| 1 | Baja California coachwhip |
Probably the most commonly sighted snake in Baja California by ordinary people. Masticophis fuliginosus belongs to the same family as the US coachwhip (a notoriously fast snake). It’s a non-venomous snake, yet highly alert and ready to bite interlopers.
This species is found all over Baja California, from north to south, and crosses the border into San Diego County, USA. They love dry spots: scrubland, rocky arroyos, thorn forests and coastal flats. Like the US coachwhip, Masticophis fuliginosus is a fast-moving and twitchy snake which moves around by day. Their hunting strategy is to hide in mammal burrows, and poke just their head out, scanning their surroundings for prey. This snake eats mainly reptiles, including central Baja spiny lizards, desert iguanas, and orange-throated whiptails. Baja California coachwhips use mammal holes for shelter against the beating sun as well as hunting. Some snakes always swallow headfirst, but Masticophis fuliginosus can bite a lizard at the midsection and fold it into its mouth.
The Baja California coachwhip is shorter than the US version, averaging at 62-132cm. This snake has two colour phases: 1) yellow with dark zigzagging bands, and 2) dark brown all over, with light edges to scales.
| 2 | Baja California rattlesnake |
Baja California’s main venomous snake. Unlike the red diamond rattlesnake, this species doesn’t cross the border into US California, and is found only in Mexico.
Baja California rattlesnakes (Crotalus enyo) are a small species, reaching a maximum of 89.8cm. They sometimes slither into human areas, and take refuge below piles of trash, but this is mainly a snake of arid areas, interspersed with cacti and shrubs. They can be found on sand dunes, while in the east, they appear in pine-oak forests, but they never appear in dense jungles. Crotalus enyo have also been dragged out from under porches, and mammal burrows are their favourite natural refuge. This rattlesnake is crepuscular, coming out to play at dawn and dusk.
Crotalus enyo is far from the worst rattlesnake, as they have a small venom yield of just 31mg, compared to a western diamondback at over 175mg. Two studies have been conducted on their diet. One recorded 60.3% mammals, 33.3% reptiles, and 6.4% centipedes, while a 2016 study from the cape region was more tilted towards mammals at 83.3%, versus reptiles at 16.7%. Both studies found that spiny pocket mice were a popular prey.
| 3 | Coast patchnose snake |
This harmless snake lives in dry parts of northern Baja California: in coastal sage scrub and chaparral. They stay under cover, and will never slither directly up an open plain where birds can grab them. This snake is named for a strange “patch” shaped scale on the front of their snouts, which is theorised to be for digging up lizards and their eggs.
This snake is a subspecies of the main patch-nose snake, found in the southwestern US. The most common in California is the Mohave patchnose snake, but the coastal subspecies controls Baja California, as well as extreme southeast California, near San Diego. Coastal patchnose snakes (Salvadora hexalepis virgultea) are one of the most mysterious snakes in the Californian neighbourhood. This species has barely any research to its name at all. Few see them near San Diego, while in Baja California they’re a total enigma. In the few encounters, they were non-aggressive not only when cornered, but when picked up.
This snake looks vaguely similar to garter snakes, with a yellow vertical stripe down their spine, and dark black on either side. Patch-nose snakes reach a maximum of 117cm, typically 65-90cm.
| 4 | Baja California gopher snake |
This relative of the US gopher snake inhabits the whole of Baja California, except parts of the north. They’re also found on outlying islands, including Islas Magdalena, Santa Margarita and Isla San Jose. This snake can reach 168cm, beginning life at 30-48cm.
Cape gopher snakes are very common, yet no scientific surveys have ever been conducted. What we know is mainly anecdotal. In captivity, they gobble up pinkie mice, deer mice and lab rats with a vengeance, which is in line with the mammal-loving ways of US gopher snakes. They’ve been found in dry areas like scrubland and sandy desert. However, they also appear at the high altitude Sierra de la Laguna (2134 metres), an internationally protected zone heavy in pine and oak woodlands. They likely spend the day underground, escaping from the roasting Mexican heat, enjoying the cool darkness of their tunnels.
This snake has two subspecies, both contained entirely within Baja California. Pituophis vertebralis vertebralis is the cape gopher snake – found only on the southern tip of Baja California. This version has sharply contrasting orange and black patterns, with a red head from a bird’s eye view. P. v. bimaris is called the Baja California gopher snake, and is far more common, almost reaching the California border. This subspecies tends to be yellow-black instead.
| 5 | Sonora straminea |
This shy snake is found only in the southern tip of Baja California. Banded sand snakes (Sonora straminea) measure just 30cm and are no threat to human beings. They’re superb swimmers, but not in the way people are used to. Instead, they glide effortlessly through the upper layers of soft sands, a couple of centimetres down, just out of sight.
They’re specialised for this life in every way, with a shovel shaped head which is perfect for digging downwards. This is a brown and shiny snake, sometimes toffee-coloured, with black dots for eyes, and an expression as though it would never dream of hurting you. The reality is similar, as Sonora straminea is non-venomous and is too small to do damage with a bite. If picked up, they either do nothing or wrap themselves around your finger. One consistent feature is that their head is paler, sometimes lightening to grey. They have a pink tongue with a white tip.
Sonora straminea was only born as an official species in 2018, when it was broken off from the widespread variable sand snake. Their natural habitat is empty, wide open spaces covered with hot sand and cacti.
| 6 | Baja California ratsnake |
The Baja California ratsnake (Bogertophis rosaliae) is a unique species which is the only member of its family. It lives in the whole of Baja California from head to toe, and is a moderate sized snake at 85-152cm. Baja California ratsnakes are completely harmless to humans, with no venom or urge to mindlessly attack.
This snake lacks complex patterns, but has variable colours. They can be a colourful pink or they can have yellow-green tinges, while their eyes are some of the bluest of any snake. This is yet another lover of dry rocky habitats, which isn’t surprising given that Baja California is a dry rocky place. Canyons, bajadas, and thorn scrub are all potential hangouts of the Baja California ratsnake. They particularly like rocky arroyos close to small springs.
This snake is the subject of a mystery. Once upon a time, they were confined solely to Baja California on official maps. Then in Imperial County, a single Bogertophis rosaliae turned up 2.4km north of the US border. It was dead on a road, and confirmed rumours of more ratsnakes have appeared since then.
Thanks to the heat of Baja California, this snake can be active all year in the south, skipping hibernation. In the north, close to the US border, they’re active from February to October.
| 7 | West coast garter snake |
A garter snake found only in the south of Baja California. This species lives a stream life, similar to the aquatic garter snake of the US. The younglings stick to the shallow rocky edges, hunting for tadpoles, while they gain confidence to swim deeper. Adults can dwell in the faster flowing centres of streams, searching for amphibians and fish. West coast garter snakes know their way around their watery domains and when spooked, they instantly head for a large boulder to hide under. They can hold their breath for many minutes underwater, and have a mild venom which is harmless to humans.
West coast garter snakes reach a maximum of 110cm in females, while males are significantly smaller. This is one of the more elegant garter snakes. They have a jet black head, while their lower bodies are speckled with honey-coloured scales. Their bellies are slightly different, with sharp black and white bars. Their eyes are extremely black, and at first glance, they resemble a Nerodia watersnake more than a garter snake.
Thamnophis validus celaeno is actually a subspecies of the west coast garter snake; the other is T. v. validus, which lives on the Mexican mainland, and is greyer.
| 8 | Cape threadsnake |
A harmless snake which is incapable of killing a human. There’s only one place on Earth to find this snake – the southern tip of Baja California.
Cape thread snakes (Rena boettgeri) are a fossorial snake with mere black pen dots for eyes, adapted for their reduced light requirements. They only come out of their soil domains after heavy rains, and have an average length of 22.5cm. Their scales are extremely smooth, making them look like a worm, which is designed for gliding through soil smoothly. Their favourite habitat is dry coastal chaparral – in a rainforest, they wouldn’t know what to do.
The cape thread snake belongs to the Rena family (10 members), the same as the Texas blind snake. Whether cape thread snakes are completely blind is a mystery, but it’s assumed that they can sense whether it’s daylight or not, and little more than that. Cape thread snakes mainly prey on insects, and are more common near small streams within their dry chaparral, sometimes on the sandy banks.
| 9 | San Lucan rattlesnake |
A subspecies of the red diamond rattlesnake, which also lives in California. This version (Crotalus ruber lucasensis) lives only in Baja California and has its own grand title. They’re particularly concentrated in the far south and they’re most commonly witnessed by normal people on sandy dirt roads.
San Lucan rattlesnakes have the usual diamond patterns, but are slightly less red than the California version. This rattlesnake has brown-beige scales, a triangular head, and a black tongue which turns white again before reverting to black at the very tip.
This species doesn’t have the deadliest venom of any rattlesnake, but it varies significantly by region. A 2020 study found that in the Magdalena Plains region, the LD50 was just 6.8mg, while in the central gulf coast, it was a far nastier 1.4mg, stronger than a cottonmouth. Both regions are in southern Baja California. The toxins are mainly haemorrhagins, rather than the neurotoxins of a tiger rattlesnake.
| 10 | Mosauer’s ground snake |
A shy snake which isn’t seen often, but inhabits the majority of Baja California, from east to north. Mosauer’s ground snake (Sonora mosaueri) is harmless to humans and isn’t sighted often, though is occasionally found as roadkill after falling victim to car tyres.
Mosauer’s ground snake is a small species measuring 30-40cm, which varies wildly in appearance. They commonly have evenly spaced bands, which are especially neat and orderly, as you can see above. These vary in colour, as some are pink and pale black while others are dark black and white. Another chunk have no bands at all, and are a consistent fleshy pink.
This belongs to the same family as the western ground snake (Sonora semiannulata) of California. Mosauer’s ground snake has been on a rollercoaster ride. It was its own species for decades, until 1983, when it was declared as a subspecies of Sonora semiannulata. Then in 2018, mitochondrial DNA analysis confirmed it to be an independent species after all.
Officially, Mosauer’s ground snake doesn’t stray into US California, but it’s such a shy snake that anything is possible. This species may secretly have a tiny foothold in the far south.