Abstract Negative interactions between humans and venomous snakes are increasing, with the World Health Organization committed to halving snakebite deaths and disabilities by 2030. Evidence‐based strategies are thus urgently required to reduce snakebite events in high‐risk areas, while promoting snake conservation. Understanding the factors that drive the adoption of snakebite prevention measures is critical for the effective implementation of snakebite management strategies. We conducted in‐person questionnaires (n = 535 respondents) with rural agricultural communities within the Thiruvarur District of Tamil Nadu, India, a national snakebite hotspot. Using a health belief model framework, we explored current snakebite prevention measures and factors impacting their adoption. The majority of respondents reported using multiple snakebite prevention measures. Perceived self‐efficacy and perceived risk frequency of snakebites were important overall predictors of future adoption, whereas education, gender, relative wealth, and current adoption were important for specific measures. Achieving international commitments to support human–snake coexistence will require collective and collaborative action (e.g., governments, donor agencies, civil society organizations, researchers, and communities) underpinned by behavioural insights and context‐specific solutions.

Cannibalism is widespread in the animal kingdom. The most common, well-known cases are found in some arthropod systems where the larger females occasionally consume the smaller males before, during, or after mating (i.e., sexual cannibalism). The killing and consumption of females by males are, on the other hand, seemingly much rarer and theoretically more difficult to explain, at least among adults, because the consumption of females would result in the loss of potential mates for males. Here, we use observations submitted to a community science reporting system to describe three instances of adult males feeding on adult females in the Montpellier snake, Malpolon monspessulanus, in the south of France. We discuss our observations in the theoretical framework of cannibalism to provide potential explanations for these observations and briefly review empirical findings of cannibalism in vertebrates, which confirms that this sex-reversed form of sexual cannibalism is rare in nature.

Snakebite envenoming is a major neglected tropical health issue. The high incidence of snakebites in tropical rural communities suggests that venomous snakes and people are often in proximity but quantitative evidence is lacking. I used radio-telemetry on a population of Russell's vipers (Daboia russelii), one of the most medically important snakes in the world, to quantify proximity between this venomous snake and people and estimate susceptibility to snakebite envenoming in India. I observed people ≤50 m of a radio-equipped viper in ~17% of 2,066 snake relocations. People were more frequently observed in proximity to Russell's vipers in January and July compared to March, but all other contrasts were statistically similar. This pattern indicates that snakebite incidence, which peaks in summer in the study area, is not particularly linked to the encounter frequency between people and vipers. However, consistent with epidemiological data plantation workers were the most at-risk part of the population. By integrating information about the locations of humans and snakes in space and time, this pioneering research highlights the need to include snake ecology into the study of the human-venomous-snake conflict, and provides a model approach to help mitigate the burden caused by venomous snakes in the rural Tropics.

Photo 1: A Russell's viper (Daboia russelii) basks in the low branches of a tree in Karnataka, India, in a water canal located right next to an agricultural field. Photo credit: Xavier Glaudas. This photograph illustrates the article “Proximity between humans and a highly medically significant snake, Russell's viper, in a tropical rural community” by Xavier Glaudas published in Ecological Applications. https://doi.org/10.1002/eap.2330

The secretive behavior and life history of snakes makes studying their biology, distribution, and the epidemiology of venomous snakebite challenging. One of the most useful, most versatile, and easiest to collect types of biological data are photographs, particularly those that are connected with geographic location and date-time metadata. Photos verify occurrence records, provide data on phenotypes and ecology, and are often used to illustrate new species descriptions, field guides and identification keys, as well as in training humans and computer vision algorithms to identify snakes. We scoured eleven online and two offline sources of snake photos in an attempt to collect as many photos of as many snake species as possible, and attempt to explain some of the inter-species variation in photograph quantity among global regions and taxonomic groups, and with regard to medical importance, human population density, and range size. We collected a total of 725,565 photos—between 1 and 48,696 photos of 3098 of the world's 3879 snake species (79.9%), leaving 781 “most wanted” species with no photos (20.1% of all currently-described species as of the December 2020 release of The Reptile Database). We provide a list of most wanted species sortable by family, continent, authority, and medical importance, and encourage snake photographers worldwide to submit photos and associated metadata, particularly of “missing” species, to the most permanent and useful online archives: The Reptile Database, iNaturalist, and HerpMapper.

Venomous snakes are a public health concern in India, where they kill tens of thousands of people annually. Russell's Vipers are the major culprit, but despite their clinical significance, there is virtually no information on their ecology. I used radiotelemetry for a 9-mo period to study the spatial and behavioral ecology of a population of Russell's Vipers (Daboia russelii) in a human-dominated rural landscape in Karnataka, India. Russell's Vipers spent a substantial amount of time in plantations, which make up a significant proportion of the landscape. Snakes were the least active in March, a dry month with the hottest monthly mean maximum temperatures recorded; and spatial activity comparatively increased in late fall-early winter and May, corresponding with the timing of mating activities and the end of the dry season, respectively. Russell's Vipers basked throughout the year, but basking behavior was more frequent in January and February, when the monthly mean minimum temperatures were the lowest. The probability of observing a snake basking increased with decreasing minimum temperatures. Similarly, the snakes were found in ambush foraging postures during daytime throughout the year, and the odds of observing diurnal foraging increased with increasing minimum temperatures and was affected by an interaction between maximum temperature and sex. Overall, the data indicate that this tropical viper actively thermoregulates and is to some extent diurnal. This study provides the first quantitative field-based natural history information on Russell's Vipers, one of the most medically important snakes in the world.

Body size is a key selected trait in many animal systems: larger size is sexually selected for in males because it confers a reproductive advantage during contest competition for access to females, and larger females are naturally selected for fecundity. Herein, we used radio‐telemetry to gather a large dataset of male–female interactions and DNA paternity analyses to characterize the intensity of sexual selection and the link between two body size metrics (body length and condition, the latter manipulated experimentally for males) and reproductive success in a population of puff adders Bitis arietans. Our multiple estimates of the intensity of sexual selection generally indicated that males experienced stronger sexual selection than females. However, the Bateman gradients did not differ by sex, despite the fact that males increased reproductive success by mating with multiple females while females did not. We also found no strong evidence that females experienced indirect fitness benefits through multiple matings. Body size was not a key predictor of male reproductive success, and for females, body condition – but not body length – was the critical fecundity trait. Altogether, a combination of factors suggests that post‐copulatory mechanisms of sexual selection (e.g. sperm competition, cryptic female choice) may play critical roles in this mating system and perhaps that of other snakes. We interpret our findings in the context of sexual conflict – a ubiquitous and potent driver of mating strategy evolution – to propose a scenario for the evolution of female promiscuity that is applicable to many other animal systems where males roam widely to locate females at high costs.

Sexual selection studies often focus on morphological traits that are important only in the later stages of mate acquisition. Comparatively little is known about traits that lead to mate acquisition, such as mate-searching activities. We experimentally manipulated body condition (i.e., the energy reserves) in male puff adders (Bitis arietans) prior to the mating season using supplemental feeding in the field, and used radio-telemetry and DNA paternity analyses to characterize the relationships between male energy reserves, mating activities, and reproductive success. We found that male mobility is a strongly sexually selected trait because males that travelled further in search of females have higher female encounter rates and reproductive success. However, supplemental feeding did not have a significant effect on mating activities or reproductive success, because control snakes compensated by foraging more often during the mating season. The time invested in foraging by control snakes did not come at the costs of decreased mating activities or opportunity compared to fed snakes, because the latter spent the spare time resting. Our experimental field research directly demonstrates the link between male mobility and reproductive success, identifying the ultimate mechanism leading to the evolution of prolonged male mate-searching activities in snakes, and indicates that male puff adders, presumed capital breeders, adjust their breeding tactics according to resource availability.

Foraging modes (ambush vs. active foraging) are often correlated with a suite of morphological, physiological, behavioural and ecological traits known as the "adaptive syndrome" or "syndrome hypothesis." In snakes, an ecological correlate often reported in the literature is that ambush-hunting snakes have a higher relative meal size compared to actively foraging snakes which feed on smaller prey items. This large meal versus small meal feeding hypothesis between ambush and active foragers has become a widely accepted paradigm of snake feeding ecology, despite the fact that no rigorous meta-analysis has been conducted to support this generalization. We conducted a phylogenetically explicit meta-analysis, which included ca. 100 species, to test this paradigm of snake feeding ecology. We gathered data on prey size by inducing regurgitation by palpation in free-ranging snakes and by examining the stomach contents of preserved museum specimens. When we found prey, we recorded both snake and prey mass to estimate relative prey mass (prey mass/snake mass). We also reviewed published studies of snake feeding ecology to gather similar information for other species. Ambush and active foragers did not differ in minimum or average meal size but the maximum meal sizes consumed by ambush-foraging snakes were larger than the maximum meal sizes eaten by active foragers. This results in ambush-foraging snakes consuming a significantly wider range of meal sizes, rather than being large meal specialists compared to active foragers. We argue that ambush foragers evolved to be more opportunistic predators because they encounter prey less frequently compared to active foragers. This hypothesis is further supported by the fact that ambush foragers also exhibited marginally wider diet breadths, consuming a broader range of prey types in comparison with active foragers. Our study challenges aspects of the foraging syndrome as it is currently conceived, and our results have important implications for our understanding of how foraging mode has shaped the behaviour and physiology of ambush-foraging snakes.

Cesar Aguilar, Leandro Alcalde, Phillip Allman, Staci Amburgey, Thomas Anderson, Denis Andrade, Fabien Aubret, Délio Baêta, Betsy Bancroft, Anthony Barley, Christopher Beachy, David Beamer, Daniel Beck, Rayna Bell, Gabriel Blouin-Demers, David Booth, Rafael Bovo, Reuber Brandão, Josephine Braun, Valerie Buxton, Nathan Byer, Michael Caldwell, Carlos Camp, Dario Cardozo, Michael Cardwell, Emerson Castilho-Martins, Santiago Castroviejo-Fischer, Ming-Feng Chuang, Vincent Cobb, Kristina Cohen, Warren Conway, Andrew Cronin, Dane Crossley, Brian Crother, Helio da Silva, Raul Dı́az, Jr., Roberta Damasceno, Juan Daza, Vania Regina De Assis, Andre Luiz de Carvalho, David Delaney, Pedro E. Dias, Colleen Downs, Douglas Eifler, Julian Faivovich, Bryan Falk, Rodrigues da Silva Fernando, Patrick Fitze, Jinzhong Fu, Megan Gall, Ariovaldo Giaretta, Matthew Gifford, Xavier Glaudas, Scott Goetz, Jeronimo Gomes Da Silva Neto, Johana Goyes, Taran Grant, Eli Greenbaum, Lee Grismer, Peng Guo, Jen Hamel, Fabio Hepp, Tom Herman, Grant Hokit, Marinus Hoogmoed, Steven Hromada, Kim Hunter, Margaret Hunter, Elizabeth Jockusch, Gunther Köhler, Ben Karin, David Kizirian, Sean Kuchta, Chi-Yun Kuo, Simon Lailvaux, Norman Lee, Edgar Lehr, Felipe Leite, Erik Lindquist, Ana Longo, Jeffrey Lovich, Kate Marshall, Itamar Martins, Alicia Mathis, Ross McCulloch, Jimmy McGuire, Joseph Mendelson III, Alice Millikin, Thomas Mohrman, Miguel Molina-Borja, Leonardo Moreira, Martha Munoz, Matthew Murphy, Megan Murphy, Rene Murrieta-Galindo, Edward Myers, Melia Nafus, Edward Narayan, Lorin Neuman-Lee, Zaida Ortega, Jhon Jairo Ospina-Sarria, Dustin Owen, Mónica Páez, Theodore Papenfuss, James Parham, Gabriela Parra, Ann Paterson, Joseph Pechmann, Guillem Perez, Bill Peterman, Jennifer Pramuk, Alejandro Rı́os-Franceschi, Michael Reichert, Jeanne Robertson, John Roe, Juliana Roscito, Sean Rovito, Sara Ruane, Samantha Rumschlag, Luis Martin San-Jose Garcia, Pilar Santidrián Tomillo, Pedro Segurado, David Sever, Shane Siers, Lora Smith, John Socha, Carol Spencer, Nancy Staub, Brian Sullivan, Bill Sutton, Mariane Targino, Ryan Taylor, Stanley Trauth, Ines Van Bocxlaer, Fernando Vargas-Salinas, Florencia Vera Candioti, Katyuscia Vieira, Wolfgang Wüster, Hardin Waddle, Theresa Walters, Daniel Warner, Gregory Watkins-Colwell, David Weisrock, Perry Wood, Tristram Wyatt, Luis Zambrano.

Bitis arietans is a widespread and abundant African viper for which minimal genetic resources exist. We screened 88 microsatellite loci published for species within the clades Crotalinae and Viperinae. We identified 11 microsatellite loci which cross-amplified in B. arietans and were polymorphic. We characterized the number of alleles, observed and expected heterozygosities, and probability of identity for each locus by genotyping 87 adults selected haphazardly from a larger sample dataset. These loci provide a resource for researchers within the genus Bitis and are being utilized in a larger study designed to determine paternity of B. arietans litters.

Examination of the gastrointestinal contents of museum specimens is routinely used as a method for assessing diet in a wide variety of reptiles. However, this method might be biased toward detecting prey items that are less digestible and larger in size because these food items are digested more slowly. In this study, we used fixed videography on free-ranging Puff Adders (Bitis arietans) as a comparative, data-collecting technique to assess the accuracy of the traditional method of examination of the gastrointestinal tracts of museum specimens as a measure of diet. The data-collecting method affected our measures of diet: Analyses relying on museum specimens showed a much narrower diet breadth compared to fixed videography, and measures of mean relative prey mass were more than three times larger using museum specimens compared to fixed videography. Our findings demonstrate that data collected through fixed videography and examination of museum specimens provide different perspectives of a snake's diet because of the biases associated with museum specimens. As a result, the use of museum specimens to assess diet should be interpreted cautiously and with knowledge of these biases, as the technique might only reveal certain aspects of a species trophic ecology. In particular, we suggest that the routine use of methods such as examination of museum specimens and palpation of live snakes might have led to a biased interpretation of the feeding ecology of ambush-foraging snakes.

The effect of food availability on the spatial ecology of animals varies within and across study systems because a multitude of factors can affect the spatial activity of organisms. Low-energy specialists, such as ambush-foraging snakes, feed infrequently and can endure long periods without food. Because they have low-energy requirements, one possible tactic for feeding may be to simply ambush for longer periods when prey availability is low, thereby decreasing the potential costs associated with locating new ambush sites. We used radiotelemetry, supplemental feeding, and remote video cameras on free-ranging male puff adders (Bitis arietans) in South Africa to test the hypothesis that food intake affects the foraging ecology of extreme low-energy, ambush foragers and to quantify their natural feeding rates. Supplementally fed puff adders improved their body condition, spent less time foraging, and decreased distance traveled compared to control snakes. However, movement frequency and home range size did not differ between the two groups. These findings indicate that control snakes traveled farther within similar-sized home ranges compared to fed snakes and did so at no survival cost. Further, naturally foraging puff adders successfully caught a prey of small size once every 10 days on average. Hence, despite their "sit-and-wait" foraging strategy and their low-energy intake/requirements, underfed puff adders travel widely to presumably find appropriate ambush sites that maximize prey capture. Our research provides the first strong evidence that the spatial activity of a terrestrial vertebrate species with extremely low energetic demands is significantly affected by food intake.Significance statementBecause animals travel their home range partly to forage, their space use can be affected by the amount of food available in nature. We show that, despite a low-energy lifestyle, the movement level of an ambush-foraging snake that feed infrequently is linked to the amount of food they eat. Underfed snakes traveled greater distances in search of prey, within similar-sized home ranges, compared to well-fed snakes, and they did so at no survival cost. Hence, our research adds to our understanding of the effect of food on the spatial ecology of animals, by providing conclusive evidence that the spatial response of an organism with extremely low-energy demands can be affected by food.

The dangerous prey hypothesis predicts that when predators can discriminate between harmless and dangerous prey, they should alter their predatory behavior according to the risk. Venomous snakes, which rely on an envenomating strike to kill prey, often feed on potentially dangerous prey such as rodents, and have the choice between two alternative strategies following a bite: they either hold onto prey until it is incapacitated, or release it immediately, relying on scent trailing to find the bitten prey. In this study, we combined observational and experimental data collected in the field in South Africa to test the hypothesis that prey type and size affected the predatory strategy of a venomous snake, the puff adder ( Bitis arietans; Viperidae). Relative prey size, but not prey type, affected the snake's strategy: puff adders typically struck and held prey of small size (e.g., toads, small adult mice and shrews), but often struck and released larger prey (e.g., large adult mice and rats), presumably because retaliatory bites from the latter ones are more dangerous. Hence, puff adders discriminated according to prey size and adjusted their predatory strategy consequently. Contrary to the common belief that viperid snakes typically strike and release prey, our findings agree with empirical evidence found in the literature, that is, puff adders generally alter their predatory tactics based on prey size. Although a few laboratory studies have examined the theme of the present paper in other venomous snakes, our research was conducted in a natural setting and thus provides a better understanding of the factors used by predators to choose between alternative hunting strategies.

The society would like to thank the following individuals who served as outside reviewers of submitted manuscripts during 2014 and 2015. The caliber and timeliness of reviews are principal determinants of the quality of the Journal, and we deeply appreciate the expertise and assistance provided by these colleagues. We also wish to express our special gratitude to the Editorial Board (listed on the inside front cover) for their outstanding cooperation and assistance. * indicates a colleague who completed more than 1 review.

Aggressive mimic species use signals typically resembling an attractive or harmless model to deceive other organisms in order to increase foraging success. With the exception of a few brood parasitic birds that combine two signals, most known cases of aggressive mimicry involve only a single signal. Here, we used fixed videography, a technique which consisted in setting up continuously recording videocameras focused on ambushing animals, to describe- for the first time-the use of two clearly distinct aggressive visual mimicry signals in the same organism, the puff adder (Bitis arietans). Our observational data collected in South Africa revealed that puff adders extended their tongues (lingual luring) and waived their tails (caudal luring), presumably mimicking an invertebrate model, in order to lure prey within striking range. Lingual luring occurred only in the presence of amphibian prey, indicating discrimination between prey types. Our study reveals the diverse predatory strategies and complex decision-making process used by 'sit-and-wait' predators, such as ambush-foraging snakes, to catch prey, and indicates that snakes may have higher cognitive abilities than those usually afforded to them.Significance statementPredators exhibit various strategies to increase rates of prey capture. One strategy involves the use of luring behaviours, which are signals designed to attract prey within striking range. Using remote videocameras focused on ambush-hunting puff adders (Bitis arietans) in the field, we report-for the first time-the use of two clearly distinct luring behaviours in the same organism: puff adders extended their tongues and waived their tails, which presumably resemble invertebrate prey, to draw prey within striking range. Tongue-luring behaviour was solely used in the presence of amphibian prey, which indicates that puff adders distinguished between prey types. Our research underscores that the predatory decisions made by ambush-foraging snakes are diverse and context-dependent and further demonstrates that these predators possess higher cognitive abilities than first expected.

Ambush foragers use a hunting strategy that places them at risk of predation by both visual and olfaction-oriented predators. Resulting selective pressures have driven the evolution of impressive visual crypsis in many ambushing species, and may have led to the development of chemical crypsis. However, unlike for visual crypsis, few studies have attempted to demonstrate chemical crypsis. Field observations of puff adders (Bitis arietans) going undetected by several scent-orientated predator and prey species led us to investigate chemical crypsis in this ambushing species. We trained dogs (Canis familiaris) and meerkats (Suricata suricatta) to test whether a canid and a herpestid predator could detect B. arietans using olfaction. We also tested for chemical crypsis in five species of active foraging snakes, predicted to be easily detectable. Dogs and meerkats unambiguously indicated active foraging species, but failed to correctly indicate puff adder, confirming that B. arietans employs chemical crypsis. This is the first demonstration of chemical crypsis anti-predatory behaviour, though the phenomenon may be widespread among ambushers, especially those that experience high mortality rates owing to predation. Our study provides additional evidence for the existence of an ongoing chemically mediated arms race between predator and prey species.

Fifty-six speckled rattlesnakes, Crotalus mitchellii, from western North America were examined for helminths. One species of Cestoda (tetrathyridia of Mesocestoides sp.) and 5 species of Nematoda (gravid adults of Abbreviata terrapenis, Physaloptera abjecta, Thubunaea cnemidophorus, and Travassoascaris araujoi and larvae of Physocephalus sp.) were found. Travassoascaris araujoi had the highest prevalence and greatest mean intensity of helminths infecting C. mitchellii. Three new host records for C. mitchelhi are reported. As has been reported for other North American rattlesnakes, C. mitchellii is parasitized by "generalist" helminths.

Seasonal aphagia (a lack of feeding) can occur if foraging and reproduction occasionally result in conflicting demands on an individual, such that one activity takes precedence over the other. We tested the hypothesis that female and male Crotalus cerastes (Sidewinders) exhibit seasonal aphagia during the reproductive season. We examined the stomach contents of preserved specimens to assess variation in the feeding rates of C. cerastes. Non-reproductive females fed during the early and late stages of the active season, but reproductive females only ate during the first half of the active season. Female Sidewinders fed throughout the early vitellogenic phases of the reproductive cycle, but exhibited a tendency to reduce or cease feeding during the later stages of the cycle (gestation). Prey consumption during early reproductive stages can provide valuable energetic resources for sustaining a female's subsequent breeding activities. However, the physical burden of offspring mass and the concomitant decrease in locomotor efficiency can reduce a female's foraging efficiency in the later phases of the reproductive cycle. Male C. cerastes displayed a trend to feed more frequently during the reproductive season, perhaps because enhancing their energy reserves allows males to travel longer distances and maximize encounter rates with females. The discovery of this intersexual variation in feeding patterns of C. cerastes underscores the importance of descriptive ecological studies to elucidate distinct patterns of life history evolution.