technically would not qualify for “hibernator” status. Mammals such as woodchucks, chipmunks, and squirrels truly hibernate. In hibernation, body temperatures drop, breathing and heart rates lower, and body metabolism slows. For example, a squirrel’s body temperature drops to within a degree or two of the outside temperature. Chipmunks have a dramatic change in heart rate—from 200 beats per minute to 5 beats per minute. These hibernating mammals experience a coma-like state and are not easily awakened. Nevertheless, these animals, like the squirrel for example, must come out of their hibernation every few days in order to urinate and defecate (removing harmful wastes that build up in the body as fat cells are metabolized) and dig up a quick snack from a previously-made cache. This explains why you may have seen squirrels darting around your yard in the dead of winter. They do hibernate, but must break from that from time to time.

Hibernating Bears

Bears, however, differ from other mammals in hibernation. Although a bear experiences a somewhat lower heart rate, its body temperature drops only a little, and it need not awaken to eat or rid itself of wastes. This difference has caused some to suggest that bears are not “true” hibernators. They have attached instead the term “denning” to the activity of a bear. For the purpose of this article we will still refer to the bears as hibernators.

Grizzly bears, for example, hibernate for 5 to 6 months of the year. (By the time this article goes to print, many grizzlies may be coming out of hibernation. Depending on location and the harshness of winter, they exit their dens sometime between March and June). In order to hibernate, grizzlies must amass a great amount of fat during the summer months. In order to do this, they spend most of their time searching for food and eating it. Grizzlies obtain 80 to 90 percent of their food from vegetation and insects. Their diet consists mostly of berries, nuts, plant roots or bulbs, and sometimes insects or their larvae. Some grizzlies, in Alaska and the west coast of Canada, have access to salmon, which serve a large place in their diet.

Once bears have obtained sufficient winter reserves, they retreat to a den to hibernate. Although their heart rate drops to one-fifth of its normal rate, and their oxygen usage is half of its normal rate, their body temperature drops only a few degrees. Therefore, bears do not fall into a coma-like state as the chipmunk and squirrel do, in which state one could mistake the creature for dead. Their regular body temperature keeps bears in a somewhat “active” state—in which they could readily attack enemies if prematurely awakened. Because of this, in heart rate—from 200 beats per minute to 5 beats per minute. These hibernating mammals experience a coma-like state and are not easily awakened. Nevertheless, these animals, like the squirrel for example, must come out of their hibernation every few days in order to urinate and defecate (removing harmful wastes that build up in the body as fat cells are metabolized) and dig up a quick snack from a previously-made cache. This explains why you may have seen squirrels darting around your yard in the dead of winter. They do hibernate, but must break from that from time to time.

Hibernating Bears

Bears, however, differ from other mammals in hibernation. Although a bear experiences a somewhat lower heart rate, its body temperature drops only a little, and it need not awaken to eat or rid itself of wastes. This difference has caused some to suggest that bears are not “true” hibernators. They have attached instead the term “denning” to the activity of a bear. For the purpose of this article we will still refer to the bears as hibernators.

Grizzly bears, for example, hibernate for 5 to 6 months of the year. (By the time this article goes to print, many grizzlies may be coming out of hibernation. Depending on location and the harshness of winter, they exit their dens sometime between March and June). In order to hibernate, grizzlies must amass a great amount of fat during the summer months. In order to do this, they spend most of their time searching for food and eating it. Grizzlies obtain 80 to 90 percent of their food from vegetation and insects. Their diet consists mostly of berries, nuts, plant roots or bulbs, and sometimes insects or their larvae. Some grizzlies, in Alaska and the west coast of Canada, have access to salmon, which serve a large place in their diet.

Once bears have obtained sufficient winter reserves, they retreat to a den to hibernate. Although their heart rate drops to one-fifth of its normal rate, and their oxygen usage is half of its normal rate, their body temperature drops only a few degrees. Therefore, bears do not fall into a coma-like state as the chipmunk and squirrel do, in which state one could mistake the creature for dead. Their regular body temperature keeps bears in a somewhat “active” state—in which they could readily attack enemies if prematurely awakened. Because of this, would desperately love to replicate such a recycling process in the human body).

By these amazing biological changes, a grizzly bear will hibernate throughout the winter months in order to conserve necessary energy. God, in this way, provides for the survival of the bear while the vast food supplies are unavailable during the harsh winter months.

Providence

As we have seen with so many other creatures, so we see again the marvelous design of God. We are impressed with God’s wise provision for all His creatures. Scientists estimate, based on grizzly scats, that a single grizzly in the Yukon may eat up to 200,000 soapberries in one day. When we consider the number of berries, moths, insects, larvae, fish, and other nutrient-rich foods that a single grizzly must consume in order to live throughout the year, we stand amazed at God’s bountiful provisions. And that is just for one bear out of many, and one species out of many. Our good God, the Creator and Sustainer of all, provides for all His creatures, including us. Therein is great comfort! “These all wait upon thee: that thou mayest give them their meat in due season. That thou givest them they gather: thou openest thine hand, they are filled with good” (Ps. 104:27-28).

We are reminded that God, in providing creatures their food, must so govern all things in order that the food may grow and be available. For a grizzly to eat 200,000 soapberries in a day, there must have been the right rainfall, sunshine, and warmth for those berries to grow. For a grizzly to obtain salmon, the salmon, in God’s wise plan and direction, must spawn, and there-fore pass through the rivers in high numbers, in part, so that the grizzlies may feast. While this fish “migration” is necessary for the salmons’ own reproductive purposes (to be able to sustain its population), the large number of spawning fish at the same time provides also abundant food for another of God’s creatures. So it is throughout the creation. God wisely directs all things—rain, atmospheric temperature, carbon-dioxide levels, and so forth, in order that food may be prepared for all His creatures. May we rejoice in our all-wise, sovereign God!

Finally, we must be reminded that God has given to each creature the exact anatomical and physiological features needed to survive and live where He places them. For the bear to survive it must have a metabolism that changes from summer to winter in order to hibernate as it does. The difficulties of winter-life necessitate a period of hibernation. This period of hibernation and the appropriate metabolism, God gives, in His wise design, to each bear. May we learn, from this, to have great peace in our lives—in plenty and in want; in happiness and in sorrow—knowing that the great God of creation is our loving Father. He who provides for all creatures throughout the seasons of their lives is able and willing even more so to equip and provide for us, His covenant people. God is for us—of whom shall we be afraid? Who or what can be against us? Praise God for His wondrous works, and trust in Him. He will provide exactly what we need to serve Him in this life and in the next!