The following copyrighted material is intended for individual use of the researcher, and may not be copied or distributed without written permission from the copyright holder. You may use it for non-profit scholarly purposes. The reference for this article is: Rivas, J. A., Muņoz M del C., Thorbjarnarson, J. B., Holmstrom, W. and Calle P. 1995. A safe method for handling large snakes in the field. Herpetological Review. 26: 138-139
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Restraining large and potentially dangerous reptiles for field studies without using anesthesia can pose risk to researcher as well as subject. Several techniques developed for safely handling crocodilians and venomous snakes are reviewed by Flower (1978), Almandarz (1986) and Gregory, et al. (1989). Passive restraint of large boids has not been addressed, possibly because few field investigations into their natural history have been undertaken.
In January, 1992, the authors began a long term study of ecology, behavior and conservation of anacondas, Eunectes murinus, in the Venezuelan llanos; more than two hundred anacondas ranging between 0.72 m (0.17 Kg) and 5.3 m TL (82.5 Kg) were handled during routine collection of data. In order to reduce stress on the specimen, and to minimize the number of handlers and the time required to take data from each animal, we developed the following method for safely working with anacondas.
While holding the anaconda’s jaws closed, a cotton sock of appropriate size is pulled over the snake's head . Once the snake’s snout contacted the bottom (toe) of the sock, several wrappings of plastic electrician's tape are firmly, but not tightly, secured over the sock around the snake's neck (directly behind the quadrate bone). The tape will secure the sock on the anaconda’s head. Taking care to keep the mouth closed, a second length of tape is secured, over the sock and around the snake's snout (midway between eyes and nostrils) to secure the jaws (Figure 1). At this point the anaconda can be released for measuring, scale counting, scale clipping, parasite collection, blood sampling, etc. without risk to the investigator.
Although anacondas treated in this manner frequently struck with great accuracy, they were unable to inflict injury and usually settled down after a short period. Releasing the snakes into cloth bags or steel barrels for transportation may be accomplished by removing the tape and the sock while the animal is restrained. For large snakes, the loose sock was often left in place while the animal was released into the barrel to permit handlers to move away while the snake’s vision was still compromised.
This technique for rendering anacondas safe to work with proved quite reliable. None of the snakes was able to remove the sock, nor did any bite through it. No health problems were attributed to the use of this technique. This passive restraint method could be used effectively on many species of large, non-venomous snakes in both field and captive situations.
Acknowledgments. We thank the Convention on International Trade in Endangered Species (CITES), the Ministerio del Ambiente y los Recursos Naturales Renovables (Profauna) and the Wildlife Conservation Society for financial support. We also thank Paul Andreadis and Gordon Burghardt for editorial comments on the manuscript.
ALMANDARZ, E. 1986. Physical restraint of
reptiles. In Fowler, M. E. (ed), Zoo and wild animal medicine. pp. 151-153.
W.B. Saunders Co.,
FOWLER, M. E. 1978. Restraint and handling of
wild and domestic animals.
GREGORY, P.T., G. J. DAVIES, AND J. M. MACCARTNEY. 1989. A portable device for restraining rattlesnakes in the field. Herp. Rev. 20(2):43-44