Herpetology Notes, volume 10: 673-674 (2017) (published online on 23 November 2017)
The swimming behaviour of Tzabcan Rattlesnake, Crotalus tzabcan Klauber, 1952 (Squamata: Viperidae)
Rubén Alonso Carbajal-Márquez1,2,* and J. Rogelio Cedeño-Vázquez1
Rattlesnakes are known to be terrestrial, and are SEMARNAT-2010 (Lee, 1996; Diario Oficial de la generally found in the dryer zones of the areas where Federación, 2010; Acevedo et al., 2014). Despite its they occur. However, some species are known to live relative wide distribution, little information is available near water or marshy areas, and seasonally flooded on the natural history and behaviour of this elusive zones (e.g. Crotalus polystictus, Sistrurus catenatus), species. Herein we describe the swimming behaviour of but unlike natricines they should not be considered semi- C. tzabcan to cross a geographical barrier. aquatic (Campbell and Lamar, 2004). Some species are anecdotally reported to be good swimmers and some During field work, on 9 August 2013, the second will freely enter water, including C. atrox, C. durissus, author found a juvenile male C. tzabcan (snout–vent C. horridus, C. lepidus, C. ruber, C. stephensi, C. viridis, length 364 mm, total length 399 mm; Fig. 1), swimming C. oreganus, and S. miliarius; while C. adamanteus in open water in the middle of the Chichankanab is found often swimming at sea between the keys in lagoon, Municipality of José María Morelos, Quintana Florida (Klauber, 1972; Armstrong and Murphy, 1979; Roo, México (19.856650° N, -88.763731° W, WGS84, Campbell and Lamar, 2004 [and references therein]). elevation 3 m; Fig. 2). The rattlesnake covered a total To date there are few documented events describing swimming distance of ca. 450 m, from west to east, and this behaviour in rattlesnakes (Warning and Covy, swam in lateral undulatory motion, and was found almost 2016).���������������������������������������������� � at the middle of the lagoon, where the coordinates were can cross geographical barriers as formidable as rivers taken to serve as reference to measure the distance to the and lakes (e.g. C. durissus [Ferrante et al., 2015], C. shore. The specimen was deposited in the herpetological viridis [Warning and Covy, 2016]). The reason to swim collection at El Colegio de la Frontera Sur (ECOSUR) at could be to escape from predators, or danger such as Chetumal, Quintana Roo, México (ECO-CH-H-2954). fire, floods, and also for dispersal, so this behaviour is an important survival strategy for terrestrial snakes (Klauber, 1972). Crotalus tzabcan is a large, stout snake, endemic to the Yucatán Peninsula, and listed in the Red List of IUCN as least concern (LC), and in the middle portion of the high vulnerability category (16) in the Environmental Vulnerability Score (Wilson et al., 2013), and not considered by the Mexican law in the NOM-059-
1 El Colegio de la Frontera Sur, Departamento de Sistemática y Ecología Acuática, Unidad Chetumal, Avenida Centenario Km 5.5, 77014, Chetumal, Quintana Roo, México 2 Conservación de la Biodiversidad del Centro de México, Figure 1. Juvenile specimen of Crotalus tzabcan (ECOCH- A.C. Andador Torre de Marfil No. 100, C.P. 20229, H-2954), swimming in open water at the middle of the Aguascalientes, Aguascalientes, México Chichankanab lagoon, Quintana Roo, México. Photo by J. * Corresponding Author e-mail: [email protected] Rogelio Cedeño-Vázquez. 674 Rubén Alonso Carbajal-Márquez and J. Rogelio Cedeño-Vázquez
Figure 2. Map showing locality where the Crotalus tzabcan was found in the middle of the Chichankanab lagoon (black dot), and the location of the lagoon in relation to the Yucatán Peninsula, México (inset).
The most of the Yucatán Peninsula area does not have nativas de México de flora y fauna silvestres – Categorías de any surface water currents and has a flat topography riesgo y especificaciones para su inclusión, exclusión o cambio with low elevation of the terrain, and there are several – Lista de especies en riesgo, 30 de diciembre de 2010. ��������� at: http://www.profepa.gob.mx/innovaportal/file/435/1/NOM_ cenotes and lagoons, as well as sporadic floods due to 059_SEMARNAT_2010.pdf. Accessed on 24 October 2016. hurricanes occurring in the region. Thus, the observed Ferrante, L., Menegucci, R., Machado, I. F. (2015): ������� swimming behaviour in C. tzabcan may be an important History Notes: Crotalus durissus (South American Rattlesnake). survival strategy. This observation also supports other Swimming behavior to cross geographical barrier. Herpetological anecdotal encounters of this behaviour in rattlesnakes as Review 46: 640. a strategy to cross geographical water barriers. Klauber, L. M. (1972): Rattlesnakes: Their Habits, Life Histories, and Influence on Mankind. 2 Volumes. University of California Press, Berkeley, California, United States. Acknowledgements. We thank to Jonathan Campbell for the pre- Lee, J.C. (1996): The Amphibians and Reptiles of the Yucatán peer review. Permits were provided by Dirección General de Vida Peninsula. Ithaca, USA, Comstock Publishing Associates, Silvestre SEMARNAT (SGPA/DGVS700950/16). Cornell University Press. Warning, N., Covy, N. (2016): Natural History Notes: Crotalus References viridis (Prairie Rattlesnake). Behavior/ Long distance swimming. Acevedo, M., Johnson, J., Ariano-Sánchez, D. (2014): Crotalus Herpetological Review 47: 145. tzabcan. The IUCN Red List of Threatened Species 2014 Wilson L. D., Mata-Silva, V., Johnson, J. D. (2013): A conservation [online] Available at: