With spring dawning, temperatures will begin to rise and food sources will become more abundant than in the winter. As a result, we’ll see bats, hedgehogs and larger animals like bears emerging from their months-long hibernations.

The science behind hibernation has prompted many, including researchers, to consider the possibility of human hibernation. From astronautical research that could promote space travel to restful mindfulness for self-care, there’s been plenty of speculation regarding the potential benefits of human hibernation. A recent study of half-a-million-year-old fossilized remains found in Spain suggests that early humans did hibernate, spurring further considerations of human hibernation today.

For other animals, human understanding of the physiological aspects of hibernation is important for survival, especially as winters continue to get warmer and human–animal proximity intensifies.

In this article, we’ll look at how hibernation-related studies can inform new approaches to therapeutic interventions in certain medical contexts. We’ll also look at why understanding hibernation is crucial to bettering human–animal relationships.

Understanding hibernation

Briefly, hibernation is a state of dormancy that certain animals enter during winter. It is similar to a process called torpor, though the two differ in terms of length of time and an animal’s level of alertness. During hibernation, animals adjust their internal temperature to match ambient conditions—this can mean dropping body temperature to as low as 0° C.

In entering hibernation, animals are typically responding to unfavorable environmental conditions including lower temperatures and food scarcity. Metabolic changes and reduced body temperature are the two main mechanisms by which animals respond to such changes, requiring stores of energy to be built up in the preceding months. A process similar to hibernation occurs in warmer climates during summer, but the term for this is estivation.

Both processes require tremendous amounts of energy and preparation. Because animals are expending huge amounts of resources to survive for long periods of dormancy, they need to store up excess layers of fat. Notably, the edible dormouse can grow to triple its body weight before entering hibernation, which lasts up to 11 months.

Can hibernation research aid in medical advances?

Understanding the benefits of hibernation behaviors, namely lowered temperatures, as well as other factors including the maintenance of musculoskeletal integrity could help to develop therapeutic treatments for diseases affecting humans today.

Maintaining muscle during hibernation inactivity

Impressively, animals don’t lose much muscle mass despite their prolonged dormancy. Brown bears, for example, who lose up to 30% of their bodyweight during hibernation, experience relatively low muscle wasting, known as atrophy.

A study published in Antioxidants looks at links between oxidative stress and muscle atrophy, and the processes that prevent this from happening in hibernating brown bears. The authors acknowledge that while there are other mechanisms by which bears resist muscle atrophy during hibernation, internal changes to the balance of oxidants and antioxidants contributes to reduced muscle atrophy. More research on the topic could help guide therapies for human patients experiencing muscle atrophy due to a variety of medical reasons including sarcopenia.

They also note that understanding the oxidant–antioxidant balance can be useful in the development of targeted therapies during periods of muscle disuse or under microgravity conditions. Translating our understanding of the way animals protect themselves during hibernation to medical contexts for human patients will hopefully open up new possibilities.

Lowering body temperature

Lowering body temperature can help to maintain a thermal equilibrium between animals and their environment, thereby reducing heat loss and the amount of energy needed for thermoregulation.

The extent to which animals lower their temperature varies. Bears, for example, only need to drop their temperature by about 10° C; other animals such as the Arctic ground squirrel can drop their internal temperature by more than 30° C. Harsher climates can necessitate more extreme drops in body temperature.

But could this well-regulated behavior prove useful for human therapies?

The answer is probably yes. Today, targeted temperature management is useful for treating heart attack, and similar therapies for stroke patients are being developed. Thus, regulating body temperature and altering metabolic states through induced torpor represent promising therapeutic strategies that could be usefully mainstreamed across medical contexts.

Human–Animal proximity during and following hibernation

The work mentioned above seeks to understand whether we should and how we might induce hibernation-like behaviors in humans. However, hibernation in animals is induced naturally in response to environmental conditions and according to their circannual rhythm. As such, animals are able to bring themselves out of hibernation according to need.

It’s important to note that the energy costs placed on animals when brought out of their hibernation state too early can be fatal. This is especially important to keep in mind when encountering animals that hibernate in or close to human habitats. Greater awareness of this is crucial to protecting wildlife and humans.

Additionally, continued urbanization and warmer winters are impacting the natural environment in various ways. One example that has caused concern lately is the early emergence of bears from hibernation due to warmer winters. This has led bears to travel further afield, including to cities and villages, to access food which is vital to ensuring bear cubs make it through to spring.

The factors bringing humans and animals closer together require from us new conceptions of how to manage human–animal relationships to ensure safety and in the interest of conservation.

More-than-human urban design and multispecies justice

To tackle challenges like those mentioned above, researchers are attempting to develop new frameworks that can help to promote safety in and improve human–animal relationships near and within urban environments.

An interesting study published in Sustainability looks at the concept of multispecies justice and how it could help us to adapt human-made environments into ecological habitats. Multispecies justice seeks to center the experiences of both humans and nonhumans. New approaches like this to conservation and human–animal relationships can be useful to achieving some of the aims of Sustainable Development Goal (SDG) 15, including halting biodiversity loss.

The authors suggest weaving conservation knowledge into urban design. Animal-aided design, which involves including considerations for wildlife when planning city greenscapes, is an example of this. More-than-human urban design goes further than conceptions like biophilic design, which simply modify human spaces by incorporating natural elements such as plants, to help reduce the risk posed by humans to animals and vice versa.

The effects of contemporary problems such as climate change—which is bringing about warmer winters—and increased urbanization in relation to hibernation also deserve further study.

Pursuing hibernation research

Collecting data on hibernating animals is a difficult process. It can be challenging to locate hibernation nests, roosts or dens in animals’ natural habitats; additionally, there’s always the risk of disturbing animals and bringing them out of hibernation early.

The research explored here is, however, useful for developing greater insight into hibernation mechanisms. It is also crucial to understanding how human–animal relationships can be fostered, especially for animals that live in close proximity to humans.

To read more about this topic and the animals mentioned in this post, you can visit MDPI’s variety of journals to view leading Open Access research.