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An adult male Ameiva ameiva courts a dead conspecific female (MZUFV 766). The male mounts on the back of the female (A, B, C), and later makes series of movements with hind limbs, trying to pair his cloaca with the female’s (D, E, F). Photos and video frames by E. T. da Silva.
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Herein, we report necrophilia (Davian behaviour) in the lizard Ameiva ameiva in Brazilian Atlantic Forest Domain. A male A. ameiva was found during a sunny day courting and trying to copulate with a road-killed female. The presence of developed ovarian follicles confirmed that the female was in breeding condition. The female probably died while mak...
Context in source publication
Context 1
... dead adult female (probably killed after being run over by a vehicle), on the centre of the road. The male pressed his gular region against her back, rubbed it repeatedly with lateral movements of his head and flicked tongue several times. Then, he made a series of movements with his hind limbs, trying to oppose his cloaca with the female's ( Fig. 1), but apparently not everting his left or right ...
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Here we report a dramatic body colour change of a male anole lizard during copulation.
Citations
... activity period (Vitt et al., 2008). Its reproductive cycle can vary according to the geographical distribution of the species, tending to be extended in areas where the rainy season is less defined and seasonal in areas where the rainy season is more defined (Colli, 1991;Vitt and Colli, 1994;Costa et al., 2010). Despite this, the mating season of the species seems to occur markedly during the spring and summer (Ramalho et al., 2021). ...
... On 12 March 2009, during the summer, in an urban area at the Brazilian Atlantic Forest domain, Costa et al. (2010) recorded a male Ameiva ameiva repeatedly attempting to copulate with a conspecific female that appeared to be deceased, presumably due to a vehicular collision. These observations also included confrontations between the initial male and a rival male who subsequently approached the female. ...
... These observations also included confrontations between the initial male and a rival male who subsequently approached the female. The present study aims to revisit the findings reported by Costa et al. (2010) to address several lingering questions related to the observed events: 1) Were the mating attempts by the initial male indeed successful? 2) Did the deceased female carry "fertilised eggs" and "developing follicles"? 3) Could the reproductive status of the deceased female be linked to the production and dispersal of pheromones that attracted the male and triggered mating behaviour? Answering these questions is important because, even though this behaviour has been reported several times (Vitt, 2003;Costa et al., 2010;Sazima, 2015;Valdez-Villavicencio and Peralta-García, 2020), these generally concern only the in-situ observational records. ...
... Necrocoitus has been documented in a wide array of species, though it is not common in any one species. Most observed instances of necrocoitus span reptiles, amphibians, and birds (e.g., How & Bull, 1998;Costa et al., 2010;Izzo et al., 2012;Tomita & Iwami, 2016;Swift & Marzluff, 2018;Ashaharraza et al., 2020). Dolphins are highly intelligent mammals with complex social systems (Marino, 2004;Connor, 2007;Wells, 2013) and are, therefore, unlikely to have the same motivating factors behind instances of necrocoitus as other taxa. ...
... Since the male dolphins in the cases presented here were presumably aware the females were dead, it is unlikely that they were reacting to perimortem pheromone expression, which has been posited as an explanation for necrocoitus in several taxa (Costa et al., 2010;Siqueira et al., 2015;Ashaharraza et al., 2020;Colombo & Mori, 2020), including Florida manatees, who occasionally pursue females to the point of exertional myopathy and death (Bills et al., 2013;Walsh & de Wit, 2015;Reynolds et al., 2018). This was investigated through ovary examination. ...
... Courtship and copulation in lizards involve a series of ritualised behaviours (Vitt, 1983;Costa et al., 2010;Gogliath et al., 2010;Ribeiro et al., 2011). Examples of these behaviours in teiid lizards include chase, cloacal rubbing and head bobbing (Carpenter, 1960(Carpenter, , 1962Quesnel, 1978;Costa et al., 2013;Sales & Freire, 2021). ...
... It is continuous or extended in the Amazon forest, Caatinga, and the restingas of the Atlantic Forest but is more seasonal in the Cerrado and Amazonian savannas (Vitt & Colli, 1994;Rocha, 2008). In summer in the Atlantic Forest, Costa et al. (2010) described courtship behaviour and attempted copulation between an adult male and a dead conspecific female that had six oviductal eggs. However, the size of these eggs resembles that of enlarged vitellogenic follicles (R.A. Ramalho, unpublished data) suggesting that the dead female was in late vitellogenesis. ...
The courtship and copulation behaviours of the lizard Ameiva ameiva is described from field observations made at various locations in Brazil. In males, the main behaviours observed during one observation of courtship were head bobbing, circling and walking over the females, rubbing his body against the female, mounting, and dismounting. Females generally remain passive throughout courtship. The reproductive behaviour of A. ameiva resembles that of other teiids, however males exhibit some behavioural peculiarities, such as circling the female to restrict her movements, no cloacal rubbing against the ground, and no biting during copulation.
... Necrophilia, also known as necrogamy (Bettaso et al. 2008), thanatophilia (Patel et al. 2016), and Davian behavior (Dickerman 1960), is a form of reproductive behavior in which a living specimen (usually a male) attempts to copulate with a dead conspecific (usually a female). It has been reported in all major extant groups of tetrapods (Caldeira-Costa et al. 2010). Among anurans it has been reported in at least 37 species from six families: Ascaphidae (one species), Bombinatoridae (1), Bufonidae (15), Hylidae (8), Leptodactylidae (1), and Ranidae (11). ...
... Necrophiliac behaviour, also known as Davian behaviour, thanatophilia and necrogamy, is a poorly understood behaviour in reproductive ecology involving sexual interactions between living males and dead females or males [1][2][3][4]. Despite the associated energetic and time-consuming costs of this behaviour [5], several observations of amphibians in amplexus with dead conspecifics have been registered (Table 1a). ...
... Necrophilia has been long considered as a maladaptive behaviour because individuals may lose an opportunity to reproducing successfully [16]. Further, necrophilia may result in an increased predation risk due to longer time spent in the water (breeding sites) [5,17], increased road kills when males engage in amplexus with run over dead females [1,4,18], and may facilitate the propagation of infections [15,19]. However, some authors consider that necrophilia may be functional in some cases. ...
Necrophilia in amphibians is a poorly known behaviour despite its potential as a beneficial adaptation for improving reproductive success. Here, we describe the observation of a multiple amplexus involving necrophilia in the recently described Tsachila snouted treefrog, Scinax tsachila (Anura: Hylidae). We further provide an extensive review of published necrophilia in amphibians. At least 33 species of amphibians, mostly anurans, have shown a necrophiliac behaviour, with only one case of necrophilia in a caudate. Necrophilia has long been considered a maladaptive behaviour, since reproduction is usually not viable and is also associated with increased risk of death. However, necrophiliac behaviour has recently been proposed as an adaptive behaviour for some species because it may result in viable offspring.
... Necrozoophilia, also known as Davian behaviour or thanatophilia, is a form of reproductive animal behaviour in which the male of a species attempts copulation with a dead conspecific female. It has been reported in all major groups of tetrapods (Dickerman, 1960;Lehner, 1988;Sinovas, 2009;Costa et al., 2010), Anurans (Meshaka, 1996;Bettasoet al., 2008;Sinovas, 2009;Mollov et al., 2010;Brito et al., 2012;Izzo et al. 2012;Bedoya et al., 2014) and Lizards (Sharred et al., 1995;How and Bull, 1998;Vitt, 2003;Fallahpour, 2005;Brinker and Bucklin, 2006). Relative rarely, the phenomenon has also been recorded in snakes (Amaral, 1932;Siqueira et al., 2015). ...
The active reproductive cycle of female snakes may promote necrophilia, as chemical cues, trails and pheromones are still released after death, permitting courtship and copulation by young reproductive males. In fact, Fowlea piscator is known to lay eggs between December to March and the present incident occurred during its breeding season, thus supporting this hypothesis.
Natural history studies on central Indian snakes are still scarce and required imperative documentation. The Davian behaviour in south Asian snakes was never documented and is here reported for the first time from India and from Thailand.
... In behavioural ecology, "Davian behaviour" is defined as the sexual attraction and copulation act involving a living animal individual (most often a male) and a dead (female) conspecific (Dickerman 1960). Davian behaviour has been reported as a "behavioural mistake", rarely occurring in animal populations, possibly concerning young reproductive males, who may not access partners for their hierarchical or social position (Meshaka 1996, Costa et al. 2010, Russell et al. 2012. Amongst vertebrates, this behaviour is mostly recorded in heterothermic species, i.e. reptiles and amphibians, which show explosive reproductive periods (e.g. ...
We reported the first record of Davian behaviour (necrophilia) in the Eurasian badger Meles meles (L., 1758) in northern Italy. A male badger was observed in a camera-trap survey courting and trying to copulate with a probably road-killed female, in February. The dead female was a sexually mature, adult individual; the male was probably a young mature individual. Social behaviour of this carnivore may have evolved to guarantee the access to females only to the dominant male. Usually, female badgers passively receive mating by excited males. This behaviour may have enticed the young male to start courtship and copulation with the road-killed female.
... Sexual arousal in response to dead conspecifics has been documented in bottle nosed dolphins [4] and humpback whales (Magaptera novaeangliae; [34]). Mating attempts with dead conspecifics have been observed in Richardson's ground squirrel (Citellus richardsoni), mallards (Anas platyrhynchos), sand martins (Riparia riparia) cururu toads (Rhinella steuvax) and great ameivas (Ameiva ameiva; [35][36][37][38][39]). The copulation posture typical of dead birds has been proposed as the releasing factor for such inappropriate attempts to mate, particularly among monomorphic birds [37]. ...
Observations of some mammals and birds touching their dead provoke questions about the motivation and adaptive value of this potentially risky behaviour. Here, we use controlled experiments to determine if tactile interactions are characteristic of wild American crow responses to dead crows, and what the prevalence and nature of tactile interactions suggests about their motivations. In Experiment 1, we test if food or information acquisition motivates contact by presenting crows with taxidermy-prepared dead crows, and two species crows are known to scavenge: dead pigeons and dead squirrels. In Experiment 2, we test if territoriality motivates tactile interactions by presenting crows with taxidermy crows prepared to look either dead or upright and life-like. In Experiment 1, we find that crows are significantly less likely to make contact but more likely to alarm call and recruit other birds in response to dead crows than to dead pigeons and squirrels. In addition, we find that aggressive and sexual encounters with dead crows are seasonally biased. These findings are inconsistent with feeding or information acquisition-based motivation. In Experiment 2, we find that crows rarely dive-bomb and more often alarm call and recruit other crows to dead than to life-like crows, behaviours inconsistent with responses given to live intruders. Consistent with a danger response hypothesis, our results show that alarm calling and neighbour recruitment occur more frequently in response to dead crows than other stimuli, and that touching dead crows is atypical. Occasional contacts, which take a variety of aggressive and sexual forms, may result from an inability to mediate conflicting stimuli.
This article is part of the theme issue ‘Evolutionary thanatology: impacts of the dead on the living in humans and other animals’.
... With respect to reproductive behaviour, teiid lizards have proven to be difficult to study in the wild with respect to social interactions because of their active mode of foraging, which tends to lead to enlarged home ranges (Censky 1995b), and strong wariness, which is linked to their foraging mode and predator escape strategy (Vitt & Price 1982). Thus, studies reporting social interactions in teiids are often based on incidental observations (Vitt 1983, Costa et al. 2010, 2013, Ribeiro et al. 2011, and the few studies that investigated social interactions quantitatively were conducted in insular populations (Censky 1995b, 1997, Baird et al. 2003, Zaldívar-Rae & Drummond 2007, Ancona et al. 2010, where the lizards often occur at elevated densities and so facilitate observations by investigators. For mainland species, especially Ameivula, little is known about courtship and mating behaviour. ...
This study provides ecological and behavioural data on the reproduction of the whiptail lizard Ameivula ocellifera in the Caatinga biome, northeastern Brazil. Our fieldwork consisted of monthly trips for three consecutive days, from January 2009 through June 2010. Incidental observations of reproductive behaviour were recorded in 2012, during a study on foraging behaviour. We found sexual dimorphism in maximum body size and head dimensions, with higher values in males. Clutch size averaged 2.41 +/- 0.78 (range: 1-4) and was not correlated with female body size. Egg volume averaged 589.26 +/- 77.27 mm(3), egg mass averaged 0.594 +/- 0.126 g, and relative clutch mass averaged 0.156 +/- 0.053. Twelve of the 29 females in reproductive condition contained vitellogenic follicles and oviductal eggs or corpora lutea simultaneously. We registered reproductive females both in the rainy and dry seasons, and the proportion of reproductive females was significantly correlated with monthly rainfall, but not with air temperature. Average testis volume did not differ annually, and there were no significant relationships of testis volume with rainfall and air temperature. We registered a set of behavioural expressions of A. ocellifera related to courtship and mating; cloacal rubbing is among the most evident behavioural expressions involved in courtship, and males accompanying receptive females occurs before and after copulation. We conclude that A. ocellifera has a prolonged reproductive period in the Caatinga, is apparently continuous, but exhibits seasonal variations in reproductive activity. Rainfall unpredictability in the study area may be the major factor for the prolonged reproductive cycle. Most females produce series of clutches of two eggs each. The reproductive behaviour of A. ocellifera is very similar to North American whiptails, most likely reflecting a common phylogenetic origin among this lineage of lizards.
... N ecrophilia, also known as thanatophilia or Davian behavior, is a form of reproductive behavior that involves attempted copulation with dead conspecifics; it has been reported in several species of all major groups of tetrapods (Dickerman 1960;Lehner 1988;Sinovas 2009;Costa et al. 2010). Among anurans, Davian behavior has been reported in a few species from North and South America and Europe (Bedoya et al. 2014;Bettaso et al. 2008;Brito et al. 2012;Izzo et al. 2012;Meshaka 1996;Mollov et al. 2010;Sinovas 2009). ...
