Thursday, August 4, 2016

Skinky Little Eggs


Barb was re-potting a yucca on the deck at the creek house when she found these little eggs just under the surface.  They were small and soft like reptile eggs and the pot was too high for a turtle to reach so that left the skinks and fence lizards that race around the deck.

These turned out to be Five-lined Skinks, Eumeces fasciatusMother skinks will hang around to defend their eggs* but we had to move them rather than leaving them exposed to marauding wood rats and squirrels as well as our resident Black Rat Snake.  We decided to adopt them and nestled them into potting soil in a plastic aquarium where they could live on the deck safe from predators.

Lizard eggs are thin and membranous and as such can absorb or lose water.  Soil moisture is important and more moisture tends to produce larger eggs and hatchlings.  A mother skink will cover the eggs with her body in low humidity to keep up moisture content, sometimes even urinating on the eggs.  I didn't go that far but did check the soil moisture and sprinkle it with water.

Thirty days later we found two little skinks crawling around the surface.  Once we released them, we dug into the soil and more blue tail flickered as they dug deeper to escape.  We had a total of 9 skinks out of ten eggs with no evidence of egg fragments or the missing egg. Mother skinks will eat a dead egg but she had no access to the container so its fate will remain a mystery.

Interesting research in Australia showed that at least one species of skink can deliver itself early when it senses a threat.  It was known that signals of predators sometimes prompt early hatching in frog embryos.  As reported in Science Magazine:
"Talk about hatching an escape plan. Unborn lizards can erupt from their eggs days early if vibrations hint at a threat from a hungry predator, new research shows. The premature hatchlings literally "hit the ground running—they hatch and launch into a sprint at the same time," says behavioral ecologist J. Sean Doody, who is now at the University of Tennessee, Knoxville."
Skinks are said to survive in an aquarium with adequate care for 5-10 years.  Ours are free to roam and wave their little blue tails as a thank you until they get over the blues as adults.

* Although the aquarium was moved some distance away next to a wall, we found an adult skink hiding by it several times.  Coincidence, probably as skinks run around the deck regularly, but I like to think it was mom come to visit the eggs.

Lisa Berger asked if other skinks have blue tails.  The answer is yes, all other immature skinks like the Broadhead Skink have blue tails.  Females and juveniles of these two species are hard to tell apart.  The Broadhead's upper lip has 5 scales, the Five-lined only 4.  We have had Five-lined on the deck in the past and I didn't traumatize these wiggling babies by trying to get a closeup side view.
Broadhead Skink- Count the 5 scales on the upper lip.
More information on skinks and the tale of their self-amputating tail is in this previous blog.

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