estive

Estive is a term used in biology and general usage to describe summer-related matters. As an adjective, it means relating to, occurring in, or suitable for summer. As a verb, estive means to undergo estivation, a state of prolonged dormancy adopted by some animals during hot or dry periods to conserve water and energy. The word derives from Latin aestivus, from aestus “summer.”

In biology, estivation is a physiological and behavioral strategy distinct from hibernation. During estivation, metabolic rate drops, activity slows, and animals seek cool, moist or sheltered microhabitats such as burrows, leaf litter, mud, or inside shells. The duration varies with climate and species, from days to several months. Some animals may reduce water loss through mucus coverings, hardened outer layers, or by sealing entrances to their shelters.

Organisms that estivate include a range of terrestrial mollusks like land snails, various amphibians such as frogs and toads in some regions, desert reptiles including certain lizards and turtles, and several invertebrates such as earthworms and arachnids. In many cases estivation helps these organisms survive extreme heat, drought, or food scarcity common in summer.

Estivation is related to, but distinct from, other forms of dormancy such as diapause and hibernation. It is most commonly associated with hot, dry environments and is considered an adaptive strategy for conserving water and maintaining physiological stability when activity outside is detrimental.

See also: hibernation, dormancy, diapause, arid-adaptation.