Atlas Journal of Biology 2023, pp. 759–767 DOI: https://doi.org/10.5147/ajb.vi.237 A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) Coiling During Male-Male Combat in Snakes: Differences Be-Coiling During Male-Male Combat in Snakes: Differences Be- tween Vipers and Other Groups, and Between Constrictors and tween Vipers and Other Groups, and Between Constrictors and Non-ConstrictorsNon-Constrictors Ishmel J. Lock, Kaitlin E. Zalewski, and Philip J. Senter* Department of Biological and Forensic Sciences, Fayetteville State University, Fayetteville, NC 28301, USA Received: November 17, 2022 / Accepted: February 20, 2023 __________________________________________________ * Corresponding author: psenter@uncfsu.edu 759 AbstractAbstract During male-male combat (MMC) in snakes, combatants of-During male-male combat (MMC) in snakes, combatants of- ten coil around each other. To determine whether there are ten coil around each other. To determine whether there are differences in this behavior between different snake groups, differences in this behavior between different snake groups, we examined video footage of 100 instances of MMC in 49 we examined video footage of 100 instances of MMC in 49 snake species from six families. Results show that in Viperi-snake species from six families. Results show that in Viperi- dae, MMC involves smaller numbers of loops than in the oth-dae, MMC involves smaller numbers of loops than in the oth- er three clades considered here (Pythonidae+Loxocemidae, er three clades considered here (Pythonidae+Loxocemidae, Elapidae+Pseudoxyrhophiidae, and Colubridae). In Viperi-Elapidae+Pseudoxyrhophiidae, and Colubridae). In Viperi- dae, coiling also seems to be an accidental result of other dae, coiling also seems to be an accidental result of other movements and does not involve coil tightening, whereas movements and does not involve coil tightening, whereas in the other three clades it appears to be deliberate and is in the other three clades it appears to be deliberate and is often enhanced by coil tightening. The duration of coiling is often enhanced by coil tightening. The duration of coiling is shorter in the clade Elapidae+Pseudoxyrhophiidae (most of shorter in the clade Elapidae+Pseudoxyrhophiidae (most of which are non-constrictors) and Viperidae (non-constrictors) which are non-constrictors) and Viperidae (non-constrictors) than it is in Colubridae (many of which are constrictors) and than it is in Colubridae (many of which are constrictors) and the clade Pythonidae+Loxocemidae (constrictors). It is also the clade Pythonidae+Loxocemidae (constrictors). It is also shorter in non-constricting colubrids than in constricting shorter in non-constricting colubrids than in constricting colubrids, although the number of loops does not differ be-colubrids, although the number of loops does not differ be- tween the two groups. We conclude that coiling is of lesser tween the two groups. We conclude that coiling is of lesser importance for MMC in Viperidae than in the other three importance for MMC in Viperidae than in the other three clades, and that maintaining loops during MMC is of lesser clades, and that maintaining loops during MMC is of lesser importance in non-constricting groups than in constrictors. importance in non-constricting groups than in constrictors. These results show that differences in the amount of coiling These results show that differences in the amount of coiling during MMC in snakes follow phylogenetic lines. The videos during MMC in snakes follow phylogenetic lines. The videos used in this study were collected from social media and dem-used in this study were collected from social media and dem- onstrate that social media can be useful in collecting data for onstrate that social media can be useful in collecting data for scientific studies.scientific studies. Keywords:Keywords: Behavior; combat; constriction; social media; Vi- peridae. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecom- mons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the origi- nal work is properly cited. IntroductionIntroduction In snakes of the clade Afrophidia (the clade that is phylo- genetically bracketed by the boa and python clade and the clade Caenophidia—see Vidal et al., 2007), males engage in a combat ritual that often involves combatants coiling around each other and raising their foreparts, with each combatant attempting to push the other’s foreparts down (Carpenter, 1977; Senter et al., 2014; Abu Baker et al., 2021; Senter, 2022). Detailed descriptions of male-male combat (MMC) have been published for numerous snake species (reviewed in Carpen- ter, 1977; Shine, 1978, 1994; Senter et al., 2014; Abu Baker et al., 2021; Senter, 2022), but the number of loops in the coil is usually not reported. In published illustrations of MMC in snakes, the number of loops is usually as few as one to three in members of Vi- peridae (Shaw, 1948; Carpenter et al., 1976; Carpenter, 1977; Nishimura et al., 1983; Andrén, 1986; Schuett and Gillingham, 1989), whereas it is often greater than three in members of other families (Fleay, 1951; Bogert and Roth, 1966; Turner, 1992; Almeida-Santos et al., 1998; Muniz-da-Silva et al., 2013; Guedes et al., 2019; Valencia et al., 2020; Abu Baker et al., 2021). If this difference is due to a tendency among vipers to use fewer loops during MMC, and not just an artifact of having been photographed at moments when fewer loops were used than is usual for vipers, then coiling may be a com- ponent of MMC that is of lesser importance in Viperidae than in other snake clades. If so, this would be a major behavioral difference in MMC between vipers and other snakes. Such a difference would be an aspect of the evolution of snake be- havior that has not previously been reported. We therefore sought to determine whether vipers use fewer loops during MMC than is the case in other snake clades, by examining footage of MMC in vipers and other snakes. Coiling is an integral part of constriction, and previous studies have recorded that at least some snakes that use constriction to dispatch prey also employ active constriction during MMC (Martin, 1976; Barker et al., 1979; Guedes et al., 2019). We therefore also sought to determine whether differ- ences exist in the degree of coiling during MMC in constric- tors versus non-constrictors. Materials and MethodsMaterials and Methods VideosVideos Previous studies have demonstrated that social media can be useful in the collection of data for scientific study (Miranda et al., 2016; Liberatore et al., 2018; Paterson, 2018; Maritz and Maritz, 2020; Abu Baker et al., 2021). Applying this principle, we searched YouTube (www.youtube.com) for footage of MMC in snakes. Many YouTube videos of snakes have mis- leading titles in which the species is misidentified, courtship is mistaken for combat (or vice versa), or an interaction is misidentified as combat when one snake is merely treating the other as an inanimate obstacle during locomotion in a confined space. We were therefore careful to include a video in the study only if we could confirm (or correct) the species identification, and only if it recorded combat. Combat can be distinguished from courtship in afrophidian snakes in that it usually includes attempts by the combatants to push down each other’s raised heads (in non-lampropeltine snakes) or to pin each other’s heads to the ground (in lampropeltines) (Senter, 2022). In contrast, courtship usually lacks such ele- ments and includes a different suite of behavioral elements that usually includes chin-rubs and jerking of the head or body, often with the male performing such behaviors while his head moves along the dorsum of the female toward her anterior (Senter, 2022). As shown in Table 1, the footage included in the study comprises 100 instances of MMC in snakes of 49 species in six families: 29 instances in the fam- ily Viperidae, one instance in the family Loxocemidae, 12 in- stances in the family Pythonidae, 18 instances in the family Elapidae, one instance in the family Pseudoxyrhophiidae, and 39 instances in the family Colubridae. AnalysisAnalysis We compared both the number of loops and the duration of coiling during MMC between Viperidae and three other clades: Pythonidae+Loxocemidae (henceforth, P+L for con- cision), Elapidae+Pseudoxyrhophiidae (henceforth, E+P for concision), and Colubridae. We considered Pythonidae and Loxocemidae together as a single clade, because the two are closely related (Reynolds et al., 2014). Likewise, we consid- ered Elapidae and Pseudoxyrhophiidae together as a single clade, because the two are closely related (Zaher et al., 2019). To count the number of loops in each instance of MMC, we considered a single loop to be a complete turn (360º, as viewed down the long axis) of one snake’s body around the other snake’s body (Fig. 1). During MMC, the number of loops continuously changes as the snakes roll about their long axes, generating new loops near the head while uncoiling near the tail, and it occasionally happens that coiled snakes suddenly decouple with a violent whipping motion, reducing the number of loops to zero. In our comparison of the num- ber of loops, we therefore considered only the maximum number of loops in each video (Table 1). For each of the four clades, we calculated the mean and standard deviation of the maximum number of loops among the included instances of MMC (Table 2). To determine whether a significant difference exists in the maximum number of loops between clades, we ran a one-way ANOVA. To compare the duration of coiling between clades, we first calculated values that we called A, B, and C. For each clade, A is the total duration of all MMC footage in all the included videos of that clade, added together. For each clade, B is the total duration of MMC footage with coiling, in all the included videos of that clade, added together. For each clade, C is the total duration of MMC footage without coiling, in all the in- cluded videos of that clade, added together. For each clade, B / A × 100% = the percentage of MMC footage in which the combatants are coiled. We recorded that percentage for each clade in Table 2. To determine whether a significant differ- ence exists in that percentage between clades, we used the Pearson chi-squared test to compare A and C between each pair of clades (Table 3). To determine whether our data reveal a difference in the degree of coiling between colubrids that use constriction to dispatch prey (in our sample: Dolichophis, Hierophis, Lam- propeltis, Pantherophis, Pituophis, Spilotes, Zamenis) and non-constricting colubrids (in our sample: Dispholidus, Dry- marchon, Masticophis, Philothamnus, Ptyas), we repeated the analyses delineated above, comparing those two groups of colubrids. We did not repeat the analyses to compare constricting vs. 760 A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) Figure 1. Figure 1. Method of counting loops. The white snake is coiled around the gray snake with four loops. The smaller bracket shows one loop of the white snake around the gray snake. The larger bracket shows 1.5 loops of the white snake around the gray snake. 761 Table 1. Table 1. Data on coiling during male-male combat in snakes, in the videos used in this study. DCoi = Duration of coiling in the footage. DCom = Duration of combat in the footage. MNC = maximum number of loops in the footage. A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) Family Species MNC D Com D Coi Reference (author and year) Xenopeltidae Xenopeltis unicolor 2 18 s 18 s Xtclueck, 2009 Pythonidae Aspidites melanocephalus 5 123 s 123 s NQ Dry Tropics NRM, 2016 Morelia spilota > 2 51 s 3 s Afg Boii, 2018 Morelia spilota > 3 141 s 94 s TomoNews US, 2016 Morelia spilota 4 20 s 20 s Browne Snake Removals, 2014 Morelia spilota > 3 105 s 30 s Coldblooded Revolutions, 2015 Morelia spilota 5 37 s 37 s Andre, 2016 Morelia spilota 4 146 s 146 s Forgreenies, 2021 Morelia spilota 6 118 s 118 s Noosafifi, 2016 Morelia spilota 7 639 s 639 s Tisdall, 2017 Morelia spilota 5 50 s 50 s New York Post, 2018 Morelia spilota 6 46 s 46 s Linnett, 2014 Morelia spilota 6 555 s 555 s Majikfaerie, 2016 Viperidae Agkistrodon contrortrix and A. piscivorus 1 200 s 30 s Living Alongside Wildlife, 2016 Agkistrodon contortrix 0 96 s 0 s Louisiana Amphibian and Reptile Enthusiasts, 2018 Agkistrodon piscivorus 1 136 s 4 s Water Possum, 2015 Agkistrodon piscivorus 0 104 s 0 s Bruggemann, 2017 Bitis arietans 0 93 s 0 s Kruger Sightings, 2016 Bitis arietans > 2 226 s 10 s Cape Snake Conservation, 2017 Causus defilippi 0 12 s 0 s Williams, 2016 Daboia palaestinae 0 165 s 0 s Reptiles, 2020 Daboia russelii > 2 83 s 4 s (very loose loops) Searider1949, 2020 Macrovipera lebetina 3 123 s 60 s CityFreePress, 2019 Montivipera xanthina 1 30 s 3 s Gkousios, 2020 Crotalus adamanteus 0 104 s 0 s Browning, 2019 Crotalus atrox > 3 624 s 120 s Ringo999999, 2009 Crotalus atrox 2 54 s 3 s Dana, 2010 Crotalus atrox 0 83 s 0 s FOX 5 Atlanta, 2016 Crotalus atrox 3 254 s 10 s Moser, 2018 Crotalus atrox 2 65 s 2 s SeanBlue622, 2011 Crotalus durissus 2 88 s 76 s Franco, 2015 Crotalus horridus 3 75 s 68 s Bauer, 2020 Crotalus horridus 2 228 s 10 s ThatAnimalGuy, 2018 Crotalus mitchellii 0 24 s 0 s Desert Museum, 2015 Crotalus oreganus 3 57s 50s Nature Picture Library, 2019 Crotalus oreganus 0 28 s 0 s San Jacinto Trail Report, 2017a Crotalus oreganus 2 33 s 6 s San Jacinto Trail Report, 2017b Crotalus oreganus 2 69 s 62 s Crabbe, 2018 Crotalus ruber 1 35 s 1 s Greg L, 2014 Crotalus viridis 3 73 s 73 s Paul Goins, 2014 Crotalus viridis 2 51 s 30 s Joshua Anderson, 2017 Sistrurus miliarius 2 417 s 165 s Crotalusco, 2008 762 Table 1. Table 1. Continued. A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg )Family Species MNC DCom DCoi Reference (author and year) Elapidae Demansia psammophis 10 129 s 129 s Still waters, 2012 Demansia vestigiata 3 68 s 68 ParksAustralia, 2013 Dendroaspis angusticeps 8 30 s 30 s Best of Africa, 2017 Dendroaspis angusticeps 9 880 s 540 s Beach Bumz, 2016 Dendroaspis polylepis 5 65 s 50 s Kruger Sightings, 2015 Dendroaspis polylepis 5 71 s 25 s Kruger Sightings, 2017 Micrurus frontalis 10 137 s 137 s Peret, 2017 Micrurus ibiboboca 6 47 s 47 s Kemp, 2015 Naja mossambica 3 185 s 50 s Daily Mail, 2018 Naja naja > 7 530 s 180 s Kumar, 2018 Notechis scutatus 5 98 s 27 s Snake Master, 2019 Ophiophagus hannah 4 73 s 30 s Madras Cr. Bank Trust, 2019 Ophiophagus hannah 1 40 s 1 s Felis Creations TV, 2014 Ophiophagus hannah > 7 757 s 60 s Dinkelman, 2018 Pseudechis guttatus 6 51 s 51 s MH Outdoors, 2019 Pseudechis porphyriacus 5 98 s 48 s Maximus Marcus, 2017 Pseudechis porphyriacus > 15 183 s 80 s Caters Clips, 2019 Pseudonaja textilis > 3 1384 s 300 s Meek-and-wild, 2016 Pseudoxyrhophiidae Leioheterodon madagascariensis 10 219 s 166 s Trebbor Frog, 2015 Colubridae Dispholidus typus > 8 64 s 64 s Nathan, 2020 Dolichophis jugularis > 5 158 s 158 s Reptiles, 2021a Dolichophis jugularis ? 17 s 17 s Reptiles, 2021b Dolichophis jugularis 4 20s 19 s Reptiles, 2021c Dolichophis jugularis 5 ? ? Reptiles, 2021d Dolichophis jugularis 5 103 s 103 s Reptiles, 2021e Dolichophis jugularis 5 14 s 14 s Reptiles, 2021f Dolichophis jugularis 5 12 s 12 s Reptiles, 2021g Dolichophis jugularis 4 23 s 23 s Reptiles, 2021h Dolichophis jugularis > 3 97 s 97 s Reptiles, 2021i Dolichophis jugularis 4 36 s 36 s Reptiles, 2021j Drymarchon corais 0 22 s 0 s GeorgiaWildlife, 2014 Drymarchon corais 0 48 s 0 s Smith, 2011 Hierophis viridiflavus 9 314 s 296 s Bramham, 2008 Hierophis viridiflavus > 6 92 s 60 s Gary and Rachel, 2015 Hierophis viridiflavus 4 164 s 164 s Canary Honey, 2014 Lampropeltis californiae 0 118 s 0 s Wetherbee, 2017 Lampropeltis californiae 6 181 s 181 s Douglas Collins, 2016 Lampropeltis getula getula 11 48 s 48 s Cimarronsc, 2008 Lampropeltis holbrooki 5 184 s 152 s Martin, 2016 Lampropeltis triangulum > 3 120 s 20 s lukeovcrashcourse, 2017 Lampropeltis triangulum 2 153 s 153 s Vegged Out, 2020 Masticophis flagellum 0 164 s 0 s Favor, 2018 Masticophis flagellum 7 196 s 182 s Jacquiisaacson, 2008 Pantherophis alleghanensis > 5 247 s 40 s Lewis, 2014 Philothamnus semivariegatus 4 17 s 16 s Marais, 2013 Pituophis catenifer > 5 60 s 25 s Easter, 2016 Pituophis catenifer 0 61 s 0 s Webetubing, 2007 Pituophis catenifer 3 91 s 91 s Brennadl, 2019 Pituophis catenifer 6 776 s 776 s Robinson, 2014 Ptyas mucosus > 5 351 s 351 s Nilaview, 2015 Ptyas mucosus > 4 143 s 20 s Nat Geo Wild, 2018 Ptyas mucosus 7 22 s 22 s Randadath, 2012 Ptyas mucosus 0 44 s 0 s Krishnan, 2016 Ptyas mucosus 7 124 s 124 s Chavhan, 2015 Ptyas mucosus 5 129 s 119 s Dhinith S, 2018 Ptyas mucosus 5 121 s 113 s Reddy, 2020 Spilotes pullatus 8 154 s 154 s Mebert, 2017 Zamenis longissima 5 618 s 420 s Living Zoology, 2020 763 non-constricting members of E+P, due to a low sample size of constricting species in our sample of the clade. The E+P foot- age used here includes one instance apiece of MMC in two elapid species that are known to use constriction to dispatch prey: Pseudonaja textilis and Demansia psammophis (Shine and Schwaner, 1985). However, in the latter species, only juveniles are known to constrict prey (Shine and Schwaner, 1985), which reduces our sample size of videos of E+P species that constrict prey as adults, to only one video. ResultsResults During the collection of data from videos, it became evi- dent that coiling in vipers is often an accidental result of the movements involved in the combat dance, that coil tighten- ing is rare, and that active attempts to maintain a coil are also rare. In contrast, coiling in the other clades often appears to be deliberate, coil tightening is common, and the combat- ants often actively attempt to maintain large numbers of loops around each other, especially posteriorly. As shown in Table 2 and Fig. 2, the maximum number of loops per instance of MMC tends to be lower in the Viperidae than in the other three clades (x̅ = 1.4 in Viperidae; x̅ = 4.5 in P+L; x̅ = 6.4 in E+P; x̅ = 4.5 in Colubridae) (Table 2). One-way ANOVA revealed that a significant difference ex- ists in the mean number of loops between at least two clades (F(3, 95) = 18.9407, p = 1.0389e-09). Tukey’s HSD test for multiple comparisons found that the mean number of loops is significantly different between Viperidae and P+L (p = 0.0011826 < 0.01), between Viperidae and E+P (p = 0.0010053 < 0.01), between Viperidae and Colubridae (p 0.0010053 < 0.01), and between E+P and Colubridae (p = 0.0199122 < 0.05). It found no significant difference in the mean number of loops between P+L and E+P (p = 0.0994088) or between P+L and Colubridae (p = 0.8999947). Pearson’s chi-squared test found that between every pair of clades considered here, there is a significant difference in the duration of coiling during MMC (Table 3). Our analysis uncovered no significant difference in the A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) A tla s Jo ur na l o f B io lo gy - IS SN 2 15 8- 91 51 . P ub lis he d By A tla s Pu bl is hi ng , L LC (w w w .a tla s- pu bl is hi ng .o rg ) Table 2. Table 2. Data on coiling during MMC for each group. Table 3. Table 3. Results of Pearson’s chi-squared tests comparing A and C (see Materials and Methods) between pairs of clades. Figure 2. Figure 2. Box-and-whisker graph of maximum number of loops in each instance of MMC, for each clade. Outliers are represented by small circles beyond the box and whisker. 764 number of loops between constricting and non-constricting colubrids. For the maximum number of loops per instance of MMC, the mean is 4.0 in non-constricting colubrids and 4.72 in constricting colubrids (Table 2). One-way ANOVA found no significant difference between the maximum number of loops between the two groups (F = 0.6461, p = 0.4268). How- ever, Pearson’s chi-squared test found a significant difference in the duration of coiling between constricting and non-con- stricting colubrids (Χ2 = 50.4899, p < 0.0001). DiscussionDiscussion Previous studies have shown that there are differences in MMC among different clades of snakes. For example, in the colubrid clade Lampropeltini, high head-raising (present in other afrophidian clades) is absent from the MMC repertoire, and dorsal bowing of the body (absent in other afrophid- ian clades) is present (Abu Baker et al., 2021; Senter, 2022). Biting during MMC is also more prevalent in Lampropeltini that it is in other snake clades (Abu Baker et al., 2021; Senter, 2022). Also, MMC is often absent in snake clades that subdue prey by means other than venom or constriction (Schuett et al., 2001). However, previous studies have not explored dif- ferences in the degree of coiling between snake clades. The results of this study therefore elucidate an aspect of snake MMC that has not previously been elucidated. As this study shows, the lesser importance of coiling in vipers is a real dif- ference in MMC between Viperidae and other snake clades. Furthermore, this study shows that the duration of coiling during MMC differs between snake groups, with the highest durations occurring in constrictors (Pythonidae+Loxocemidae and colubrid constrictors) and lower durations in E+P and non-constricting colubrids. This study is the first to document and quantify these differences. As such, it adds to current knowledge of variation in MMC across the clade Serpentes. It is interesting that in applying constriction to their opponents, constrictors incorporate their main prey-killing technique into MMC. In contrast, vi- pers usually do not incorporate their main prey-killing tech- nique (a venomous bite) into MMC (Senter, 2022). It is also interesting that in colubrid MMC, constrictors remain coiled longer than non-constrictors but do not use a greater num- ber of loops than non-constrictors. This suggests that if coil- ing during MMC has become reduced through evolution in non-constricting colubrids, the duration of coiling is more vulnerable to evolutionary reduction than is the number of loops in a typical coil. It further suggests that those two parameters may undergo separate evolutionary trajectories and are therefore not constrained to evolve in tandem. ConclusionsConclusions Our results show that vipers tend to use fewer loops than do members of the other three clades considered here. Vi- pers also tend to spend less time coiled around opponents during MMC than do members of the other three clades con- sidered here. In short, coiling is of less importance for MMC in vipers than in other snake clades. The predominantly ac- cidental nature of the coiling in vipers and their apparent un- concern for maintaining or tightening the loops underscores the lack of importance of coiling as a component of combat in Viperidae. Our results also indicate that the maximum number of loops per instance of MMC is not significantly different be- tween P+L and Colubridae, nor between P+L and E+P. How- ever, they also indicate that the duration of coiling during MMC differs between all three of these clades, with longer durations in clades in which constriction is common (P+L and Colubridae). Likewise, our results indicate a significant differ- ence in the duration of coiling between constricting and non- constricting colubrids (the duration is longer in the constric- tors), but not in the maximum number of loops per instance of MMC. Further, this study demonstrates that social media can play an important role in the collection of data for scientific study. Previous studies that have incorporated data collection via social media have also confirmed that social media can be useful for that purpose (e.g. Miranda et al., 2016; Liberatore et al., 2018; Paterson, 2018; Maritz and Maritz, 2020; Abu Baker et al., 2021). This study provides another instance of it. Acknowledgments:Acknowledgments: We thank the photographers of the videos of the snakes in combat. We also thank the reviewers for helpful comments that improved this paper. We also thank the FSU-RISE (Re- search Initiative for Scientific Enhancement) program, which provided funding for Ishmel J. Lock. 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