Research Project of tree snakes in Chamela, Jalisco, Mexico.
Although this snake is relatively abundant, until recently many aspects of the natural history of the species were unknown due, among other factors, to their morphology and type of habits, i.e. its cryptic appearance and arboreal habits, which make it very difficult to observe and locate
Unfortunately one of the snakes was depredated but thanks to the radio transmitter I could locate the animal. Although the snake was chewed by the predator the radio transmitter remained intact and functioning properly, thus making it possible to attach on another snake.
Carlos Augusto Sotelo Madrid M.S.
Arboreal snake Oxybelis aeneus is a species with a wide distribution in the Americas, can be located from Arizona in the United States, to Central and South America (Henderson and Binder, 1982). Oxybelis aeneus is commonly known as Mexican vine snake or brown vine snake. (Figure 1).
Figure 1. Oxybelis aeneus is moving through the vegetation. Note that the snake has a similar appearance to the dry branches around it. The red ellipse shows its head.
In this sense, and in order to understand the movement patterns of Oxybelis aeneus and its microhabitat characteristics, I started a research project in the Chamela Biological Station, UNAM, located on the coast of Jalisco in western Mexico. The Chamela region is dominated by small hills covered with tropical deciduous forest and stream vegetation in the valleys (Figure 2).
Figure 2. General view of the region of Chamela, Jalisco, in the dry season.
To carry out this study I used the technique of radio telemetry to monitor the activity of snakes in the field. The equipment used consisted of 8 radios with external antenna model TXB-007I, a receiver RX-TLNX and a three-element Yagi antenna, all from Telenax. Radio transmitters were placed externally in 8 adult snakes. Most transmitters functioned properly, only had a little mishap with one of them, but luckily I had the quick advice from Engineer Alex Campos, who quickly solved the problem of the transmitter and so I could use it without any problem. The intensity of the signal emitted by radio transmitters was very good, being able to trace it to distances of 130m in wooded areas and this was very helpful in locating animals (Telenax Note: Since 2013 we have this same model with approximately 5 times the signal strength under the same weight, life and price). The collapsible antenna was very useful in monitoring the animals, because sometimes it was necessary to look at the banks of streams which had a lot of vegetation, making it difficult to monitor animals (Figure 3 ).
Fig.3. Here I am tracking an Oxybelis aeneus on a lane into the jungle.
With the help of telemetry equipment it was possible to know unknown aspects of the ecology of the species (eg food, predation, interactions with other organisms, etc.), facts that could hardly have been observed without the aid of an efficient tracking system. Finally, I consider that the use of telemetry equipment, such as this acquired from Telenax, and intensive work in the field, represent the ideal tool to increase knowledge of the ecology of several species of snakes that live in our country.
Andres Garcia Ph. D. and Ricardo Ayala for the support provided during my stay at the Biology station, CONACYT for the scholarship awarded through the Post-Graduate Program in Biological Sciences at UNAM.
Henderson, R. W. and M. H. Binder. 1982. The Ecology and Behavior of Vine Snakes (ahaetulla,
Oxybelis, Thelotornis, Uromacer): A Review. Contributions in Biology and Geology Series,
Milwaukee Public Museum Press.
Additional images of the research project tree snakes
Figure 4. Carlos Madrid with a just caught Oxybelis aeneus
Figure 5. Unfortunately one of the snakes was depredated but thanks to the radio transmitter I could locate the animal. Although the snake was chewed by the predator the radio transmitter remained intact and functioning properly, thus making it possible to attach on another snake.
Figure 6 & 7. Pictures of Oxybelis aeneus with transmitter attached
Figure 8. Oxybelis aeneus
Telenax is pleased to thank Carlos Madrid M. S. for sharing this article.