Archive for September, 2009

What is a drift fence?

Tuesday, September 15th, 2009

One way to determine the species of amphibians and reptiles that occur in an area is to use a drift fence.  Our fences are constructed from stiff vinyl held up by pieces of rebar.  The Y-shaped design has a bucket in the center, buried flush with the ground, and two wire minnow traps on either side of the ends of the fences—see the photograph.  We have 17 of these drift fence arrays at our study site in southeastern Oklahoma.  As animals move through an area, they encounter the fence and follow it to the right or left, ending up either in the center bucket or a trap at the other end.  Drift fences must be checked every day so that animals do not spend very long in the traps. We will periodically let you know what we are finding in our traps.

We have already started some long-term studies on snakes. We use “pit-tags” to identify individual snakes so that we can follow their movements and keep records on growth. Pit-tags (passive integrated transponders) injected under the skin of snakes work like price codes on things that you purchase. We simply read each snake’s “code” with a scanner every time that we capture it. Pit-tags don’t bother the snakes at all.

A drift fence used to capture amphibians and reptiles

A drift fence used to capture amphibians and reptiles. Wooden squares are used to shade the traps from the sun, and large sponges provide moisture and protection for animals in the bucket.

More on Pygmy Rattlesnakes

Tuesday, September 15th, 2009

pygmy-juvNewborn Pygmy Rattlesnakes, which are born alive in late August or early September, are very small and dificult to observe. Nevertheless, they are venomous when they are born and they should not be handled.

Fall Arrival of Pygmy Rattlesnakes

Monday, September 14th, 2009
Pygmy Rattlesnakes are difficult to see when they are in leaf litter and their tiny rattles are difficult to hear.
Pygmy Rattlesnakes are difficult to see when they are in leaf litter, and their tiny rattles are difficult to hear.

As fall arrives, Pygmy Rattlesnakes (Sistrurus miliarius) seem to crawl out of the woodwork, showing up on porches, in garages, under cars, and in flower beds throughout much of eastern Oklahoma, as far west as Norman and Oklahoma City. These beautifully patterned, small rattlesnakes have tiny rattles that are difficult to hear, and they often do not rattle when disturbed. Like other venomous pit-vipers (snakes in the family Viperidae that have heat-sensing pits below and between the nostril and eye), these small snakes can inflict a dangerous bite. The reason that we see these snakes during the fall is that they mate at this time of year, and, as a result, males are frequently seen as they search for females. They spend much of the rest of the year hidden, often under leaf litter. Our advice is to leave these snakes alone, and if they are close to your house, move them to a different location by carefully scooping them up on a rake or shovel. Remember, they have always lived here and hopefully always will, as they are part of our natural heritage. Teach your children what they look like so that they do not handle them.

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.