Herpetology Notes, volume 13: 329-332 (2020) (published online on 20 April 2020) Male-male combat in the coralsnake Micrurus mipartitus decussatus (Duméril et al., 1854) (Squamata: Elapidae) Jorge H. Valencia1,2, Katty Garzón-Tello3,4,5, and Dan Cogălniceanu6,* Male-male combat is a ritualistic behaviour Ferguson, 1977; Shine, 1993; Greene, 1997; Almeida- widespread among snakes (e.g., Senter et al., 2014). Santos and Marques, 2002), yet they appear to be This type of behaviour is often attributed to intrasexual common phenomena described in snake species from competition for mates or breeding territories, or as around the world. Male-male combat has been reported an intersexual display (Akester, 1979). This ritual in several neotropical snakes in the last twenty years consists of interaction sequences between male snakes, (e.g., Almeida-Santos et al., 1998; Almeida-Santos and which appear to be a contest for dominance, access to Marques, 2002; Pinto et al., 2002). However, male-male copulation with a reproductive female, or associated combat records in coralsnakes of the genus Micrurus with male-biased sexual size dimorphism (Carpenter, are scarce (Missasi et al., 2017). Here we describe 1984; Almeida-Santos and Marques, 2002; Marques et for the first time male-male combat of the bicoloured al., 2013; Senter et al., 2014). The combat process may coralsnake Micrurus mipartitus decussatus from include head raises, pushing, downward pushing, closed- southwestern Ecuador. mouth strikes, body bridges or jerks, which can occur Micrurus mipartitus decussatus is a slender, medium- as consecutive, simultaneous, or independent events sized snake (maximum snout-vent length = 914 mm in (Senter et al., 2014). Nevertheless, due to the secretive females, 1014 mm in males) that inhabits a diversity nature of the great majority of snakes, observations of of habitats including lowland humid tropical forests, male-male combat behaviour are generally anecdotal, lower montane wet forests, and cloud forests (Campbell restricted to limited distribution ranges, or seen in and Lamar, 2004; Valencia et al., 2016). It occurs from laboratory experiments (Shawn, 1951; Carpenter and the Andes of western and central Colombia, part of the Colombian Cordillera Oriental, to western Ecuador and northwestern Peru, between elevations from 0–2700 m (Roze, 1996; Campbell and Lamar, 2004). The breeding season for M. m. decussatus is unknown, but it is likely to be the same as for the other subspecies of M. 1 Laboratorio de Anfibios y Reptiles, Fundación Herpetológica mipartitus. Gravid females of the Chocoan coralsnake, Gustavo Orcés, Avenida Amazonas 3008 y Rumipamba, M. m. popayanensis, were found to be gravid between Casilla 1703448, Quito, Ecuador. November and January, and oviposition occurred during 2 Red de Biología y Conservación de Vertebrados, Instituto that period (Ayerbe et al., 1998; Saldarriaga-Córdoba, de Ecología, carretera antigua a Coatepec, 91070, Xalapa, 1988). Roze (1989) reported an incubation period of Veracruz, México. 3 Vivarium de Quito, Fundación Herpetológica Gustavo Orcés, 84–94 days for M. m. decussatus. Thus, mating in these Avenida Amazonas 3008 y Rumipamba, Casilla 1703448, snakes probably occurs between August and October. Quito, Ecuador. We observed and photographed two male M. m. 4 Red de Ecoetología, Instituto de Ecología, carretera antigua a decussatus (labelled a and b in Fig. 1) at Reserva Coatepec, 91070, Xalapa, Veracruz, México. Buenaventura (3.6463°S, 79.7586°W; elevation 650 5 Asociación Veterinaria de Anfibios y Reptiles A. C., Museo m), El Oro Province, southwestern Ecuador, on 2 Viviente de Puebla, 7 Oriente 211, Col. Centro, Puebla, August 2014. The snakes were found coiled around one México. 6 Ovidius University Constanţa, Faculty of Natural and another fighting on the ground along a trail at 1500 h Agricultural Sciences, Al. Universităţii, nr. 1, corp B, and continued the behaviour for approximately 36 min. 900470, Constanţa, Romania. Throughout, they were aligned horizontally but would * Corresponding author. E-mail: [email protected] often raise as much as the first third of their bodies, 330 Jorge H. Valencia et al. Figure 1. Representative events in male-male combat behaviour in the coralsnake Micrurus mipartitus decussatus. Two males, labelled a and b in the images, were observed. (A) Body alignment. (B) Presenting venters. (C) Heads slightly raised. (D) Tails and bodies fully entwined. Photos by Dan Cogălniceanu. including heads and forebodies, off the ground to try and Male b positioned its head next to the neck of Male a for reach higher than their opponent, pushing side to side approximately 16 min. No biting, shaking, or whistling and up and down in an attempt to push their opponent’s were observed in the process. The combat concluded head to the ground. The males were entwined in a ventral when the “loser” (Male b) withdrew from the fight and position with the tail kept vertically. This behaviour was became inactive, whereas the “winner” (Male a) moved observed three times and lasted between 12 and 21 s. slowly towards the forest where he disappeared among Males writhed longitudinally and showed their venters the leaf litter. consecutively. Male a tightly entwined the anterior third Male-male combat was previously reported in of its body with the corresponding section of male b’s related species in the coralsnakes Micrurus altirostris body and forced it to the ground. The remainder of the (Almeida-Santos et al., 1998; Marques et al., 2006) bodies was only loosely entwined. Heads were slightly and M. lemniscatus carvalhoi (Missasi et al., 2017). elevated vertically, and a slight sway was observed Both species are included in the South American while the anterior body sections were moving, and triads-bearing group, one of the four phenetic groups periodically the posterior parts of the bodies also became proposed by Campbell and Lamar (2004) that also firmly entwined (Fig. 1). Sometimes the two males had include the monadal group, the bicolour group, and the their entire bodies entwined while they spun around on Central American triad-group. However, differences their bodies’ longitudinal axes while constricting each in male-combat behaviour have been observed among other vigorously. Posteriorly, Male b positioned his head species of the South American triads-bearing group anterior to the head of other male. Both males were then (M. altirostris and M. lemniscatus carvalhoi) and the inactive for 5 min. Male a entwined the anterior part of bicolour group (M. mipartitus decussatus) suggesting Male b for a period of 2 min. Before the end of combat intraspecific variation: (1) hemipenis exposure was not Male-male combat in the coralsnake Micrurus mipartitus decussatus 331 Table 1. Selected data of comparative male-male combat repertoire observed in three coralsnakes species of two different lineages. Abbreviations include sample size (N), bicolour group (B), South American triad-bearing group (T), and sexual size dimorphism (SSD).Table 1. Selected data of comparative male-male combat repertoire observed in three coralsnakes species of two different lineages. Abbreviations include sample size (N), bicolour group (B), South American triad-bearing group (T), and sexual size dimorphism (SSD). Taxa N Group Coil Body alignment and Males showing Bites Head and SSD Month Source head raised position the venter body sway Micrurus mipartitus 1 B Tail and Slightly raised and Yes, both males No Yes, but only No August This work decussatus body horizontally aligned or one male, the heads with forward consecutively or movements independently Micrurus altirostris 7 T Tail and Slightly raised and No No No No April Marques et al., 2006, body horizontally aligned, 2013; Almeida- head side to side Santos et al.,1998* while moving forward Micrurus lemniscatus 1 T Tail and Horizontal and No No No Yes June Missasi et al., 2018 carvalhoi body vertically aligned, heads side to side while moving forward * Previously identified as M. frontalis by Almeida-Santos et al. (1998). observed during combat in M. mipartitus decussatus Male combat. Herpetological Review 29(4): 242. and M. lemniscatus carvalhoi but this behaviour was Ayerbe, S., Tidwell, M.A., Tidwell, M. (1998): Observaciones observed in the triadal species M. altirostris (Almeida- sobre la Biología y comportamiento de la serpiente coral “rabo de ají” (Micrurus mipartitus). Descripción de una subespecie Santos et al., 2014); (2) ventral exposure was observed nueva. Novedades Colombianas 2: 30–41. in M. mipartitus decussatus but it was not observed in Campbell, J.A., Lamar, W.W. (2004): The Venomous Reptiles M. altirostris and M. carvalhoi; (3) heads were slightly of the Western Hemisphere. Ithaca, New York, USA, Cornell raised at some point during the combat in M. mipartitus University Press. decussatus and M. altirostris, contrasting with the pattern Carpenter, C.C. (1984): Dominance in snakes. In: Vertebrate of heads on the ground, side to side, without evidence ecology and systematics. A tribute to Henry S. Fitch, p. 195– 1 of heads raised in M. carvalhoi; and (4) a slight sway of 202. Siegel, R., Hunt, L.E., Knight, J.L., Maralet, L., Zuschlag, N.L., Eds., Museum of Natural History, University of Kansas, the heads was seen in M. mipartitus decussatus but not Lawrence, Kansas, USA. in the other species. The combat observations reported Carpenter, C.C., Ferguson, G.W. (1977): Variation and evolution of here are similar to those described for M. altirostris, stereotyped behavior in reptiles. In: Biology of Reptilia. Volume and indeed this behaviour seems common also for other 7, p. 335–554. Gans, C., Tinkle, D.W., Eds., Academic Press, species of coralsnakes (Table 1). New York, USA. Greene, H.W. (1997): Snakes: the Evolution of Mystery in Nature. Acknowledgements. We are thankful to María Elena Barragán, San Diego, California, USA, University of California Press. Paul Székely, and Eric Smith for invaluable support to the study Marques, O.A.V., Almeida-Santos, S.M., Rodrigues, M.G.