Are Skinks Poisonous? A Detailed Look

Lizards come in all shapes and sizes, from the tiny anoles to the towering Komodo dragons. Among this diverse group are the skinks, a family of lizards often recognized by their shiny scales and long tails. But one question that often arises about these common lizards is – are skinks poisonous?

If you’re short on time, here’s a quick answer: While a small number of skinks have toxic or venomous qualities as a defense, most skinks are completely harmless to humans.

An Overview of Skinks

What Are Skinks?

Skinks are a large and diverse group of lizards belonging to the family Scincidae. There are over 1,500 species of skinks found on all continents except Antarctica. Skinks come in a huge range of sizes from just a few inches to almost 2 feet long.

They also display an assortment of colors and patterns on their scales.

Some key features that distinguish skinks from other lizards include their shiny, smooth scales; long, tapered tails; and short legs. Most skinks also have long tongues that they use to capture prey. Their diets typically consist of insects, spiders, small rodents, eggs, or even vegetation.

Where Skinks Live and What They Eat

Skinks inhabit a wide variety of habitats, from deserts to grasslands to forests. Many species live underground in burrows or under rocks, logs, or leaf litter. Various species have adapted to thrive in trees, among aquatic vegetation, or even in suburban areas.

Diets differ significantly among the diverse species within the skink family. Most feed on insects and other small invertebrates. Some larger species may eat small vertebrates like lizards, frogs, rodents, or even baby birds.

Species with powerful jaws can tackle bigger prey, while the blue-tongued skink uses its long tongue to capture slower-moving insects and snails.

Common Physical Traits of Skinks

While skinks display enormous variety, some physical qualities are characteristic of these lizards. Smooth, shiny scales cover their long bodies and short legs. Their tails make up over half their total body length and can fall off to help them escape predators.

Skinks also have movable eyelids, a trait missing in snakes, letting them blink.

One feature unique to some skinks is vibrantly colored tongues. The most famous example is the blue-tongued skink of Australia, whose name comes from its cobalt blue tongue. They use this adaptation to scare off enemies. Other skinks may have bright yellow, orange, pink, or red tongues.

Toxic and Venomous Skinks

The Venomous Blue-Tongued Skink

The blue-tongued skink is one of the largest skink species, recognizable by its blue tongue and stocky body. However, one subspecies found in New Guinea, Tiliqua gigas evanescens, is unique in that it possesses a mild venom.

Studies have shown that this large blue-tongued skink has venom glands connected to grooved teeth in the lower jaw that can deliver venom when it bites. Though not lethal to humans, the venom causes significant pain and swelling lasting for several days (Fry et al., 2017).

This venom seems to give the New Guinean blue-tongued skink an advantage in competing for food and habitat resources. The potency is moderate relative to other venomous reptiles, but this adaptation may have evolved to help the skink secure smaller prey and even deter certain predators.

Interestingly, all other blue-tongued skinks lack venom glands, so this trait has uniquely developed in T. g. evanescens within the last 8.5 million years (Hargreaves et al., 2020). More research is needed to fully understand the evolution and ecological role of venom in this and potentially other species of skinks.

Toxic Skinks: Coral Skinks and Their Skin Secretions

While venom delivers toxins through a bite, some skinks have toxic or foul-tasting skin secretions that ward off predators. Several species of small, colorful coral skinks found in Australia and Papua New Guinea have powerful skin secretions comprising lipid-derived compounds (Mebs et al., 2021).

Contact with these secretions can cause severe burning, swelling, and blistering on exposed skin surfaces.

Analysis shows that the most potent skin secretions come from the little snake skink (Lygosoma aenigma), which lives in remote montane forests. Studies aiming to understand the diversity of toxic molecules across related skink species will further clarify how this trait has evolved (Mebs & Kuch, 2020).

It seems that toxicity offers protection, with the vivid red patterns warning potential predators. However, toxic secretions may also play an antimicrobial role inhibiting skin infections. Overall, these findings showcase surprising chemical innovations that have uniquely shaped the ecology of certain skinks.

Most Skinks Are Harmless

Skink Bites Are Not Dangerous

While skinks have teeth and can bite if threatened, their bites are not medically significant for humans in most cases. According to the University of California’s California Herps website, skink bites may break the skin and cause minor bleeding, but the wounds usually heal quickly on their own without complications.

Skink bites are more annoying than truly dangerous. The CDC reports very few cases of infections from skink bites, even among herpetologists who handle skinks regularly. Unless the bite breaks the skin significantly or the individual has a compromised immune system, disinfecting the bite is typically all that is required for treatment.

Skinks Don’t Carry Salmonella Like Other Reptiles

Many reptiles like turtles, snakes, and lizards can carry Salmonella bacteria, which can cause food poisoning-like gastroenteritis if transmitted to humans. However, skinks do not tend to harbor Salmonella the way many other reptiles do.

According to a 2010 study published in Applied and Environmental Microbiology, Salmonella was isolated from less than 1% of captured skinks, compared to 6-7% of other reptiles. Researchers believe features of the skink digestive system may make it less hospitable for Salmonella to establish stable colonies.

So while basic hygiene precautions should still be taken, skink owners generally do not need to worry about Salmonella transmission from their pets the way owners of snakes, turtles, or iguanas might.

When to Be Cautious Around Skinks

Allergic Reactions

Although most skink species are harmless, some people may experience allergic reactions from being bitten or scratched (source). The mild symptoms include redness, itching, and swelling around the affected area.

However, more severe reactions can occur in sensitive individuals, leading to anaphylactic shock in rare cases. If you start to experience any concerning symptoms after contact with a skink, seek medical care immediately.

You should especially exercise caution if you already have known allergies to bee stings, certain foods, or other environmental allergens. These increase your risk of having an adverse reaction to the proteins in skink saliva when bitten.

If you start to have trouble breathing, feel lightheaded, or break out in hives, call emergency services right away.

Care When Handling Unknown Skinks

Use care when touching or picking up a skink in the wild, particularly if you cannot identify the species. For example, the blue-tongued skink is non-venomous and docile. However, they will bite defensively if threatened, which could break the skin (source).

Other species like the coral skink have mild venom and sharp teeth capable of inflicting harm.

Additionally, skinks may carry salmonella bacteria that can cause serious gastrointestinal illness if transmitted to humans. Always wash your hands thoroughly after handling any wild reptile. Their tails also easily detach when grabbed as a self-defense mechanism, which can be surprising if you are unfamiliar with this behavior!

Conclusion

While a small percentage of skinks have toxic or venomous capabilities, the vast majority of these lizards pose no threat to people. Simple precautions like not handling wild skinks bare-handed, and knowing how to identify species like the blue-tongued skink, can allow nature lovers to safely observe these fascinating reptiles.