| 1 | Coachwhip |
Maximum length: 259.1cm.
The coachwhip is a non-venomous snake found across virtually the entire US south, from Florida in the east to California in the west. This species is renowned for its blisteringly fast speeds, and another of their skills is resistance to hot weather. More than any other US snake, the coachwhip can be found patrolling dusty plains, semi-deserts, wooden porches, and dry cattle fields at temperatures far beyond comfortable.
Coachwhips generally appear in open areas with little shelter. They act aggressively if handled by humans, and are exclusively diurnal, with nocturnal movements being vary rare. Their resistance to hot weather is purely strategical, as over 60% of their diet consists of lizards, such as Texas horned lizards.
Specifically, coachwhips search for active lizards darting quickly between cacti and rocks, unlike other reptile-hunting snakes, which seek out sleeping lizards in their dens. Lizards generally cope with more extreme heat than snakes, therefore giving the coachwhip a strong evolutionary incentive to withstand scorching days themselves.
As hunters, coachwhips are also highly reliant on eyesight. A scaly tail disappearing behind a creosote bush is all they need to get excited. The hotter the day, the more other snakes are hiding in dark burrows, the less competition coachwhips will have for these meals.
| 2 | Coin-marked snake |
Maximum length: 140cm.
One of the most common non-venomous snakes of Israel. The coin-marked snake (Hemorrhois nummifer) is a species of Mediterranean shrubland and olive groves, which has viper-mimicking patterns, and an intimidating ability to triangulate its head.
Coin-marked snakes are slow-moving compared to coachwhips, but are similar in their diurnal nature, and resistance to extreme temperatures in which most other snakes flee. Even on the hottest, most scorching days, when most Israeli citizens are hiding indoors, coin-marked snakes move steadily through the countryside, searching olive groves for small rodents.
Compared to their Israeli neighbours, coin-marked snakes are the most faithful to daytime regardless of heat. Palestinian vipers are fully nocturnal, as are Field’s horned vipers. Both vanish into dark burrows to avoid the hottest temperatures. Diadem snakes are diurnal, but become nocturnal during summer, as they literally can’t take the heat.
Meanwhile, coin-marked snakes never become fully nocturnal. The most they become is crepuscular, AKA active during dawn and dusk, during the absolute hottest days. With a complete lack of venom or vicious teeth, this heat resistance is one of their greatest advantages.
| 3 | Moila |
Maximum length: 150cm.
The moila (Malpolon moilensis) is a snake of North Africa and the Middle East, which is relatively isolated on the evolutionary tree. This species has evolved unusual abilities such as flaring a neck hood to mimic the Egyptian cobra, and rubbing a strange waxy secretion into their scales using their nose.
Moilas average at 60-80cm, and also possess the gift of high heat resistance. This is an exclusively diurnal (day-faring) snake, and in the hazy deserts of Ethiopia or Morocco, this is a very risky characteristic to have. Any snake which misjudges its core body temperature can fall victim to the one thing snakes fear above all else: going crispy.
Somehow though, this doesn’t seem to be a problem for moilas. On the hottest days, they can stride through rocky canyons, dry grazing fields and stony semi-deserts long after other snakes have given up.
Moilas are moderately venomous, although the exact toxins are poorly researched. They’re a widespread species, ranging from Mauritania in the far west to Iran in the far east, and it’s possible that their high heat resistance is one reason why. Despite being common, this is still a relatively mysterious snake.
| 4 | Yellow-faced whipsnake |
Maximum length: 100cm.
Australia is a competitive place for a snake to live, and the yellow-faced whipsnake falls short in several ways. Their venom can cause moderate swelling, but is dramatically weaker than a tiger snake’s. There’s only a few neurotoxins, which fail to progress to full-blown paralysis. But yellow-faced whipsnakes do have one undisputed advantage over other Australian snakes, and that’s heat resistance. The ability to exist in scorching climates without having to flee underground.
A 2003 study compared this species to 3 Australian neighbours: the marsh snake, golden-crowned snake, and small-eyed snake. The latter two were fully nocturnal, and the marsh snake a mixture.
Meanwhile, the yellow-faced whipsnake moved mainly from 10:00-15:00, not even resting during peak sunlight. They were also active at by far the highest body temperatures: 31.3-33.2C. The other three were active at body temperatures of 18.1-23.4C.
Yellow-faced whipsnakes are fast-moving and have a high metabolism, both of which have a correlation with high heat resistance. You can find this species on the east coast of Australia, in roasting shrubland, town alleyways, grassland and backgarden swimming pools alike.
| 5 | Paraguay green racer |
Maximum length: 160cm.
The Paraguay green racer (Philodryas nattereri) is the the dominant maniac snake of eastern Brazil, inhabiting the dry Caatinaga region. Despite their name, they only have a slight foothold in Paraguay to the south. Their daily exploits include climbing rooftops, stealing nestlings from birds’ nests, and getting beaten to death by 30-member capuchin monkey troops wielding fallen tree branches (this was actually observed in 2016).
Paraguay green racers have only a mild venom , but they compensate with a great advantage: being one of South America’s most heat resistant snakes. This snake is purely diurnal, as a 2011 study found that they moved exclusively from 07:00 to 16:59. Their activity was most concentrated in the hottest hours of the day: 11:00-12:59.
Paraguay green racers also favour open ground, which makes their heat resistance all the more impressive. They inhabit swaying tree clumps, but also open cerrado grassland and dirt roads.
Similarly to a coachwhip, lizards form 60-70% of their diet, including the likes of Peter’s lava lizards and whip-tailed lizards. Lizards favour high heat, and to successfully lunge and grab them, the Paraguay green racer has evolved to be similar.
| 6 | Cape cobra |
Maximum length: 231cm.
A neurotoxic snake of southern Africa, which causes many deaths annually. This species varies from yellow to brown to red, and generally prefers open areas such as shrubland and grassland.
The cape cobra (Naja nivea) has some of the greatest heat resistance of any venomous snake, outside of actual desert snakes like the sidewinder. The sun barely suppresses them; in fact, it seems to make them more energetic. Some of their most famous videos have been shot in sun-drenched savannahs at midday, including their infamous battles with honey badgers and mongooses (which they often lose).
The story doesn’t change with human encounters, as cape cobras are more than willing to lunge and envenomate on the hottest days. Luckily, their liking for open environments makes them relatively easy to spot.
Cape cobras don’t care about the beating sun one bit, and will purposefully slither around at mid-day when others snake are hiding. When they do need to cool off slightly, cape cobras will slither into underground mammal burrows, sometimes eating the occupants (which sometimes escape).
| 7 | Karoo sand snake |
Maximum length: 100cm.
This fast, darting snake lives in western Namibia and far western South Africa. The Karoo snake snake (Psammophis notostictus) is mainly found in dry shrubland and arid semi-deserts, where they face scorching temperatures from the moment the sun rises. Somehow though, this doesn’t seem to bother them.
Karoo sand snakes move by day, and are able to withstand even the hottest of Africa days, when even air con isn’t enough and weirdly distorted elephants seem to appear over the horizon in a hazy mirage. They lose no energy during hot weather, and can be seen darting around as rapidly as ever.
Karoo sand snakes are harmless, with only a mild venom. They’re mostly pale brown, with occasional orange patches on their flanks. Karoo sand snakes don’t just cope with hot weather because of physiological resistance, but because of their ability to seek out small parcels of shade, under shrubs, bushes or rocks.
Karoo sand snakes tend to dart around rapidly, but then suddenly come to a standstill for several minutes, allowing their rapidly rising body heat to escape into the atmosphere. While they’re 90% focussed on hunting lizards, there’s always 10% at the back of their mind thinking about the next shady bush.
| 8 | Spotted desert racer |
Maximum length: 94cm.
The deserts of Iran are not a hospitable place to live. Temperatures break through 40C with ease, and every hour brings the hot sands and crumbling ruins of old Persian fortifications to sizzling new heights. The snakes that do survive here generally resort to being nocturnal, fumbling around only at night. But not the spotted desert racer. This species has a mild venom, and primarily hunts lizards, which they catch using rapid pursuit.
Places you’ll encounter a spotted desert racer include dry hillsides, semi-deserts, and parched steppe at up to 2500 metres. This snake has a great ability which few others can boast of: the ability to slither through burning plains while other snakes cower in their shelters. While other snakes shut down for the day, praying for the sun to set, spotted desert racers can stay active for far longer.
Spotted desert racers are agile, and difficult to catch. They range from Turkey in the far west to Kyrgyzstan in the northeast, covering Iran and Iraq inbetween. This is a diurnal (day-faring) snake, and during summer, they might be one of the few creatures you’ll find on the surface full stop.
| 9 | Horseshoe whipsnake |
Maximum length: 185cm.
The concept of the siesta was invented in Spain. The Portuguese grabbed most of the Atlantic coast before the Spanish realised the refreshing, cooling effect the ocean had, and hence, the interior of Spain is not a pleasant place to be during high summer. Humans aren’t alone in retreating indoors at mid-day, as the vast majority of snakes seek dark shelters, but the horseshoe whipsnake doesn’t seem to care at all about hot weather. Of all Spanish snakes, it’s the one most resistant to high temperatures.
Horseshoe whipsnakes (Hemorrhois hippocrepis) often exceed 1.5 metres, and are completely non-venomous. Not only are they diurnal, but they favour open ground, with very little shade. They shun forests, and stick to dry fields, dusty village entrances and tarmac roads sucking up sunlight.
Horseshoe whipsnakes live in a perfect storm for temperatures to burn them to a crisp, yet they cope remarkably well. They can be found slithering freely around the countryside on hotter days, in full view of tourists.
Horseshoe whipsnakes seem to follow the coachwhip formula: they’re fast-moving pursuit predators, with strong eyesight, and a taste for fast-moving lizards. In every continent, this combination seems to lead automatically to high heat resistance.
| 10 | Common keelback |
Maximum length: 100cm.
The common keelback lives in the marshes, ponds and swamps of Queensland, Australia. They’re a slightly venomous, but harmless species which preys on amphibians such as ornate burrowing frogs, by gathering close to where frogs congregate.
Common keelbacks aren’t quite as heat tolerant as a yellow-faced whipsnake, as during the hottest summer spells, they switch from being diurnal (their preference) to nocturnal. However, they have one of the coolest studies conducted on them. A 2012 survey examined the activity of common keelbacks at various temperatures. Hot weather of 35C had no effect on them. They darted around their ponds, hunting for frogs as usual, and ducking far below when their serpent eyes made out the vague shape of a human.
They were highly heat tolerant, yet when temperatures fell to below 20C, the common keelbacks completely halted. They stopped moving entirely, with no resistance to chilliness.
A common keelback would die rapidly if it tried to live a European adder’s lifestyle, on alpine slopes in Switzerland below cablecars. Alternatively, it would do well if dropped into a Brazilian swamp, if its innate fear of Australian crocodiles carried over to the black caimans patrolling the Amazon. Cool weather might explain why one Queensland marsh which is normally bustling with snakes is suddenly empty of them one chilly morning.