Category: Reptiles

Southern Pacific Rattlesnake (Crotalus helleri)

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Crotalus helleri is a venomous pit viper species commonly known as the Southern Pacific rattlesnake. It is part of the family Viperidae, which includes venomous snakes known for their long, hinged fangs that allow them to deliver venom deep into their prey.

The Southern Pacific Rattlesnake (Crotalus helleri) hiding under a granite boulder in Bid Bear, California.
The Southern Pacific Rattlesnake (Crotalus helleri) hiding under a granite boulder in Bid Bear, California.

Description

Crotalus helleri typically ranges from 60 to 120 centimeters (2 to 4 feet) in length, although some individuals can grow larger. The snake exhibits a variety of color patterns depending on its geographical location. Common colors include brown, olive, gray, and occasionally greenish tones. The body is marked with dark, diamond-shaped blotches running along the length of its back, often bordered by lighter scales. These blotches may be less defined in older individuals. The snake’s head is triangular with a distinct neck, and it has a characteristic rattle at the end of its tail, which it uses as a warning signal.

Distribution and Habitat

Crotalus helleri is primarily found in Southern California, extending into Baja California, Mexico. Its range includes a variety of habitats such as coastal sage scrub, chaparral, grasslands, woodlands, and deserts. The snake is adaptable and can be found at elevations from sea level to over 2,000 meters (6,600 feet).

Behavior

This species is generally diurnal in the cooler months and becomes more nocturnal during the warmer summer months to avoid the heat. Crotalus helleri is a sit-and-wait predator, typically ambushing its prey, which includes small mammals, birds, lizards, and amphibians. The snake’s heat-sensing pit organs, located between the eyes and nostrils, allow it to detect warm-blooded prey even in total darkness.

Reproduction

Crotalus helleri is ovoviviparous, meaning that the females give birth to live young rather than laying eggs. Mating occurs in the spring, and after a gestation period of about 5 to 6 months, the female gives birth to a litter of 4 to 12 young, usually in late summer or early fall. The newborn snakes are independent from birth and are capable of hunting and defending themselves immediately.

Venom

The venom of Crotalus helleri is highly toxic and is composed of a mixture of hemotoxins, neurotoxins, and myotoxins. This potent combination can cause significant tissue damage, disrupt blood clotting, and lead to paralysis. Envenomation in humans requires immediate medical attention, as the venom can be life-threatening if untreated. Antivenom is effective, but the severity of the bite varies depending on the amount of venom injected.

Conservation Status

As of now, Crotalus helleri is not listed as endangered or threatened. However, like many species, it faces threats from habitat destruction, human encroachment, and intentional killing due to its venomous nature. Conservation efforts focus on habitat preservation and public education to reduce unnecessary killings.

Ecological Role

Crotalus helleri plays a crucial role in its ecosystem as both predator and prey. As a predator, it helps control the populations of small mammals and other prey species, which in turn influences the population dynamics of these animals. As prey, it provides food for larger predators such as hawks, eagles, and some mammalian carnivores.

Human Interaction

Encounters between humans and Crotalus helleri are relatively common in Southern California, especially in areas where urban development encroaches on natural habitats. While the snake is generally not aggressive and prefers to avoid confrontation, it will defend itself if threatened. Public education on rattlesnake behavior and safety is essential to minimize negative interactions and ensure the safety of both humans and snakes.

Taxonomy and Classification

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Reptilia
  • Order: Squamata
  • Family: Viperidae
  • Genus: Crotalus
  • Species: Crotalus helleri

Conclusion

Crotalus helleri is a fascinating and important species within its range. Understanding its biology, behavior, and ecological role is essential for promoting coexistence between humans and wildlife in regions where this rattlesnake is found. Conservation efforts should focus on habitat protection and educating the public about the importance of this species in maintaining ecological balance.

Desert Tortoise (Gopherus agassizii)

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One of  the more unique and quite frankly cool animals found in the Mojave Desert is the Desert Tortoise ( Gopherus agassizii ).  My family has a connection with this nomad of the dessert in that during the spring of 1942, my grand parents inherited three desert tortoises when they purchased and moved into a house in Ontario, CA.

Hands Off
Hands Off

My grandmother quickly named and adopted her new pets.  She and my grandfather struck up a deal with a local grocery store to donate lettuce and other vegetables to my grandmother to care for the tortoises.  By the time I was born, the three tortoises became a populations of about 20 animals.  Some of my earliest memories was to help her wake up the “turtles” from their hibernation, during which she stored the animals in a  large box along with a bunch of news paper clippings to help insulate them a little bit from the California winters.

Over the years, those three tortoises expanded their family and ours into a breeding population of over 70 animals.   Eventually, we donated the captive born tortoises to several zoo’s, shelters, and rescue to care for the animals.  All in all, my family raised and cared for desert tortoises for about 60 years, the ownership of which was legal because family documentation and the fact that all of the animals were born in captivity.

California Desert Tortoise emerging from a hiding place...
California Desert Tortoise emerging from a hiding place…

Oddly enough, despite my best efforts I did not a desert tortoise in the wild until the late 1990s when I ran into the one emerging from a den during one of the Toyota Four Runner Jamborees which was located out of Stoddard Wells Road.  Surrounded by others, most of whom I did not know, I quietly photograph the tortoise and pointed him out to my brother and two friends.  I chose not to point him out for fear of someone in the group would take it after we left.

Desert Tortoise (Gopherus agassizii) in its burrow
Desert Tortoise (Gopherus agassizii) in its burrow

Since this initial sighting, I have found four more in the wild.  One sighting occurred while driving the old Mojave Road with my father.  The animal was just walking down the trail.  We stopped and waited about 45 minutes for the animal to clear the road.  The other animal were spotted while driving at speed along various highways in the Mojave.  One animal I found walking down the middle of the road and had I not stopped and moved the animal off the road, it surely would not have survived long.

A juvenile desert tortoise lost its battle for life in the harsh desert environment. Photo by James L Rathbun
A juvenile desert tortoise lost its battle for life in the harsh desert environment. Photo by James L Rathbun

When born, the tortoises shell is thin and fragile which makes it an easy food source for Ravens, Gila monsters, kit foxes, roadrunners, coyotes, and fire ants.  Only about 2% are expected to reach maturity and the population in the Mojave is listed as threatened.  Should you be lucky enough to see one in the wild, take your time. Enjoy the moment. Snap a photograph and then leave the tortoise along.  I can tell you the exact spot of each of the five sightings I have had the good fortune to have experienced.  Each sighting of this timeless desert nomad is unique, and should be protected.

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Western Fence Lizard (Sceloporus occidentalis )

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The Western Fence Lizard ( Sceloporus occidentalis ) is perhaps one of the most common lizards in the desert southwest and is also known as a “Blue belly”. Perhaps this commonality is the reason for its name. The Western Fence lizard is found in a variety of habitats and common at elevations up to 10,800 feet. They can be located in forests, desert sage, farmlands and grasslands. This species is typically not found in harsh desert climates and moist forests.

Western Fence Lizard
Western Fence Lizard

This animal is typically between 2 inches and 3.5 inches in length. They are typically black to brown in colors with stripes on their backs. They have blue colored patches on their ventral abdomen. This reptiles will lay clutches of eggs between 3 and 17 eggs in the spring between April and July. The eggs will hatch within two months of feralization.

This animal are known to eat insects including ant, beetles, flies, spiders and some caterpillars. They typically can be found sunning themselves on rocks, fences and paths. The are a prey item for other animals including larger lizards, birds and also some a mammals. As is common with most reptiles, the lizard is known to hibernate in cooler winter months.

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Zebra Tailed Lizard ( Callisaurus draconoides )

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The Zebra-Tailed Lizard is a medium sized lizard which features a long black and white striped tail and commonly found in California, Arizona and Nevada. Additional coloring includes two rows of brown / bray spots down the middle of the back, and is often marked with cream colored spots. The males boast belly bars which range in color from blue to yellow and orange. The females belly bars are often much more muted or lacking completely.

A male Zebra-Tailed Lizard ( Callisaurus draconoides )
A male Zebra-Tailed Lizard ( Callisaurus draconoides )

This animal is commonly between 4 and 6 inches in length from snout to vent and its regenerative tail may double to overall length of this animal. The female lays a clutch of up to 15 eggs, however the more common number is between 2 and 8 eggs. A healthy population will host between 4 and 6 lizards per acre, however the number seems much higher when they are darting around you in the Mojave, Great Basin or Sonaran deserts

The Zebra tails are frequently found at elevations up to 5,000 feet. The are usually found in areas which have sandy soils and open spaces in which they can run. An ambush predator, the lizard will often lie in way for its dinner to walk by and is known to feed on bees, wasps, beetles, caterpillars, ants and grasshoppers. Additionally it is known to consume other small lizards and spiders.

Very tolerant of the high heat of the desert in which it lives, the feisty lizard is known to be active during the high temperatures of the summer sun when most animals seek shade and go underground. These lizards are know to alternately stand on opposing feet and alternate between then two stances as a means of protection from the harsh landscapes in which it lives. During the cooler nights, the lizard may burrow down into fine sane, however is also known to sleep on the surface on warm nights.

When spotted by a predator, the reptile will curl its boldly stripped tail over its head which may serve notice to the predator that it was spotted. When needed a quick burst of speed will serve as the best prevention to being a meal to larger animals.

A Zebra Tailed lizard photographed ny my lovely wife in the Ivanpah Mountains of California.
A Zebra Tailed lizard photographed ny my lovely wife in the Ivanpah Mountains of California.

Desert Horned Lizard (Phrynosoma platyrhinos)

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Desert Horned Lizard (Phrynosoma platyrhinos)
Desert Horned Lizard (Phrynosoma platyrhinos)

Desert Horned Lizard (Phrynosoma platyrhinos), also known as the “horny toad”, is a common North American reptile and found throughout the southwest and the Mojave. A personal childhood favorite of mine, the horned lizard does have the appearance of a small dinosaur and it a master of camouflage.

This is a small to medium sized lizard, its 3 – 5 inch broad and flat body features a prominent series of fringed scales. Its head also boasts several horn which offers the lizard its name. Undoubtedly, the overall body shape is that of a toad is also a contributing factor. The coloration of the body will vary to help the lizard blend into its background.

The reptile’s diet is small insects and is commonly found at or near ant mounds where they will lie in wait for its meal to simply walk by. Generally speaking this animal is found at elevations below 6500 feet in creosote-bursage flats and Mojave Desert Scrub.

Desert Horned Lizard, a master of camouflage
Desert Horned Lizard, a master of camouflage

Defensively, the little lizard is all about appearances. Primarily, camoflauge allows it to remain hidden in plain sight. The reptile is known to hiss and puff up its chest when confronted in an effort to appear larger and more dangerous that it really is known to be. Some species of the genus are known to squirt blood from its eyes and may reach a distance of 5 feet.