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The Corpse Bride: A case of Davian behaviour in the Green Ameiva (Ameiva ameiva) in southeastern Brazil


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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 making a chemical trail to attract reproductive males. Apparently the male’s behaviour was influenced by the high temperature of the female’s body that was warmed up by the heat of the sun. Although Davian behaviour is not expected to occur frequently, a high number of dead reproductive females in Brazilian roads could result in a high frequency of necrophilia in A. ameiva.
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Necrophilia has been reported in several species of
all major groups of tetrapods. There are observations of
this kind of behaviour in mammals (Dickerman, 1960;
Bagemihl, 1999), birds (Lehner, 1988; Moeliker, 2001;
Bagemihl, 1999), amphibians (Meshaka-Jr., 1996;
Bettaso, Haggarty and Russel, 2008; Sinovas, 2009)
and reptiles (Amaral, 1932; Belluomini and Hoge,
1957/1958; Lambiris, 1966; Sharrad, King and Cairney,
1995; How and Bull, 1998; Vitt, 2003; Fallahpour,
2005; Brinker and Bucklin, 2006). The name Davian
behaviour was rst used by Dickerman (1960) when he
observed necrophilia in ground squirrels Citellus (now
Spermophilus). The term is a reference to a limerick
about an old necrophiliac miner named Dave.
In the present work we describe courtship behaviour of
an adult male A. ameiva with a dead conspecic female
during eldwork in southeastern Brazil.
The Green Ameiva, Ameiva ameiva (Linnaeus,
1758) has one of the widest distributions among New
World tropical lizards, occurring in most of tropical
and subtropical South America on east of the Andes,
extending north to Panama (Vitt et al., 2008). This
heliothermic medium-sized teiid (snout-vent length
40-190 mm) inhabits a great number of ecosystems,
spanning from semi-arid regions to wet lowland forests,
and even habitats that are disturbed by human activity
(Vitt and Colli, 1994; Sartorius, Vitt and Colli, 1999).
Ameiva ameiva is sexually dimorphic, with adult males
being larger than females (Colli, 1991; Vitt and Colli,
1994; Rocha, 2008). Reproductive period varies along
a broad geographical range, tending to be continuous in
areas where rainfall is abundant throughout the year or
highly unpredictable, and cyclical in areas with a highly
seasonal climate (Colli, 1991; Vitt and Colli, 1994).
However, continuous reproduction has been reported in
Herpetology Notes, volume 3: 079-083 (2010) (published online on 23 March 2010)
The Corpse Bride: a case of Davian Behaviour in the Green Ameiva
(Ameiva ameiva) in southeastern Brazil
Henrique Caldeira Costa*1,2, Emanuel Teixeira da Silva1,2, Pollyanna Silva Campos3,
Marina Paula da Cunha Oliveira1, André Valle Nunes1 and Patrícia da Silva Santos4.
1 Museu de Zoologia João Moojen, Vila Gianetti 32, Univer-
sidade Federal de Viçosa, Viçosa, MG CEP: 36570-000,
Brazil; e-mail:
2 Programa de Pós-graduação em Biologia Animal, Departa-
mento de Biologia Animal, Universidade Federal de Viçosa,
Viçosa, MG, Brazil;
3 Museu de História Natural Eduardo Marcelino Veado, Centro
Universitário de Caratinga – UNEC, Campus II, Rua Niteroi,
s/nº, Bairro das Graças, Caratinga, MG CEP 35300-000;
4 Pós-graduação em Ecologia Conservação e Manejo de Vida
Silvestre, Universidade Federal de Minas Gerais, Laboratório
de Herpetologia, sala 242 Bloco E2, Av. Antônio Carlos
6627, Pampulha, Belo Horizonte, MG CEP 31270-901,
* corresponding author
Abstract. 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 conrmed that the female was in breeding condition. The female probably died while making a chemical trail
to attract reproductive males. Apparently the male’s behaviour was inuenced by the high temperature of the female’s body that
was warmed up by the heat of the sun. Although Davian behaviour is not expected to occur frequently, a high number of dead
reproductive females in Brazilian roads could result in a high frequency of necrophilia in A. ameiva.
Keywords. Squamata, Teiidae, courtship, necrophilia, reproduction.
Henrique Caldeira Costa et al.
habitats with marked seasonality (Rocha, 2008).
Despite the availability of biological data concerning its
reproduction, information on courtship and reproductive
behaviour of Ameiva ameiva remains scarce. To the best
of our knowledge, the only observations on A. ameiva
courtship in the wild were those presented by Manata
and Nascimento (2005) in Serra do Cipó National Park,
southeastern Brazil, and by Vitt (2003) at Amazon of
northern Brazil.
Materials and methods
Observations took place during an environmental impact as-
sessment on 12 March 2009, on a dirt road at the urban area of
the district of Tabajara, municipality of Inhapim, Atlantic Forest
of the state of Minas Gerais, southeastern Brazil (19.586500º S,
41.762614° W). There was herbaceous vegetation on one side of
the road, near a pen, and a house on the other side. Observations
were written down on a notebook, and some photos and videos
were taken using a digital camera (Sony DSC H 50).
At 10:50 a.m. (air temperature ca. 33 ºC), we saw at a 5-
6 m distance, an adult male of Ameiva ameiva, mounted
on the back of a conspecifc 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 icked 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 hemipenis.
At 10:59 a.m. a second male, slightly smaller than
the rst one, came from the vegetation and began to
approach the female, being promptly chased away
by the rst male. Both males ran to the bushes close
to the road’s edge. At this time, the female’s tail lifted
up, and we checked to see if she was still alive (Fig.
2). After conrming it was dead, the female’s body was
returned to its former position. Soon after, the rst male
returned, circled around the female, and rubbed his
Figure 1. An adult male Ameiva ameiva courts a dead conspecic 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.
Necrophilia in the Green Ameiva 81
Figure 2. A second male Ameiva ameiva, slightly smaller than the rst one, came from the vegetation and begins to get closer to
the female, being promptly frighten by the rst male (A-F). Both males ran to the bushes close to the edge of the road (G). At this
time, the female’s tail lifted up (H). Photo and video frames by E. T. da Silva.
head repeatedly, before attempting another courtship
engagement. The second male returned three more
times, only to be chased again by the rst one. Later,
the second male stayed around the area and crossed the
A total of 11 charges of the rst male over the female
were observed, within 20 minutes since the beginning
of the observations. The last charge was at 11:09 a.m.,
and during the coupling trial the male went away from
the dead female twice, to short distances, still remaining
in the proximity of her body, without entering the
vegetation. After that, he abandoned the female’s body.
Eight minutes after the male left the scene, the female’s
body began to present signals of dehydratation. Her tail
was erect and head and front limbs were contracting. We
took the lizard from the road and collected it at 11:17
a.m. The two males were observed in close proximity
for ve more minutes, apparently foraging.
We interrupted the male’s behaviour ve times. In three
of them, we moved the female’s body away from the road
due to the passing of vehicles (returning it to the same
place soon after). Another time was for photographic
record, and the other was during the spontaneous lifting
of the female’s tail. There were also two voluntary
departures of the rst male besides the ones reported,
as a response to the second male’s approaches. In all
charges of the rst male over the female there were
coupling trials or courtship behaviour.
The dead female was xed in 10% formalin and
dissected, which revealed the presence of six apparently
fertilized eggs (14.1 x 12 mm; 14.45 x 12.35 mm; 14 x
13 mm; 14.65 x 12.5 mm; 15 x 12.2 mm; 14.7 x 12.75
mm) and several follicles in development (18 in the
right and 14 in the left ovary).
Vitt (2003) was the rst to report necrophilia in
Ameiva ameiva, at Amazon biome in northern Brazil.
He shot a female that was being courted by a large male,
who instantly ran off. Soon after, the male returned,
tongue icked the area, located the female and tried
to mate with her, when he was shot. The same process
was done later with a second smaller male (Vitt, 2003).
Although the report of Vitt (2003) is quite similar to the
one presented here, the fact that he killed both males
soon after they tried to mate with the dead female did
not allow him make some behavioural observations (i.e.
the number and duration of coupling attempts or the
interactions between the larger and the smaller male).
The presence of ovarian follicles in development
shows that the dead female found by us was in breeding
season. Unfortunately, we do not know whether the rst
male was already courting the female when she was run
over, or if he rst found her only after she was killed. If
he was courting the female when she was killed (and he
luckily escaped), he just did not notice that his partner
was dead, continued the courtship and coupling trials,
like the case reported by Vitt (2003).
In both sexes of Ameiva ameiva, the ventral skin of
the thighs shows a single row of 16-23 femoral pores,
each one opening in the centre of a modied scale,
resembling a rosette (Imparato et al., 2007). As in other
lizard species, these pores are connected to internal
glands that produce a solid secretion containing non-
volatile chemical cues that play a relevant role in social
behaviour (Pianka and Vitt, 2003; Imparato et al., 2007).
Therefore, the female was probably secreting chemical
cues to attract breeding males to copulate. In A. ameiva
this method of signal dispersion is intimately dependent
on the locomotion, where the animal left a trail of
chemical signals on the substrate (Imparato et al., 2007).
Thus, the female could have been killed while engaged
in this behaviour.
The female’s chemical trail probably attracted both
male’s attention. The explanation for the males did
not know the female was dead might stand in the fact
that Ameiva ameiva is heliothermic, with relatively
high active body temperatures. Vitt and Colli (1994),
studying eight populations of A. ameiva in four Brazilian
biomes found that these lizards are active with body
temperatures from 26.4 to 42.2. ºC (mostly from 36 to
40 ºC). Observations reported here occurred during a
hot day, when the air temperature was at 33 ºC. This fact
may allow the body temperature of the dead female to
remain elevated, as she was directly exposed to sunlight,
in the centre of the dirt road, and this condition may
have confused the males.
If we are correct, special conditions may favour
necrophilia in Ameiva ameiva as a “behavioural
mistake”. In fact, this kind of mistake appears to
occur in several reports of animal necrophilia, when a
reproductive male tries to mate with a stationary and
seemingly “receptive” female (Lambiris, 1966; Lehner,
1988; Sharrad, King and Cairney, 1995; How and
Bull, 1998; Vitt, 2003; Fallahpour, 2005; Brinker and
Bucklin, 2006). In some cases, necrophilia can also be
just a result of a coupling trial by a male that usually
do not access partners carefully, a common behaviour
in some anurans (Meshaka-Jr., 1996; Bettaso, Haggarty
and Russel, 2008; Sinovas, 2009).
Henrique Caldeira Costa et al.
It is important to note that a high number of road killed
reproductive females of Ameiva ameiva possibly occur
along some Brazilian highways, especially in sunny
days and could even result in a high frequency of Davian
behaviour in this species, as reported for some explosive-
breeding anurans in United States (Meshaka-Jr., 1996).
However, the benets of being the rst to encounter a
female probably outweigh the costs of the mistakes that
can happen sometimes, like trying to couple with a dead
partner (Sinovas, 2009). It is possible that the impact of
Davian behaviour on the evolution of reproduction is
nonexistent (Sharrad, King and Cairney, 1995).
The female A. ameiva (135 mm. snout-vent length) is
deposited in the lizard collection of Museu de Zoologia
João Moojen, Universidade Federal de Viçosa, in
Viçosa, Minas Gerais, Brazil, under the label MZUFV
Acknowledgments. We are grateful to Limiar Engenharia
Ambiental for nancial support and Instituto Brasileiro do
Meio Ambiente e dos Recursos Naturais Renováveis (IBAMA)
for collection permits (#123/2009 NUFAS/MG; process
#02015.014980/2008-50) to ETS, PSC, MPCO, AVN and PSS;
Prof. Jorge Dergam for suggestions and English revision on an
early version of the manuscript; Prof. Izabel Maldonado for
identication of eggs and follicles; Carla S. Cassini, Kamelia
Algiers, Ligia Pizzatto and Walter E. Meshaka Jr. provided
essential bibliography. Prof. Eric R. Pianka suggested valuable
references and critically reviewed a rst draft of this paper. An
anonymous referee also made valuable suggestions on the nal
version of the text.
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Necrophilia in the Green Ameiva
... 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. ...
Full-text available
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.
... 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. ...
Full-text available
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.
... 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). ...
... 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). ...
Full-text available
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]. ...
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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. ...
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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.
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The genus Ameiva Meyer 1795 comprises 23 species of which 14 are found in Central and South America and 18 occur in the West Indies. These lizards occupy diverse habitats (e.g., grasslands, tropical forests, sandy beaches) but most species appear to prefer open areas. They are ground-dwellers and active diurnal foragers. Cuba harbors only one species, Ameiva auberi. However, 40 subspecies are distributed widely across the main island, adjacent cays, and on into the Bahamas. Reproductive behavior has been documanted in some species in the family Teiidae, but not for A. auberi, about which only one published account reported the underground deposition of a single egg. Herein, we describe for the first time the reproductive behavior (except ovipositioning) of A. auberi ustulata in natural habitat in the Ecological Reserve Siboney-Jutici (eastern Cuba) on 22-25 July 2009. Between 1200 and 1600 h, we observed six mating pairs directly or while using monocular Nikon Fieldscopes. We describe three sequential stages of reproductive behaviior: (1) Pursuit, (2) prematiing and mating, and (3) excavation, with a total duration of 64.8+-17.6 min (46-92 min).
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Necrophilia in Holbrookia maculata.
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The reproductive ecology of the teiid lizard Ameiva ameiva was investigated in Cerrado areas of Distrito Federal, Brazil. Reproductive activity was strongly correlated with seasonal patterns of rainfall, being curtailed or reduced during the dry season. Comparisons with other populations indicated that life-history traits of A. ameiva vary along its broad geographical range. Populations in Cerrado produce larger clutches of smaller eggs than in Caatinga of northeast Brazil. Reproduction is continuous in areas where rainfall is abundant all year (Amazonian rain forest) or highly unpredictable (Caatinga), and cyclical in areas of highly seasonal climate (Cerrado and Amazon Savanna). It is concluded that, at lower taxonomic levels, adaptation to the local environment can be a major determinant of life-history patterns of tropical reptiles.
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In this study 57 specimens of the lizard Ameiva ameiva (Linnaeus, 1758) collected in the restinga at Barra de Maricá, in the state of Rio de Janeiro, southeastern Brazil, were analyzed to investigate size relations and reproduction (in females) and sexual dimorphism of this population. We answered the following questions: 1) what is the minimum reproductive body size in females? 2) what is the average clutch size and 3) how is clutch size related to body size? 4) Are body and head sizes sexually dimorphic? Mean clutch size was 6.7 ± 2.1 eggs and was positively correlated with female body size. Sexual dimorphism favoring males was found: adult mean snout-vent length was great in males (124.2 ± 17.8 mm) than females (96.5 ± 23.1 mm SVL), and males were larger with respect to head width and length, and body mass. Thus, despite the marked seasonality at Barra de Maricá, A. ameiva has an extended reproductive period. Also, intrasexual selection may have acted on females to produce larger clutches, and on males, favoring larger males.
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The large-bodied teiid lizard Ameiva ameiva was studied at eight different sites in four major South American habitats of Brazil: caatinga, cerrado, Amazonian rain forest, and Amazonian savanna. We found striking similarity in ecological attributes of this lizard among very different habitats. Activity is concentrated in late morning and early afternoon; active body temperatures average 37.9 ± 0.09 °C and vary little among sites or throughout the day; the diet consists of a variety of vertebrates and invertebrates but is dominated by grasshoppers, roaches, beetles, spiders, and insect larvae; and niche breadths for prey are similar among study sites but the actual composition of the diets varies. There is minimal morphological variation among sites (mostly size); the most striking morphological variation is between the sexes. Males reach larger body sizes and have relatively larger heads than females. Juveniles have relatively larger heads than would be predicted on the basis of body size alone. Sexual selection may explain the sexual differences in head size of adults, whereas the relatively large heads of juveniles may be associated with food competition with sympatric teiid lizards. Clutch size varies from 1 to 11 eggs, is related to female body size (snout–vent length), and varied among study sites. Similar variation among sites occurs in egg size but not in relative clutch mass. An interesting positive relationship was found between body size and relative clutch mass. In a population from the state of Rondônia egg dry mass was correlated with female size, indicating that individual offspring size is, to some extent, a consequence of female size. The reproductive season is extended for all populations and it appears that predictability of rainfall may regulate the season length. Reasons for the apparent success of A. ameiva in a diversity of habitats on a large geographic scale include its large body size, foraging mode, and preferred microhabitat (ecotones and disturbed areas).
We studied the effects of natural and anthropogenic habitat disturbances on environmental temperatures and their consequent effects on thermoregulation and habitat use of Ameiva ameiva in a complex habitat matrix of primary tropical forest and several types of disturbed forest in Amazonian Brazil. Data on Ameiva ameiva from other regions in Brazil with habitats that have little canopy coverage are compared with data from rain forest sites to determine if activity of rain forest Ameiva is temporally or spatially limited by the thermal opportunities available in shaded environments. Ameiva ameiva preferentially used disturbed habitats in rain forest regions. These sites had significantly higher environmental temperatures than did surrounding undisturbed rain forest. Environmental temperature distributions indicate that the closed canopy rain forest is a thermally marginal habitat for Ameiva ameiva and that high temperatures resulting from forest clearing are likely to enable Ameiva ameiva to increase foraging activity in adjacent forest edges above what is possible in the continuous interior forest. Ameiva ameiva from rain forest, cerrado and savanna regions of Brazil had significantly lower body temperatures than Ameiva from caatinga, an open habitat type with little canopy coverage. This difference is probably due to high ambient temperatures and the high availability of basking sites in open habitats and suggests a thermal constraint on habitat use and time of activity for Ameiva in closed canopy habitats.