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Surviving the Scorch – How Animals Beat the Heat

When it comes to beating the heat, animals have their own quirky playbook.

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Unlike most animals, horses sweat to keep cool in the heat, using their unique ability to regulate body temperature and stay cool during hot summer days.

Photo by Eric Fowler, Nebraskaland Magazine

By Monica Macoubrie, Wildlife Education Specialist

Imagine being a furry creature in Nebraska during the peak of summer — it’s like wearing a winter coat in a sauna! While we humans crank up the AC, sip iced tea and lounge in front of fans, wildlife must get creative to beat the heat. Picture a prairie dog retreating to its underground burrow or a jackrabbit flashing its oversized ears like a pair of built-in fans. From playing hide-and-seek with the sun to inventing their own versions of natural air conditioning, animals have some quirky ways to stay cool.

Sweating

Sweating is one of nature’s most effective cooling strategies, though it looks differently across animal species. In mammals like humans, horses and some primates, sweat glands are distributed across the skin, allowing for efficient heat dissipation through the evaporation of sweat. When the body’s internal temperature rises, these glands secrete a salty liquid that cools the surface of the skin as it evaporates. Horses, for instance, have a high density of sweat glands, and their sweat contains a protein called latherin, which helps spread the sweat more effectively over their body, which enhances cooling.

In the insect world, some species exhibit a form of “sweating” through the secretion of fluids that help regulate body temperature.

Panting

Other mammals rely on panting. While energy-intensive, panting is an essential adaptation that enables many species to survive and remain active even in scorching conditions. Dogs and cats, for example, have a limited number of sweat glands located primarily on their paw pads, which are insufficient for whole-body cooling. Instead, they rely on panting to regulate their temperature.

When an animal pants, it rapidly inhales and exhales through its mouth, increasing airflow over the moist surfaces of the tongue, mouth and upper respiratory tract. This process promotes the evaporation of saliva and moisture, which in turn cools the blood circulating through these areas and helps lower the animal’s overall body temperature. In dogs, this rapid breathing rate can be 10 times faster than normal, significantly enhancing cooling efficiency.

When a dog pants, it sticks out its tongue and breathes quickly, facilitating evaporation and heat exchange. Photo by Jenny Nguyen-Wheatley, Nebraskaland Magazine.

Although cats primarily rely on grooming and seeking shade to cool down, they will pant in extreme heat or after vigorous activity. Their panting is less efficient than that of dogs, so they use it as a supplementary cooling method. Smaller mammals, such as rodents, also pant, but their small size allows them to dissipate heat quickly through rapid breathing.

Reptiles, including lizards, utilize a form of panting called buccal pumping, where they rapidly move air in and out of their throat to cool down. Although this method is less efficient than in mammals, it is critical for thermoregulation in hot environments.

Wallowing

Interestingly, some animals, such as pigs, have few functional sweat glands. Instead of sweating, pigs wallow in mud, which not only cools them down as the mud evaporates but also protects their skin from sunburn.

Defecation

In the animal kingdom, using feces as a cooling strategy might sound unusual, but it’s a clever and effective method for some species. One fascinating example is that of the turkey vulture. Like many birds, turkey vultures practice a behavior known as urohidrosis, meaning they defecate on their legs for thermoregulation. As the liquid in their feces evaporates, it cools the blood vessels in their legs, helping to reduce their body temperature in hot weather.

The adaptation is particularly effective for turkey vultures because they often soar at great heights where temperatures can be extreme. By applying their own droppings to their legs, they exploit evaporative cooling, a process akin to sweating in mammals. It allows them to maintain optimal body temperatures even during prolonged flights in the heat, ensuring they can efficiently search for carrion without risking overheating.

Like many birds, turkey vultures practice a behavior known as urohidrosis, where they defecate on their legs. As the liquid in their feces evaporates, it cools the blood vessels in their legs, helping to reduce their body temperature in hot weather. Photo by Justin Haag, Nebraskaland Magazine.

Estivation

Most of us have heard of animals hibernating to survive extremely cold conditions. However, there’s another survival tactic known as estivation, which is when animals “sleep” through blazing temperatures. Estivation involves a series of physiological adjustments aimed at minimizing water loss and reducing metabolic activity, thereby lessening the need for resources during periods when vegetation, water and prey are scarce.

Certain creatures, such as certain snails, estivate to avoid dehydration by retracting into their protective shells. Many species of earthworms employ this strategy after coming to the surface after a rainstorm. Numerous studies have shown that earthworms can survive for weeks at a time in drought-ridden areas thanks to estivation.

Reptiles and amphibians employ estivation as a critical adaptation to survive harsh environmental conditions, particularly in arid regions or during dry seasons. When faced with extreme heat and limited water availability, these animals retreat to burrows, underground chambers or sheltered areas where they can conserve moisture and energy.

During extreme heat, prairie dogs enter a state of estivation, slowing down their metabolism and activity to conserve energy and survive harsh conditions. Photo by Jeff Kurrus, Nebraskaland Magazine.

Many snake species in Nebraska, such as the speckled kingsnake and the plains blackhead snake use this strategy to escape the harsh summer sun during the summer. Amphibians such as frogs may bury themselves in moist soil or mud, slowing their heart rates and becoming less active to conserve energy. By entering estivation, reptiles and amphibians not only survive the challenging conditions but also synchronize their life cycles with seasonal changes, ensuring they emerge when environmental conditions become more favorable for feeding, growth and reproduction.

Ears

Jackrabbits, particularly the desert-dwelling species such as the black-tailed jackrabbit, cope with the intense heat of their habitats, such as the Sandhills of Nebraska, using their large ears for thermoregulation.

Blood vessels close to the skin’s surface in the ears expand, allowing increased blood flow. As blood circulates through the ears, heat from the body dissipates into the air through a process called convection. Additionally, the large surface area of the ears, which can be up to 6 inches long, enhances this cooling effect by maximizing heat exchange with the surrounding air. This adaptation helps jackrabbits avoid overheating and dehydration during the scorching daytime hours, enabling them to remain active and to forage for food.

White-tailed jackrabbit. Jackrabbits stay cool in the heat by using their large ears, which are filled with blood vessels that release excess body heat and regulate their temperature.  Photo by Justin Haag

Throat Vibrations

For animals that can’t sweat, avoid defecating on themselves, don’t choose to estivate or lack ear-based thermoregulation, there is gular fluttering. This method is employed by many birds, which essentially involves rapidly vibrating the muscles and bones in the throat to stay cool. Types of birds that use this strategy in Nebraska include pelicans, herons, doves, owls, quail and nighthawks.

Unlike many birds that rely on panting to cool themselves, owls, with their relatively larger bodies and reduced ability to pant effectively due to their anatomy, have developed gular fluttering as an efficient alternative. They rapidly vibrate the throat (gular) region, specifically the thin, flexible skin located beneath the beak. This action creates turbulence in the air passing over the moist surfaces of the mouth and throat, enhancing evaporative cooling.

An adult burrowing owl. Owls will perform gular fluttering during extreme heat—a rapid movement of the throat muscles that helps them cool down by increasing evaporative heat loss. Photo by Justin Haag.

This adaptation is particularly advantageous for owls living in diverse habitats ranging from hot deserts to humid forests, where maintaining an optimal body temperature is essential for survival and hunting efficiency. By using gular fluttering, owls can regulate their internal heat levels without expending excessive energy or compromising their ability to remain alert and vigilant during nocturnal activities.

When it comes to beating the heat, animals seem to have their own quirky playbook. From the dignified elegance of owls fluttering their gulars to the less glamorous strategy of defecation in turkey vultures, from retreating into shells to strategically timing periods of reduced activity, these adaptations remind us that survival sometimes means thinking outside the icebox.

So, next time you’re sweating under the sun, take a moment to appreciate the wild and wonderful ways our furry and feathered friends keep cool — they might just inspire your next heatwave survival tactic!