Review of: DeGregorio, Brett A., Eric J. Nordberg, Jacob E. Hill, and Katherine E. Stepanoff. "Patterns of Snake Road Mortality on an Isolated Barrier Island." 09 Feb. 2010. Web. 01 Jan. 2011.
Written by: Nicole Rinehart
In this article, published by four college students, from different colleges that came together on Bald Head Island in North Carolina to conduct research. They were to research if vehicles can have an effect on wildlife. In this article, the researchers are taking a look at five different kinds of garter snakes (Coluber constrictor, Opheodrys aestivus, Pantherophis alleghaniensis, Cemophora coccinea, and Nerodia fasciata) and of them, which species gets run over more by, in this case, golf carts. The research is being done on Bald Head Island which is an isolated barrier island. On the island, the majority of the transportation is slow-moving electric golf carts.
Aside from the island, the article states that the United States contains more than 6.4 million kilometers of roadways with 84% of land being located within 1 kilometer of a road. On an annual basis, tens to hundreds of millions of snakes are killed by vehicles on the roads within the United States. Snakes may be more prone to being run of because of their camouflage with the road but also in my experiences many people don’t care for them and thus increasing the number of snakes killed on roads relative to other wildlife.
The site they are studying, Bald Head Island, is an 800 ha barrier island which is located in southeastern North Carolina. On the island, there are approximately 35 kilometer of paved roads. There are 1000 homes on the island, with less than 200 year round residents. The island has a town ordinance that requires the natural habitat around each home must not be cleared. The section surveyed was 4.59 kilometers of a main island road by a golf cart, and they collected all snakes, dead and alive. The time and location of the snake caught was documented and then brought the snake back to the lab for processing. Once in the lab, they took a look at what kind of snake they had, what the weight and measurement was, and also sexed the snakes. They concentrated their surveys on the main road because it traverses mature maritime forest. Besides the main road, whenever staff and vehicles were available, they would go on other roads and collect all the snakes they encountered. All of the living snakes that were caught were released within a 24 hour period from the time of capture back to where they were captured. They picked this location, because to their knowledge, there hasn’t been a study done like this on a barrier island.
In this study, they collected a total 186 dead snakes of the five species between April 25th and October 1st 2009. Along with the dead snakes, they captured and marked 50 snakes of the same five species that were alive on the road. They concluded that paved roads and vehicles clearly can have negative impacts upon snake communities on their populations. After their study was done, they found that the neonates of 3 out of the 5 snakes got run over more (C. constrictor, N. fasciata, and P. alleghaniensis). They think that the neonates may have been in large numbers due to the propensity of this life stage and for erratic dispersal movements. In conclusion, they didn’t think the vehicle traffic had as much of an impact on the snakes’ mortality; it was the way the snakes moved throughout the day that they thought contributed to more snake deaths. Either way, we just have to be more cautious of what is on our roads and try to avoid anything that comes on the roads. Snakes have an impact on the environment too, so keeping them around can be a good thing for the future.
2 comments:
Nikki, this is an interesting topic. Did the article say anything about the researchers assessing the populations of each of the snakes, or was it just a study to determine which was killed by golf carts most often? It would be interesting to see what percentage of the snake populations are killed each year by roads.
I wonder what type of stresses roads put on snakes in regard to their breeding habits or day-to-day movement? I know similar studies have been done on animals such as caribou in relation to roadways.
I can honestly say I don't care too much for snakes. I don't think I would go ahead and say I would hit one on purpose, but wouldn't lose sleep over it if I accidentally hit one. It's tough to place much ecological value on a snake, but hey, they are part of the ecosystem too!
Thanks for the comment! I found this to be an interesting topic also, but I didn't do it for the fact I don't like snakes. I hope to work with them in the future, but I know also, a lot of people don't care for them. I just thought this was a clever article, and never thought research would be done on this type of thing.
If I recall right, the article did have a little bit of assessing the populations of each snake, but they were more focused on the movement patterns of each snake and putting that with which snake(s) were run over by the golf carts.
I wonder about your second question too. It would be interesting to figure the stresses for all animals and what makes them cross the road admist traffic in turn making them roadkill.
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