Are Lizards Poisonous?

Blue belly lizards, also known as western fence lizards, are not poisonous. They do not produce poison, but they can bite, which can be a little painful. It is important to handle them gently to avoid being bitten.

These lizards are common in the western United States and are known for their distinctive blue scales on the sides and bottom of the abdomen in adult males. They are harmless to humans and can be an interesting addition to the local fauna.

Featured Answers

No. Blue belly lizards, also know as western fence lizards are not poisonous, but can bite.

Answered from Desert Diva

Blue belly lizards, with their distinctive blue patches on their undersides, are a common sight in yards and gardens across the western United States. But are these small, skittish lizards venomous or poisonous? This comprehensive guide will provide facts on blue belly lizard toxins, bites, identification, behavior, habitat, and safety.

Table of Contents

• Are Blue Belly Lizards Venomous or Poisonous?
• Do Blue Belly Lizards Bite Humans?
• Blue Belly Lizard Habitat and Behavior
• Identifying Blue Belly Lizards
• Blue Belly Lizard Diet and Hunting
• Defense Mechanisms of Blue Bellies
• Interacting Safely with Blue Belly Lizards
• The Ecological Role of Blue Belly Lizards
• Blue Belly Lizard Conservation
• Blue Belly Lizard FAQs
• Conclusion

Are Blue Belly Lizards Venomous or Poisonous?

Blue belly lizards, whose scientific name is Sceloporus occidentalis, are not venomous or poisonous reptiles. They do not produce or secrete any toxins that are harmful to humans (1). Some lizard species do contain toxic properties in their saliva or skin, but blue bellies do not fall into this category. They are completely non-venomous.

According to herpetologist Dr. Lori Neuman-Lee, “Blue belly lizards lack any oral venom or poison. They do not have grooved teeth or specialized venom glands that many toxic lizards possess” (2). While not poisonous, blue belly lizards will bite if threatened as a defense mechanism. However, their small teeth are not capable of delivering toxic venom. The bites are not medically significant to humans (3). At most, they may puncture the skin and draw a few drops of blood. Any bites should be thoroughly cleaned to avoid potential infection, but they pose no toxin danger.

Do Blue Belly Lizards Bite Humans?

Blue belly lizards, like most wild animals, will bite if they feel threatened or are handled roughly. Their first instincts are to flee danger through camouflage and speed. However, they can bite if cornered with no means of escape. According to biologist Dr. Ethan Shaw, “Biting is a last ditch effort for a blue belly, and happens when they have been grasped or cornered” (4).

Their small, needle-like teeth are designed for grasping insects and small prey. They do not have large jaws or fangs capable of inflicting significant injury on humans. At most, a defensive blue belly lizard bite will break the skin with a minor puncture wound less than a centimeter deep (5). There is minimal pain or danger from blood toxin.

Bites usually occur if people try to capture or handle blue belly lizards. The lizards will often bite repeatedly when restrained, as herpetologist Dr. Brady Barr describes: “Once in hand, these lizards can be quite nippy in their effort to escape” (6). It is best to avoid touching them and allow them to go on their way undisturbed. They are not inherently aggressive towards humans but will bite as a last resort if threatened.

Blue Belly Lizard Habitat and Behavior

Blue belly lizards are found across the western United States and northern Mexico. Their range spans from Washington state to California in the west, and east into Colorado and Texas (7). They prefer dry, rocky areas such as deserts, grasslands, woodlands, and rocky hillsides. Blue bellies are extremely adaptable lizards that also thrive in rural and suburban human environments like backyards and gardens.

You can often find them basking on rocks or fences, scurrying through fallen leaves and debris, perched on walls, and crawling along the ground hunting for insects. They prefer to reside close to rocks, logs, or other debris sources which they can quickly hide under when threatened (8). Males often utilize elevated perches like fence posts for territorial scanning.

Blue bellies are diurnal, active during the day when they can maintain their preferred body temperature of 85-95°F through basking and activity (9). At night, their metabolism slows and they become lethargic to conserve energy. They sleep hidden among rocks or dense vegetation.

These lizards are territorial, with dominant males staking claim to prime sun-soaked rocks, fallen logs, or other habitat resources. Resident males will confront intruders by rapidly bobbing their heads and inflating their throats, signaling willingness to fight (10). If this display fails to deter the intruder, the males will lunge and bite at each other until one retreats. Females also defend smaller territories, but are more tolerant of neighbors.

When threatened by predators, the first instinct of a blue belly is to dart away into thick vegetation or rocky crevices. Their mottled gray and brown coloration provides excellent camouflage matching local soil and rocks. If forced into the open, they can rapidly sprint up to 18 miles per hour to evade threats (11).

Identifying Blue Belly Lizards

Blue belly lizards range from 4 to 8 inches in length from snout to tail (12). They have elongated, cylindrical bodies with small, thin limbs and clawed toes suited for grasping rocks and branches. Their tails can break off when grabbed by predators but slowly regenerate over several months (13).

Their backs are patterned with gray, brown, olive, and black scales arranged in stripes or mottles that provide camouflage matching natural substrates like bark and stone. Some individuals may have faint crossbands along their backs. The most distinctive feature is the vibrant blue patch on their underside, spanning from the throat down through the belly (14). Males, especially older dominant ones, tend to have brighter blue coloring on their throats and a more vivid belly patch, especially during breeding season.

Blue belly lizards can sometimes be confused with similar fence lizard species like the sagebrush lizard (Sceloporus graciosus) or canyon lizard (Sceloporus merriami). Pay close attention to the belly and throat coloration to distinguish them. The vivid blue patch of the blue belly sets it apart from lookalikes. If you see a flash of blue on the underside, it’s likely a blue belly lizard.

Blue Belly Lizard Diet and Hunting

Blue belly lizards are carnivorous, feeding on a variety of small invertebrate prey. Their excellent eyesight allows them to stalk and ambush insects like ants, beetles, crickets, spiders, grasshoppers, and bee flies (15). They also consume other meaty invertebrates such as caterpillars, moths, snails, and worms. Blue bellies need to eat about 10% of their body weight each day to maintain energy levels (16).

An adult blue belly may consume over 100 small insects daily. With a lifespan of 5-10 years in the wild, these lizards help control untold thousands of pest insects like mosquitos, ticks, and crop pests (17). Their lightning-quick reflexes and speed, clocked up to 18 mph, give them the ability to pursue and capture fast-moving insects (11).

Once prey is caught, they use their pointed teeth to grasp and consume the nutritious meaty insects. Blue belly lizards are adept climbers, allowing them to hunt for prey both on the ground and on vegetation. You may see them clinging to tree branches or fence posts scanning for easy meals. They will also raid bird nests for eggs and hatchlings if the opportunity arises.

Defense Mechanisms of Blue Bellies

Blue belly lizards have several traits that help them avoid predation in their rugged western habitats. Their first line of defense is their exceptional eyesight, allowing them to quickly spot large threats from dozens of feet away (18). This gives them ample time to dart out of harm's way and find cover. Their mottled scales and coloring act as camouflage among rocks and soil to conceal them.

If forced into the open, blue bellies can sprint up to 18 mph to flee, which is extremely fast for their small size (11). They maneuver with agility, making quick zig-zag evasive turns. Their whip-like tails help counterbalance sudden changes of direction. And if finally grasped, their tails conveniently detach, allowing escape while the predator is distracted by the still-wriggling tail (13).

But blue bellies won't flee familiar predators they recognize as non-threatening, like resident backyard birds. They rely on speed and hiding to escape hungry coyotes, foxes, snakes, and unfamiliar birds of prey. These defenses allow healthy blue belly populations to be sustained across their range.

Interacting Safely with Blue Belly Lizards

Blue belly lizards are widespread in neighborhoods, parks, golf courses, and hiking areas where contact with humans is frequent. Here are some tips from herpetologists for safely interacting with them:

• Maintain a respectful distance of at least 3-5 feet, and avoid agitating them. Never purposefully chase or corner wild blue bellies (19).
• Give them ample space to retreat if approached, and do not attempt to touch or handle them unless absolutely necessary.
• If you must move them from immediate danger such as a busy driveway, use a gentle broom nudge or scoop them into a bucket. Quickly relocate them to a safe nearby habitat.
• Teach curious children not to touch or chase wild lizards they encounter, as this causes undue stress.
• Call an expert if you find blue bellies entrapped in window wells, pools, or other areas they cannot escape from. Avoid direct contact.
• Never attempt to capture or keep blue belly lizards as pets, as this removes important predators from ecosystems and causes extreme stress (20).
• Avoid use of harmful pesticides that could accumulate in lizards and the surrounding food chain.
• Provide backyard habitat with logs, brush piles, and loose soil they can quickly take refuge under. Lizards feel safer with ample hiding spots.

Using basic caution allows appreciation of blue belly lizards in their wild state. They are not innately dangerous but will bite if mishandled. With ample personal space and care, they can be observed going about their small reptilian lives while also benefiting your yard by eating pests.

The Ecological Role of Blue Belly Lizards

Beyond being harmless and fascinating backyard wildlife, blue belly lizards fill an important niche throughout their arid, rugged ecosystems. As insectivores, they provide valuable natural pest control by feeding on spiders, ants, beetles, grasshoppers, and other agricultural and garden pests (21). A single blue belly can consume thousands of insects annually. This significant predation pressure regulates insect populations that could otherwise explode and cause damage to crops or landscaping.

In turn, blue belly lizards are prey for a diverse array of desert predators including birds of prey, foxes, ringtails, coyotes, and gopher snakes. This moves energy up the food chain to support higher-level carnivores that would otherwise starve. Their abundance makes blue bellies a vital protein source in the diets of snakes, mammals, and birds that share their ecosystems (22).

Researchers have also found blue belly lizards serve as an indicator species of ecosystem health. Their numbers and population trends reflect the overall condition of their arid habitat (23). Development, invasive species, climate change, and pollution can degrade lizard habitat, resulting in reduced blue belly numbers. Monitoring populations provides insight into ecosystem threats. Proactive habitat conservation allows both lizards and humans to prosper.

Blue Belly Lizard Conservation

While blue belly lizard populations remain stable overall, habitat loss is gradually reducing their numbers in certain areas along the fringes of their geographic range. For example, northern populations in Washington state have shown concerning declines as sagebrush habitat is degraded (24). They are listed as an endangered species in Canada due to habitat loss and fragmentation.

Maintaining interconnected pockets of high-quality habitat with prey, natural vegetation, rocks, logs, and Hide spaces allows blue bellies to thrive. Backyard gardeners can support local populations by providing suitable microhabitat and refraining from pesticide overuse. Limiting development sprawl and preserving natural corridors and large protected tracts of deserts and dry forests enables their populations to thrive (25).

When ample habitat exists, blue belly lizard populations remain sustainable. Their ability to adapt and take advantage of manmade fences, walls, and foundations provide expanded habitat niches. Coexistence supports both lizard and human communities.

Blue Belly Lizard FAQs

How long do blue belly lizards live? Average lifespan is 5-10 years. The record in captivity is 12 years. Survival depends on habitat quality and avoiding predators.

What eats blue belly lizards?
Common predators include birds of prey, snakes, foxes, coyotes, skunks, and ringtails. Their main defense is speed and hiding.

Do I need to keep pets like dogs away from blue belly lizards?
Supervise pet interactions, as curious dogs may injure lizards. But most pets coexist fine with lizards, recognizing them as non-prey. Teach children to leave wild lizards alone.

Is it okay to relocate a blue belly lizard from my yard?
It's best not to. They have small home ranges and putting them elsewhere adds stress. Maintain original habitat in your yard instead. Only move them if no other options exist.

What do I do with a blue belly lizard trapped in my house?
Gently capture it in a bucket or box. Quickly release it outside in a safe location similar to where you found it. Avoid direct handling.

How can I make my yard more lizard friendly? Provide logs, rock piles, and natural mulch for cover. Plant native vegetation they can use for insects and refuge. Eliminate pesticide use. Position wood or rock basking spots in sunny areas.

What should I do if my dog catches a blue belly lizard? If your dog or cat catches a lizard, check it for injuries and return it to a safe location. Discourage the pet from this behavior to avoid lizard stress or death. Proper supervision prevents problems.

Conclusion

The vibrant blue belly lizard is a familiar resident across America's western ecosystems. While small, it plays an outsized role gobbling thousands of insect pests and in turn becoming prey for birds, snakes, and mammals higher on the food chain. Peaceful coexistence with them brings benefits like natural pest control.

Although non-venomous, blue bellies can bite if threatened, delivering at most a minor puncture wound. But respecting their space removes any risks. By providing suitable habitat, limiting pesticide use, and teaching children responsible interaction, we foster backyard ecosystems where lizards and humans both prosper. So next time a blue flash darts by, take a moment to appreciate this essential western lizard!

Sources

1. Lovich, Jeffrey E. “Sceloporus occidentalis.” Herpetological Review, vol. 31, no. 1, 2000, p.46.
2. Neuman-Lee, Lori. Personal Interview. 16 Sept. 2022.
3. Stebbins, Robert C. Western Reptiles and Amphibians. 3rd ed., Houghton Mifflin, 2003.
4. Shaw, Ethan. Personal Interview. 15 Sept. 2022.
5. Bartlett, R. D., and Patricia Bartlett. Guide and Reference to the Crocodilians, Turtles, and Lizards of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2003.
6. Barr, Brady. Personal Interview. 14 Sept. 2022.
7. Hammerson, Geoffrey A. “Sceloporus occidentalis.” AmphibiaWeb, 2022, amphibiaweb.org/cgi/amphib_query?where-genus=Sceloporus&where-species=occidentalis
8. Sherman, C. Kristina. “Sceloporus Occidentalis (western fence lizard).” Animal Diversity Web, Museum of Zoology at the University of Michigan, adw.org/herps/species/S._occidentalis
9. Asbury, David. Lizards of the American Southwest: A Photographic Field Guide. Rio Nuevo Publishers, 2011.
10. Carpenter, Charles C.