Posts Tagged ‘lizards’

A Flash of Blue

Friday, June 17th, 2011

During June and July, eggs of the Five-lined Skink (Plestiodon fasciatus) hatch, producing tiny black and white striped offspring with metallic blue tails. These small lizards are often common in yards, on logs in the forest, and on the sides of trees. When approached, they rapidly disappear into leaf litter or under a log. What we often see is just a blur of blue.

Juvenile Five-lined Skink

Juvenile Five-lined Skink

The black and white stripes fade as the skinks get older, and just after they reach sexual maturity, their tails fade to match the brown body coloration. Why are the juveniles so brightly colored in the first place, and why do they lose this coloration?

Adult female Five-lined Skink

Adult female Five-lined Skink

If you watch a young skink for a while, it will go in and out of leaf liter looking for small insects. When its body goes into the leaf litter, it will move the tail back and forth on the leaf litter. If a bird or other predator has been watching the lizard, the blue tail signals that the skink knows a predator is near and that it likely can escape if attacked. If the bird attacks anyway, it may get the tail but the lizard will escape and grow a new tail. Losing a tail doesn’t cost a young skink very much in terms of energy. So this is the answer to the first question. The bright coloration distracts a predator away form the body of the skink to the tail, which can be re-grown if lost.

As these skinks grow and lose their juvenile coloration, they tend to become cryptic. That is, they match the background colors of the forest and are much more difficult to see. They are also more experienced because they are older. Adults store fat in the tail, and that fat is used by males for reproductive related behavior, and by females, to produce eggs. As a result, losing a tail as an adult is expensive energetically and it can affect their ability to reproduce in a given year. They also can grow back their tails if they should lose them, but they might have to skip a year of reproduction. Consequently, the tail in adults is an important fat storage organ, so good reasons exist to not attract attention to it.

Amphibians and Reptiles at the SNOMNH

Thursday, September 3rd, 2009
Male Broad-headed Skink showing breeding coloration
Male Broad-headed Skink showing breeding coloration

Hello, interested readers. Herpetologists at the Sam Noble Oklahoma Museum of Natural History in Norman have been monitoring amphibians and reptiles in southeastern Le Flore County for the past year and have run across some interesting aspects of the biology of these often abundant and visible animals. We are so excited about our findings, and herpetology in general, that we decided to create this blog to keep others around the state, the nation, and the world informed.

As some of you already know, Dr. Laurie Vitt and Dr. Janalee Caldwell (us!) have spent many years studying amphibians and reptiles in the United States, Central America, South America, and a few other exotic places. We are professional researchers, but like most people who are fortunate enough to be paid for what they love to do, we started out by observing amphibians, reptiles, and other animals in their natural habitats when we were just children. So, in a sense, we never grew up! What we have learned directly from these animals is remarkable, and as you will see in the forthcoming blogs, the natural world is even stranger and more interesting than anything that we could make up.

We hope that you will join us by keeping up with our blog, and we will do our best to provide you with interesting information on these fascinating animals. For those of you who are particularly interested in amphibians and reptiles of Oklahoma, we invite you to visit our web personal pages, and more specifically, to examine the web pages that we have prepared for some of the Wildlife Management Areas (WMAs) around the state, in collaboration with the Oklahoma Department of Wildlife Conservation. We now have three WMA web pages, Packsaddle, Atoka, and Cookson, and all can be accessed from our WMA web page (http://www.snomnh.ou.edu/personnel/herpetology/vitt/WMA/index.shtml). We are working on more. We also have web pages for some of our South American research sites. So, for now, welcome to our blog, keep checking, and feast your imagination on this beautiful male Broad-Headed Skink from the Cookson Hills in NE Oklahoma.