Five-Lined Skink (Plestiodon fasciatus)

One of my favourite games when I was a kid (and probably now, if I played it) was Sim Safari. I’ve probably mentioned it before on this blog, I’d be shocked if I hadn’t. Anyway, the game taught me a lot about animals (though more realistically it taught me the names of some animals). One of the creatures I remember vividly is the five-lined skink. When you’d put some of them into your park they’d wiggle away like snakes and they seem to proliferate rapidly. In honour of those memories, today we’ll talk about the five-lined skink.

In contrast to what Sim Safari taught me, the five-lined skink does not live in Africa. There is a five-lined skink that lives there, known as the five-lined mabuya, but it looks nothing like the little graphic in the game. Five-lined skinks actually live in North America, from Mexico up to Southern Ontario, and are very common. They live in moist forests, preferring areas that have plenty of places for them to bask. These sites let the animals warm up from the sun so they can move around.

A male five-lined skink. In the breeding season they often get a bright orange patch under their chin. Looks pretty rad. Photo: Joe Crowley

A male five-lined skink. In the breeding season they often get a bright orange patch under their chin. Looks pretty rad. Photo: Joe Crowley

These skinks are pretty small, ranging from 12 − 21cm in length. They are, of course, characterized by the five light coloured lines that run from the animal’s head to tail. Stripes and the skink’s dark colour fade with age, with stripes eventually vanishing in older males and mature animals turning olive or grey coloured instead of black. Also notable is the bright blue colour of the tail in young skinks, which also fades with age. So I guess these animals start out looking really pretty and interesting and grow up to be plain boring grey skinks. Pretty lame.

Female skinks do a surprising amount of parental care for a reptile. Once the eggs are laid, she broods them, either lying on top of them or wrapping herself around them. When soils are drier, she covers the eggs more carefully, to prevent moisture loss. She also pees on the eggs if they get too dry, which I’m sure they appreciate. Any escapee eggs (how they get away is a mystery) are rolled back into the nest, and eggs are defended from predators. This much parenting takes a lot of work, so skinks form communal nests and leave one animal to guard the brood while others forage. Once the eggs have hatched, the female realizes how much prettier her offspring are than her, and leaves them to fend for themselves.

Come on. Come on, little one. Come on then. There you go!

Come on. Come on, little one. Come on then. There you go!

One notable feature of the skink is its ability to detach their tail in the event of an attack. They can lose their whole tail or just a tiny bit, but the idea is the wiggling, brightly coloured tail distracts the predator long enough for the skink to get away. Tail amputation is actually really interesting – most animals that do this have the tails break off between the vertebrae, when they are gripped by a predator and pressure is put on the tail. Others, though, have special ‘fracture points’ in the tail, where a contraction of tail muscles causes the tail to fall off, and constricts the arteries to prevent blood loss. Things get even grosser – some species store significant reserves in their tails, so after shedding it will return to the tail and eat it. So not cool.

Which method the five-lined skink uses, I’m not sure. But either way, it’s a pretty nifty animal, and I’m glad Sim Safari taught me something (even if it was wrong).

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