“Blue-tailed skink” is a nickname, not a species. It usually refers to the young of a small, smooth-scaled lizard that is common in yards and woodlands, in North America mostly the common five-lined skink and its close relatives.1Missouri Department of Conservation. Common Five-Lined Skink The bright tail belongs to the young and doesn’t last into adulthood. It is a deliberate target, meant to draw a predator’s bite away from the head and body.2Canadian Journal of Zoology. Tail loss, tail color, and predator escape in <i>Eumeces</i> (Lacertilia: Scincidae): age-specific differences in costs and benefits The lizards are harmless to people.
Which Lizards Get Called Blue-Tailed Skinks
Hatchlings and young adults of the common five-lined skink are black with 5 yellow stripes running from the head to the base of the tail. They also have a bright blue tail, which is where the nickname comes from.3Missouri Department of Conservation. Common Five-Lined Skink The young of some other skinks also have black bodies with blue tails, so the look alone does not settle the species.4Missouri Department of Conservation. Common Five-Lined Skink In the Southeast, the broad-headed skink and the southeastern five-lined skink are the usual look-alikes, and both also carry blue tails when young.5Zeitschrift für Tierpsychologie. Blue Tails and Autotomy: Enhancement of Predation Avoidance in Juvenile Skinks6Amphibia-Reptilia. Secondary sexual coloration is related to white blood cell counts and testosterone in male southeastern five-lined skinks (Plestiodon inexpectatus)
A skink’s glossy shine sometimes leads people to mistake it for a salamander, or to think the skin is slimy. It isn’t. Skinks have dry scales and claws, while salamanders have moist skin and no claws. Skinks also bask in the sun, and salamanders hide in damp places.
Fence lizards are the other common mix-up in eastern yards. They are gray-brown, rough, keeled, and spiky-looking, while a young five-lined skink is smooth and glossy with a dark body. Fence lizards often perch in the open on posts and tree trunks, while skinks stay low and slip into cracks when approached.
In pet stores, “blue-tailed skink” usually means the Pacific blue-tailed skink, a tropical island lizard and a different animal from the backyard species.7Dubia.com. Pacific Blue-Tailed Skink Care Sheet In Florida, the rare blue-tailed mole skink is a separate, threatened sand-dwelling species.8U.S. Fish and Wildlife Service. Sand Skink and Blue-tailed (Bluetail) Mole Skink Species Conservation and Consultation Guide In the eastern or central US, the lizard you saw is very likely a young native skink; the Pacific species is not wild there.
Why the Tail Is Blue
The color seems to shift a predator’s attention from the body to the tail, a decoy the lizard can sacrifice as a last defense.9Canadian Journal of Zoology. Tail loss, tail color, and predator escape in <i>Eumeces</i> (Lacertilia: Scincidae): age-specific differences in costs and benefits10Zeitschrift für Tierpsychologie. Blue Tails and Autotomy: Enhancement of Predation Avoidance in Juvenile Skinks Against kingsnakes, an intact tail deflected attacks away from the body about half the time.11Zeitschrift für Tierpsychologie. Blue Tails and Autotomy: Enhancement of Predation Avoidance in Juvenile Skinks
You may see this in action. Young skinks often wiggle or wave the tail when approached, which pulls a strike toward the tail rather than the head. A skink that freezes with a twitching tail is using this defense, not acting sick.
The trade carries a risk. Lizard models with blue tails were attacked more than twice as often as all-brown ones, 28% versus 11%.12Current Zoology. Bite me: Blue tails as a ‘risky-decoy’ defense tactic for lizards But attacks on the blue-tailed models landed mostly on the tail, while brown models were hit on the head or body.13Current Zoology. Bite me: Blue tails as a ‘risky-decoy’ defense tactic for lizards
That is worth it because a predator that bites a tail usually ends up with a wriggling piece while the lizard escapes. Young skinks are small and have many predators, including snakes, birds, and small mammals, so a strong decoy matters most when they are most vulnerable.
The blue is tuned to predators that can see it, such as snakes and weasels.14Journal of Zoology. Cellular basis of anti‐predator adaptation in a lizard with autotomizable blue tail against specific predators with different colour vision Where snakes are the main predators, tails also reflect ultraviolet light that snakes see but people cannot.15Journal of Zoology. Cellular basis of anti‐predator adaptation in a lizard with autotomizable blue tail against specific predators with different colour vision
In many animals, bright colors warn of poison, but here they invite a bite. The tail is not toxic to people, cats, or dogs, and the story that blue tails poison cats is a folk tale with no support.
How and Why Skinks Drop Their Tails
Most lizards shed the tail at the point where a predator grabs it.16PubMed. Energetic costs of tail loss in a montane scincid lizard The tail has built-in break points where the muscle segments are held together loosely enough to separate cleanly.17PubMed Central. Unique Structural Features Facilitate Lizard Tail Autotomy The lizard controls the break itself, using muscle contractions, so it can drop the tail even without being touched.18PubMed Central. Ontogeny and caudal autotomy fracture planes in a large scincid lizard, Egernia kingii
There is very little blood because muscles near the break squeeze the blood vessels, which limits bleeding and lets the skink run off with a short stump. The dropped tail keeps wriggling for a while, which holds the attacker’s attention.
Skinks store fat in the tail, mostly in the part nearest the body.19PubMed. Energetic costs of tail loss in a montane scincid lizard Losing only the tip costs little energy, but losing most of the tail costs a lot.20PubMed. Energetic costs of tail loss in a montane scincid lizard In one skink, running speed did not suffer until more than half the tail was lost.21PubMed. Energetic and locomotor costs of tail loss in the Chinese skink, Eumeces chinensis Newborn skinks that lost the whole tail ran about 50% slower, a larger drop than the 35% seen in adults.22Journal of Herpetology. Effect of Tail Loss on Sprint Speed and Growth in Newborn Skinks, Niveoscincus metallicus Still, young skinks kept growing and regrew at least a third of the tail within eight weeks.23Journal of Herpetology. Effect of Tail Loss on Sprint Speed and Growth in Newborn Skinks, Niveoscincus metallicus
The new tail grows from the stump, and it is usually supported by a rod of cartilage rather than the original bony segments. It tends to be shorter, duller, and often a different color. Because it isn’t built with the same break points, a second drop typically occurs higher up, closer to the body, which costs more stored fat.
That’s why it’s best never to pick up a skink by the tail. If you must move one, herd it gently into a container. A skink without its tail is more vulnerable for weeks afterward, so leave it in cover.
Why the Blue Fades With Age
The tail is brightest just after hatching.24PubMed Central. Ontogenetic color change in the tail of blue‐tailed skinks (Plestodion elegans) In older juveniles it darkens to a deeper blue, and in mature adults it fades to brown or a dull yellowish color in both males and females.25PubMed Central. Ontogenetic color change in the tail of blue‐tailed skinks (Plestodion elegans) Adult tails are camouflaged, since adults rely less on the decoy.26Canadian Journal of Zoology. Tail loss, tail color, and predator escape in <i>Eumeces</i> (Lacertilia: Scincidae): age-specific differences in costs and benefits The change comes from the same pigment cells maturing, not from growing new ones, so the switch costs the lizard little.27PubMed Central. Lizards exploit the changing optics of developing chromatophore cells to switch defensive colors during ontogeny
In your yard, a striped skink with a vivid blue tail is almost always young. A plain brown lizard with faded stripes in the same spot may be the same species grown up. Because the change is gradual, you may also see in-between lizards with a dull, darker blue or gray tail. Those are teenagers, not a different species. A brown or gray tail on a lizard with a stubby regrown tail doesn’t mean the lizard has aged, since regrown tails often differ in color from the original.
Some adult males gain color of a different kind. Adult male broad-headed skinks develop bright orange heads in the spring breeding season, and the orange fades after the season, along with fighting and courtship.28Journal of Herpetology. Induction of Orange Head Coloration and Activation of Courtship and Aggression by Testosterone in the Male Broad-Headed Skink (Eumeces laticeps) An orange-headed adult in spring is a breeding male, not a different lizard. In southeastern five-lined skinks, brighter heads go with higher testosterone.29Amphibia-Reptilia. Secondary sexual coloration is related to white blood cell counts and testosterone in male southeastern five-lined skinks (Plestiodon inexpectatus)
How to Tell the Look-Alike Skinks Apart
Color won’t separate young skinks, since several species share the same black body, yellow stripes, and blue tail. Scale arrangements stay the same as the lizard grows, so they remain useful even after the blue and stripes have faded.
The most reliable clue is the scales along and just behind the upper lip.30Transactions of the Kansas Academy of Science. Meristic Variation in Kansas Broad-Headed Skinks (Plestiodon laticeps) and Common Five-Lined Skinks (P. fasciatus) To count them, find the row of scales running along the upper lip, then look at the scales directly behind it, near the corner of the mouth. Broad-headed skinks have one small scale behind the lip line, rarely two, or none.31HERPING VIRGINIA. Plestiodon Skinks — Getting it Right! Southeastern five-lined skinks have two medium-sized ones, and common five-lined skinks have two large ones.32HERPING VIRGINIA. Plestiodon Skinks — Getting it Right! Check the side of the head in good light, because shadows and a tilted head can make two scales look like one.
The second clue is on the back. Common five-lined skinks almost always have 3 scale rows between the middle stripe and the side stripe on the lower back, while southeastern five-lined skinks have four or five rows.33HERPING VIRGINIA. Plestiodon Skinks — Getting it Right! The two features work best together, and a single lizard may not match the field guide exactly.34Transactions of the Kansas Academy of Science. Meristic Variation in Kansas Broad-Headed Skinks (Plestiodon laticeps) and Common Five-Lined Skinks (P. fasciatus)
You don’t need to handle the lizard. Take a sharp close-up phone photo of the side of the head, zoom in on the lip line, and count scales from the picture. Then upload it to a regional herp group or iNaturalist for confirmation.
Where Skinks Live and How They Spend the Day
Skinks control body temperature by moving between sun and shade, so warmth shapes where they live.35Current Herpetology. Seasonal Change of Habitat Use and Thermal Ecology of Far East Five-Lined Skink, Plestiodon finitimus On cool mornings a skink basks in a sunny patch until its body is warm enough to move quickly, then forages nearby. In midday heat it retreats to shade or cover, so summer activity often shifts to mornings and afternoons. A skink in your yard is usually near both a sunny spot and a hiding place, such as a woodpile beside a patio.
Common five-lined skinks avoid areas with more than half the ground shaded by canopy for much of the season.36Lakehead University Repository. Habitat selection in the Common Five-lined Skink near the northern extent of its range Some species favor thick rocks and patches of rock cover, using rocks that stay cool at midday.37Simon Fraser University. Microhabitat Selection of the Western Skink (Plestiodon skiltonianus) in the Okanagan Region of British Columbia In some regions they use forest edges in spring and fall and move deeper into woods in midsummer.38Current Herpetology. Seasonal Change of Habitat Use and Thermal Ecology of Far East Five-Lined Skink, Plestiodon finitimus
For the best chance of seeing one, look on sunny mornings and midday on warm days in spring and summer, around woodpiles, stone walls, rotting logs, and the edges of decks. They disappear for winter and reappear in spring warmth.
Skinks eat insects and other small invertebrates, such as crickets, spiders, beetles, and caterpillars, found in leaf litter and under boards. They hunt by flicking the tongue to pick up prey scents.39Ethology Ecology & Evolution. Elevated tongue-flicking and biting by the insectivorous lygosomine skink Mabuya macularia to prey, but not plant, chemicals They are active hunters, poking into crevices rather than ambushing from one spot. After a bite, a skink flicks its tongue faster to relocate prey that escaped.40PubMed. Elevation in tongue-flick rate after biting prey in the broad-headed skink, Eumeces laticeps
Are Blue-Tailed Skinks Dangerous to People or Pets
Skinks are not venomous and rarely bite people. A grabbed skink may pinch, but its mouth is small and the bite rarely breaks the skin. If it does, wash the spot with soap and water as you would any small scratch. A skink is much more likely to flee or drop its tail. They also eat garden insects, so they are useful to have around.
The one concern is ticks. In the Southeast, most broad-headed and southeastern five-lined skinks carried young blacklegged ticks, the Lyme disease tick.41Springer Link / PubMed Central. Parasitism of lizards by immature stages of the blacklegged tick, Ixodes scapularis (Acari, Ixodidae) The ticks clustered behind the ears and in the armpits.42Springer Link / PubMed Central. Parasitism of lizards by immature stages of the blacklegged tick, Ixodes scapularis (Acari, Ixodidae) Wash your hands after touching one and check yourself for ticks.
If one gets inside, stay calm. Place a cup over it, slide paper underneath, and release it near cover outside.
To make your yard skink-friendly, leave a rock pile or log in a sunny spot and limit pesticides that kill their insect food. Keep cats indoors, since cats catch many skinks.
Keeping a Blue-Tailed Skink as a Pet
The pet-store Pacific species can be kept with the right setup. A single Pacific blue-tailed skink needs at least an 18 by 18 by 24 inch tall enclosure.43Dubia.com. Pacific Blue-Tailed Skink Care Sheet It needs UVB lighting, a basking spot near 95°F, and humidity around 60-80% by day.44Dubia.com. Pacific Blue-Tailed Skink Care Sheet Don’t house males together, or males with females unless breeding.45Dubia.com. Pacific Blue-Tailed Skink Care Sheet
The height matters because the species climbs, so give it branches, bark, and plants to climb on and hide behind. The tank should have a warm side with the basking spot and a cooler side. Use a substrate that holds moisture, such as coconut fiber or soil, and mist it to keep humidity in range.
Pet skinks eat live insects such as crickets and small roaches, dusted with calcium to keep bones healthy. Provide a shallow water dish and mist the enclosure, since these tropical lizards drink water droplets. UVB output fades over time, so replace bulbs on the maker’s schedule even if they still glow.
They are skittish and best left alone rather than handled often.46Dubia.com. Pacific Blue-Tailed Skink Care Sheet Captive-bred skinks are much calmer than wild-caught ones, so choose captive-bred if you can.47Reptile Cymru. Pacific Blue Tailed Skink Care Guide
Wild backyard skinks should stay wild. Wild-caught lizards stress easily and often decline in captivity, and they need sun, warmth, and live insects that are hard to supply. Enjoying them outside is easier and better for the lizard.