hibernaculum

The term hibernaculum (plural hibernacula) derives from the Latin word for thicket or shelter and refers to a place used by organisms as a protected environment during periods of dormancy or hibernation. In ecology, the concept is applied broadly, encompassing natural caves, abandoned burrows, underground burrows, and even man‑made structures that provide stable microclimates, adequate humidity, and protection from predators.

Animals that rely on hibernacula include a wide range of mammals such as bears, bats, ground squirrels, and bats, as well as certain amphibians, reptiles, and invertebrates that undergo brumation or torpor. For mammals, the hibernaculum often offers a cool, relatively constant temperature and reduced metabolic demand, allowing the body to conserve energy while internal physiological processes are down‑regulated. The selection of a hibernaculum is influenced by factors such as depth, shelter integrity, and proximity to food sources that support the post‑hibernation emergence period.

In insects, examples of hibernaculum use include overwintering larvae of buck moths and certain beetle species that inhabit leaf litter or soil cavities. The term is also employed in the context of certain plant species that survive adverse conditions in dormant buds sheltered within leaf litter or bark. In these cases, the hibernaculum functions as a buffer against extreme temperatures and desiccation.

Understanding hibernacula has implications for conservation biology, particularly as climate change and habitat fragmentation alter the availability of suitable sites. Protecting existing hibernacula and creating artificial refugia can mitigate the negative impacts on species that depend on these critical microhabitats for survival during winter periods.