{"id":44909,"date":"2025-06-01T15:25:11","date_gmt":"2025-06-01T19:25:11","guid":{"rendered":"https:\/\/news.maryland.gov\/dnr\/?p=44909"},"modified":"2025-06-20T15:51:37","modified_gmt":"2025-06-20T19:51:37","slug":"estivation-a-midsummers-nap","status":"publish","type":"post","link":"https:\/\/news.maryland.gov\/dnr\/2025\/06\/01\/estivation-a-midsummers-nap\/","title":{"rendered":"Estivation- A Midsummer’s Nap"},"content":{"rendered":"

by Sarah Witcher<\/strong><\/em><\/p>\n

\u201cAh, summer, what power you have to make us suffer and like it.\u201d ~Russell Baker<\/span><\/em><\/p>\n

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An Eastern box turtle cools off in the water, by Rebecca Bailey, 2023 DNR Photo Contest<\/p><\/div>\n

Imagine that you are a box turtle. You slowly meander through woods and backyards, in search of water and snacks.\u00a0The dappled browns and oranges on the top of your shell (your carapace) blend seamlessly with the dried leaves and speckles of unrelenting sunshine streaming through the trees, making you almost invisible to onlookers.\u00a0<\/span><\/p>\n

It\u2019s been oppressively hot for weeks, and the blood in your veins feels like dried up nail polish, sticky and sluggish.\u00a0Speaking of slugs, you eat one off the bottom of a leaf, but it\u2019s no use – you still feel thirsty. By midafternoon the heat is triggering an instinct you didn\u2019t know you had; you are getting very sleepy. Slowly and methodically, you dig a shallow depression under the cover of jewelweed and a tenacious blackberry bramble. You settle in against the cooling soil, close your eyes, and wait.<\/span><\/p>\n

A Maryland summer can almost always be relied upon to bring relentless heat and humidity. For those of us who don\u2019t love the heat or who have to work in it, those days can bring to mind fantasies of escape, like wishing you could take a nap and wake up when the heat is gone!\u00a0Unfortunately for humans, we are stuck in circadian rhythms and bodies that need near-constant feeding and watering to survive even a few days. Our fragile physiology can usually maintain the constant sub-100-degree temperatures we need to thrive, but we are notoriously susceptible to damage from exposure and extreme temperatures.\u00a0This forces us to flee summer heat in the shade or the air conditioning rather than lean into the swelter.<\/span><\/p>\n

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American Toad. Photo by Jordan Kron<\/p><\/div>\n

Most of us have heard of hibernation, a prolonged period of dormancy to escape cold temperatures, but did you know there\u2019s a version of that for the heat?\u00a0Fortunately, quite by design, several Maryland animals have figured out a lower-tech solution than swimming pools and forced air systems: it\u2019s called <\/span>estivation <\/b>( from <\/span>aestas<\/span><\/i>, the Latin root word for summer). <\/span>Like hibernation<\/span><\/a>, it\u2019s not <\/span>simply<\/span><\/i> a behavior modification like choosing to sleep. Metabolic rates actually dramatically decrease, slowing or even halting some chemical processes that consume energy. This isn\u2019t just to beat the heat for increased comfort! The decrease in metabolism can be between <\/span>70-100%<\/span><\/a> of the normal rates in some animals, and it proves to be an essential survival strategy in times of food shortage and drought.<\/span><\/p>\n

It’s easy to understand how animal residents of deserts and other arid climates might need to estivate as a survival strategy. While Maryland\u2019s heat index may be less harsh, we still have a few species that utilize estivation \u2013 a tactic that may serve them very well as our global climate changes. Reptiles and amphibians are our best-known summer snoozers. Here are a few examples:<\/span><\/p>\n