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Corresponding author: Bruno F. Fiorillo ( ferreto_74@hotmail.com ) Academic editor: Robert Jadin
© 2020 Bruno F. Fiorillo, Bruno R. da Silva, Frederico Alcântara Menezes, Otavio A. V. Marques, Marcio Martins.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Fiorillo BF, Silva BR, Menezes FA, Marques OAV, Martins M (2020) Composition and Natural History of Snakes from Etá Farm region, Sete Barras, south-eastern Brazil. ZooKeys 931: 115-153. https://doi.org/10.3897/zookeys.931.46882
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Approximately 140 snake species are known to occur in the Atlantic Forest with nearly half being endemic to this ecoregion. However, the Atlantic forest is one of the most threatened tropical ecoregions, with only 16% of its original area remaining as forest. This extensive habitat loss must have had a negative effect on its snake fauna. Indeed, 53% of the threatened snakes of Brazil occur in the Atlantic forest. Therefore, basic natural history information that can potentially contribute to the conservation of Atlantic forest snakes are urgently needed. Here the natural history of a snake assemblage at Etá Farm region, Sete Barras municipality, south-eastern Brazil is described, and a visual guide and an identification key provided that can be used by researchers and local people to identify snakes from this region. Most of the species found in the field use both open areas and forests, are primarily terrestrial, present diurnal activity, and include frogs in their diet. A higher number of enlarged follicles, eggs, and/or embryos were recorded during the warm and rainy season. Seventeen different types of defensive tactics were recorded in the species found in the field. This study provides useful information for understanding the structure of snake assemblages of the Atlantic Forest and is potentially useful for conservation assessments and for designing conservation plans.
banana plantation, diet, habitat, peach palm plantation, rainforest, reproduction, reptiles
Natural history information, what organisms do in their respective environments, including interactions between them (
The Atlantic forest of eastern Brazil harbours a very rich snake fauna, with approximately 140 species, representing 34% of the 412 species of snakes known to occur in Brazil (
Here we provide basic natural history information for an Atlantic Forest snake assemblage from south-eastern Brazil. We sampled pristine along with disturbed habitats, thus assessing the ability of the Atlantic forest snakes to persist in disturbed habitats. For each species we provide primary information on habitat and micro-habitat use, time of activity, feeding habits, reproduction and defence. We also provide a short review of the natural history of each species based on our results and on previously published accounts.
The primary information used in this study was obtained between April 2013 and March 2014 at the region of Etá Farm (24°19'13"S, 48°7'3"W) in the Sete Barras municipality, São Paulo state, south-eastern Brazil. The area is located within the Atlantic forest in a hillside forest formation (
Phytosociological and floristic studies have shown high richness of tree and shrub species in this type of Atlantic forest formation (
Field data were collected by two researchers for 14 days per month, from April 2013 to March 2014, for a total sample time of 168 days. Snakes were sampled with pitfall traps with drift fences (Greenberg et al. 1994,
Satellite images (source: Google Earth) A the region where the study area (light orange rectangle) is located in the southern São Paulo State and the group of continuous protected areas (in light green) that encompasses most of the primary forests of this region (AR = Parque Estadual Turístico do Alto Ribeira; CB = Parque Estadual Carlos Botelho; IV = Parque Estadual Intervales; XI = Estação Ecológica de Xituê) as well as the location of the Etá Farm region (rectangle) B the region of the Etá Farm, Sete Barras Municipality where 1 indicates the Etá Farm administrative buildings, 2–4 indicate areas of forest, 5 and 6 indicate peach palm plantations; 7 indicates abandoned banana plantation, and 8 indicates an agricultural settlement.
Habitat use was recorded through active search for individuals (made only at night), describing the habitats (e. g., open area, forest, banana plantation) and micro-habitats used by each snake (fossorial, aquatic, terrestrial or arboreal) and perch height (in case of arboreal species). To characterise micro-habitats we used only information obtained during active searches; for individuals collected with pitfall traps, only vegetation cover (forest, peach palm or banana plantation) was considered.
To describe diet, collected specimens were dissected through an incision in the ventral region. Food items were identified to the lowest possible taxonomic rank using taxonomic keys, identification guides, specimens deposited in scientific collections and help from experts. Whenever the prey came from a snake captured in a pitfall trap, this information was included, given the possibility of the snake having ingested prey that had also fallen in the trap (
To describe reproductive condition, we recorded the length of the largest follicle, egg or embryo, and number of vitellogenic follicles (> 10 mm), eggs or embryos in every month of collection. Specimens collected in the field in the study area and specimens from the herpetological collection of the Butantan Institute were dissected for this purpose.
Behavioural descriptions are based on observations made over short periods of time (ad libitum and sequence samplings;
With a sampling effort of 168 days of fieldwork, including 558 person-hours of visual search, we found 255 individuals of 17 species of snakes (14 genera, four families) at the Etá Farm region. Additionally, we included Corallus cropanii to our study because it was found previously by other researchers in our study area (
Number of individual snakes found in the Etá Farm region, Sete Barras, SP, Brazil, in forests and disturbed areas, considering all sampling methods. Forest includes forests and forest borders; Disturbed includes banana plantations, peach palm plantations, and other disturbed areas (roads, pastures, areas around houses); N = number of specimens recorded. The asterisk indicates a species that was found by other researchers in our study area (
Forest | Disturbed | N | |
---|---|---|---|
Boidae | |||
Corallus cropanii* | 1 | 1 | |
Colubridae | |||
Chironius exoletus | 1 | 1 | |
Chironius fuscus | 1 | 7 | 8 |
Chironius laevicollis | 3 | 1 | 4 |
Spilotes pullatus | 15 | 15 | |
Dipsadidae | |||
Dipsas neuwiedii | 25 | 25 | |
Echinanthera cephalostriata | 2 | 1 | 3 |
Erythrolamprus aesculapii | 2 | 3 | 5 |
Erythrolamprus miliaris | 22 | 53 | 75 |
Helicops carinicaudus | 7 | 6 | 13 |
Oxyrhopus clathratus | 3 | 9 | 12 |
Sordellina punctata | 5 | 2 | 7 |
Taeniophallus bilineatus | 2 | 2 | |
Tomodon dorsatus | 3 | 3 | |
Xenodon neuwiedii | 2 | 4 | 6 |
Elapidae | |||
Micrurus corallinus | 1 | 5 | 6 |
Viperidae | |||
Bothrops jararaca | 4 | 19 | 23 |
Bothrops jararacussu | 9 | 38 | 47 |
TOTAL | 63 | 193 | 256 |
Besides the 17 species we found during our fieldwork at Fazenda Etá region and C. cropanii (
Among the species we found in the field, most used forested areas (> 70% of species), were primarily terrestrial (70%), showed diurnal activity (> 58%), and included frogs in their diet (> 50%; information supplemented with data from the literature). Only those which consumed endothermic prey and Dipsas neuwiedi showed nocturnal activity. However, there was a relatively high percentage (30%) of semi-arboreal species, observed almost exclusively in open areas or forest edges, all anuran specialists (except for Spilotes pullatus) and belonging to the family Colubridae.
In addition to species that were semi-arboreal and anuran specialists, the mollusc-specialist species D. neuwiedi and T. dorsatus were also found exclusively in open areas. Only T. bilineatus proved to be the most limited to the forest habitat (N = 2), particularly to a cryptozoic micro-habitat (see Habitat Use of Taeniophallus bilineatus under Natural history accounts). The species E. miliaris and B. jararacussu showed the broadest spectrum of the assemblage in terms of resource use, as both widely used open and forested areas and included 3 and 4 different types of prey in their diet, respectively.
The viperids B. jararaca and B. jararacussu and the dipsadids D. neuwiedii and O. clathratus were the species most commonly found in disturbed areas such as plantations, around houses and even inside houses. Particularly for O. clathratus, 75% of observations occurred in disturbed habitats; the remaining took place in the forest.
Among the snake specimens whose stomach contents were analysed, 82 individuals, belonging to eleven different species, had prey in their digestive tracts. Of those, most have ingested frogs (61%), followed by mammals (18.3%), molluscs (11%), snakes (3.7%), fishes (2.4%), non-mollusc invertebrates (leech and centipede) (2.4%), and lizards (1.2%) (Table
Food items found in the digestive tract of snakes from the region of Etá Farm region, Sete Barras, SP, Brazil. N = number of snakes with respective stomach or intestinal contents, or observation.
Family/Species | N | Stomach contents |
---|---|---|
Colubridae | ||
Chironius laevicollis | 21 | Leptodactylus latrans (Anura, Leptodactylidae)1 |
Spilotes pullatus | 11 | Unidentified rodent hair |
Dipsadidae | ||
Dipsas neuwiedi | 21 | Limax cf. flavus (Molusca, Limacidae)1 |
11 | Meghimatium pictum (Molusca, Philomycidae)1 | |
21 | Unidentified Molusca1 | |
41 | Phyllocaulis sp. (Molusca, Philomycidae)1 | |
Erythrolamprus aesculapii | 11 | Snake scales |
11 | Sibynomorphus neuwiedi (Serpentes, Dipsadidae)1 | |
Erythrolamprus miliaris | 11;12 | Unidentified frog fragments2 |
11;52 | Fragments of Leptodactylus sp. (Anura, Leptodactylidae)1,2 | |
22 | Fragments of Rhinella sp. (Anura, Leptodactylidae)2 | |
32 | Leptodactylus latrans (Anura, Leptodactylidae)2 | |
11;42 | Leptodactylus notoaktites (Anura, Leptodactylidae)1,2 | |
11; 142 | Physalaemus spiniger (Anura, Leptodactylidae)1, 2 | |
12 | Placosoma glabellum (Lacertilia, Gymnophtalmidae)2 | |
22 | Rhinella hoogmoedi (Anura, Leptodactylidae)2 | |
22 | Rhinella icterica (Anura, Bufonidae)2 | |
12 | Rhinella ornata (Anura, Bufonidae)2 | |
11 | Synbranchus marmoratus (Synbranchiformes, Synbranchidae)1 | |
Helicops carinicaudus | 11 | Characidium sp. (Characiformes, Crenuchidae) |
11 | Unidentified frog fragments | |
11 | Leptodactylus latrans (Anura, Leptodactylidae)1 | |
Oxyrhopus clathratus | 12 | Monodelphis americana (Didelphimorphia, Didelphidae)2 |
Sordellina punctata | 11 | Leech (Annelida, Hirudinea)1 |
Xenodon neuwiedii | 11 | Unidentified frog fragments |
11 | Fragments of Rhinella hoogmoedi (Anura, Bufonidae)1 | |
12 | Rhinella icterica (Anura, Bufonidae) 2 | |
Viperidae | ||
Bothrops jararaca | 11 | Akodontini (Rodentia)1 |
21 | Unidentified rodent hair | |
Bothrops jararacussu | 11 | Akodon sp. (Rodentia, Cricetidae)1 |
21 | Akodontini (Rodentia, Cricetidae)1 | |
11 | Brucepattersonius sp. (Rodentia, Cricetidae)1 | |
11 | Didelphis cf. aurita (Marsupialia, Didelphidae)1 | |
11 | Fragments of Leptodactylus sp. (Anura, Leptodactylidae)1 | |
31 | Fragments of Leptodactylus latrans (Anura, Leptodactylidae)1 | |
11 | Fragments of Hylidae (Anura, Leptodactylidae)1 | |
11 | Unidentified mammal fragments | |
11 | Centipede (Scolopendromorpha, Scolopendridae)1 | |
11 | Oligoryzomys sp. (Rodentia, Cricetidae)1 | |
31 | Unidentified rodent | |
11 | Sordellina punctata (Serpentes Dipsadidae)1 |
Although, in qualitative terms, E. miliaris and B. jararacussu showed a greater diversity of items in their diets, they may be considered specialists in frogs (> 95% of the diet of E. miliaris) and small mammals (> 58% of the diet of B. jararacussu), respectively. However, most of the records obtained for E. miliaris came from individuals caught in pitfall traps (> 87% of cases). Hence, part of the frogs may have been opportunistically consumed by this species (the finding of 14 specimens of E. miliaris captured in pitfall traps, that ingested P. spiniger, supports this assumption). Only four individuals of this species were captured by other capture methods, one of which had consumed a fish.
Of the specimens examined, 28 were reproductive females containing vitellogenic follicles, eggs or embryos. In the three families, as with activity, larger follicles were found during the Austral Spring, with the largest vitellogenic follicles, as well as eggs and embryos, occurring from September to October, except for one specimen of Erythrolamprus aesculapii that had vitellogenic follicles during the month of July (Austral Winter). Over the sampling period, only one single mating behaviour was observed for S. pullatus, in September (see Natural history accounts).
A total of 17 different defensive tactics was recorded for the assemblage studied, with some variations and combinations of them (Table
Defensive tactics of snakes from the Etá Farm region, Sete Barras, SP, Brazil. CB = compress body while raising head; CD = cloacal discharge; SC = S-coil; DM = display buccal mucosa; DV = display ventral posterior region; EM = perform erratic movements; FB = flatten body; HH = hide head; IG = inflate gular region; MI = mimicry; OM = open mouth; RB = rotate body; RH = raise head; ST = strike; TD = tail display; TH = triangulate head; VT = vibrate tail. The numbers indicate field observations and an “X” indicates data from the literature (
Species | CB | CD | SC | DM | DV | EM | FB | HH | IG | MI | OM | RB | RH | ST | TD | TH | VT |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chironius exoletus | X | 1 | X | 1 | 1 | ||||||||||||
Chironius fuscus | X | X | X | X | X | X | 2 | X | |||||||||
Chironius laevicollis | X | X | X | X | X | X | X | ||||||||||
Spilotes pullatus | X | X | 10 | 1 | X | 4 | 4 | ||||||||||
Dipsas neuwiedi | 4 | X | 1 | X | X | 19 | |||||||||||
Echinanthera cephalostriata | X | X | 1 | ||||||||||||||
Erythrolamprus aesculapii | X | X | X | X | X | X | |||||||||||
Erythrolamprus miliaris | X | 20 | 2 | 5 | 3 | ||||||||||||
Helicops carinicaudus | X | X | X | 4 | |||||||||||||
Oxyrhopus clathratus | X | 1 | X | X | |||||||||||||
Sordellina punctata | 2 | X | |||||||||||||||
Taeniophallus bilineatus | X | X | |||||||||||||||
Tomodon dorsatus | X | X | X | X | X | X | |||||||||||
Xenodon neuwiedii | X | X | 1 | X | X | 1 | X | ||||||||||
Micrurus corallinus | X | 1 | X | X | X | ||||||||||||
Bothrops jararaca | X | X | 4 | 6 | |||||||||||||
Bothrops jararacussu | X | X | 2 | 5 |
This large species (maximum SVL = 1510 mm;
This is an aglyphous species of medium size (maximum SVL = 790 mm; N = 1). Only one individual was found, in the peach palm plantation, on the vegetation at 0.5 m above the ground, during the day, in November. The available information indicates that it is semi-arboreal and diurnal (
This is an aglyphous species of medium size (maximum SVL = 919 mm; N = 8). It was found crossing an unpaved road, always near the forest edge (N = 6), and on a trail in the forest near the abandoned banana plantation, lying coiled up on a tree at 1.5 m above the ground (N = 1). One juvenile was found while crossing a paved road close to the urban area of Sete Barras, during the day. The available information indicates that it is diurnal and semi-arboreal, but forage mainly on the ground of the forests (
This is an aglyphous species of large size (maximum SVL = 1650 mm; N = 4). One individual was found on the ground, during the day, moving through the peach palm plantation; another was foraging on the forest floor at the margins of the Etá River during the day. Before being captured, the individual found on the trail quickly climbed a tree to a height of approximately 3 m. One individual was observed in a shallow pond at the edge of the forest, “yawning” as if it had just ingested something, shortly before swimming away, also during the day. The available information indicates that it is diurnal and terrestrial, being arboreal during the juvenile stage (
This is an aglyphous species of large size (maximum SVL = 1830 mm; N = 15). It was found in a pile of wood next to a house in an operating banana plantation (N = 4), in an abandoned banana plantation (N = 1), in peach palm plantations (N = 2), on the edge of the forest (N = 1), in a pasture (N = 1) and crossing a paved road in areas surrounded by forest and pasture (N = 2). Three run-over individuals were collected on an unpaved road near the edge of forest. The available information indicates that it is semi-arboreal and diurnal (
This is an aglyphous species of medium size (maximum SVL = 643 mm; N = 31). It was found mostly in the peach palm plantation (N = 15), with only one individual captured in a pitfall trap. It was found also around the houses (N = 5) and crossing the unpaved road at night (N = 5). One individual was found resting under the lid of one of the pitfall trap buckets during the day. We have no information on habitat use for the other five individuals. The available information indicates that it is nocturnal and semi-arboreal (
This is an aglyphous species of small size (maximum SVL = 399 mm; N = 3). Individuals were found crossing the road near forest and pasture areas during the day (N = 2), and moving in the leaf litter in the forest at night (N = 1). In a study at Serra do Medanha, Rio de Janeiro (
This is an opistoglyphous species of medium size (maximum SVL = 827 mm; N = 5). Four individuals were found on an unpaved road: two moving near a pasture, one near an operating banana plantation and one crossing an unpaved road near the forest edge, all during the day. The last individual was found inside the forest. The available information indicates that it is terrestrial, cryptozoic and primarily diurnal (
This is an aglyphous species of medium size (maximum SVL = 1000 mm; N = 74). It was found in all sampled vegetation types and captured, in most cases, in pitfall traps (17 in the abandoned banana plantation, 22 in forest and 23 in the peach palm plantation); it was also found in other disturbed areas (N = 13). When found in the traps, all individuals submerged into the water accumulated in the buckets. Most individuals were seen in the abandoned banana plantation, moving or resting in the undergrowth (N = 4), or foraging at the edge of flooded vegetation (N = 1); in the forest, moving on the ground or on the leaf litter (N = 2); and, in the peach palm plantation, in water puddles (N = 2) or undergrowth (N = 1). In visual searches and occasional encounters, individuals were also found at the edge of the forest (N = 1), in pasture areas (N = 3), in a swamp (N = 1), and around houses (N = 2). Some individuals were captured on the unpaved road, always near flooded areas (N = 3) and one adult individual was found in a puddle in an open area near the forest edge. Two juveniles were captured in very disturbed habitats, one in the sink in a house at 12:00 h and another in an operating banana plantation, moving over rocks at 15:30 h. Additionally, four individuals were found on the unpaved road, one crossing it near a swamp during the day, and another run over by a car near the peach palm plantation at 06:00 h. Observations of individuals moving were always in daytime. The available information indicates that it is semi-aquatic and both diurnal and nocturnal (
This is an aglyphous species of medium size (maximum SVL = 623 mm; N = 12). Thirteen individuals were found in the field; of those, three in the peach palm plantation, with one individual captured in a pitfall trap, and the other three in a stream at the edge of forest, in the water, all apparently active in late afternoon. Three individuals were captured on the unpaved road, all moving during the day. The other captured individuals (N = 7) moved across floodplains on the edge of the forest, also in late afternoon. Literature records of activity were made during both day and night (
This is an opisthoglyphous species of medium size (maximum SVL = 710 mm; N = 12). It was found mainly around houses trying to climb walls at dusk (N = 6), run over on the unpaved road next to the forest edge (N = 2), and moving on the ground in the forest at night (N = 1). One adult male was caught while crossing the unpaved road near the edge of forest at 05:30 h. Three individuals were captured in other disturbed habitats. The available information indicates that it is terrestrial and both diurnal and nocturnal (
This is an aglyphous species of small size (maximum SVL = 461 mm; N = 7). It was captured in a pitfall trap in the forest (N = 1), crossing an unpaved road near the margins of the Etá River (N = 4), and in a pasture area (N = 1), at dusk (N = 3) and at night (N = 1). One individual was captured in another disturbed habitat. One individual had been ingested by an individual of B. jararacussu at the edge of the forest, at night. The available information indicates that this is a semi-aquatic, primarily diurnal species (
This is an aglyphous species of small size (maximum SVL = 258 mm; N = 2). Two individuals were found, one captured in a pitfall trap in the forest, the other moving along the forest edge in the morning. The available information indicates that it is terrestrial and diurnal (
This is an opisthoglyphous species of small–medium size (maximum SVL = 540 mm, N = 3). One adult female was found in July around a house, one adult male was found on the unpaved road in December and another adult male was found run-over near the peach palm plantation in January. The available information indicates that it is terrestrial, cryptozoic and diurnal (
This is an aglyphous species of medium size (maximum SVL = 555 mm; N = 6). It was captured in a pitfall trap in the forest (N = 1). One juvenile was captured as it moved through the leaf litter during the day, at 08:20 h, and one adult male was captured while crossing an unpaved road at 10:50 h. One individual was found on the peach palm plantation and another on an unpaved road, near a pasture area, during the day. The last individual was caught in unpaved road close to disturbed areas. The available information indicates that it is diurnal and terrestrial (
This is a proteroglyphous species of medium size (only juveniles were captured, with maximum SVL = 251 mm; N = 5; adults exceed 900 mm in total length;
This is a solenoglyphous species of large size (maximum SVL = 1220 mm; N = 23). It was found in all sampled vegetation types (eight individuals in peach palm plantation, four in forests, and one in the abandoned banana plantation), but never in pitfall traps. It was also found in operating banana plantations (N = 5). The other five individuals were caught in other disturbed habitats. Most individuals found were coiled up in the undergrowth during the day, in the peach palm plantation; one individual was found around houses and two on an unpaved road, one of them near the forest edge and the other in a pasture area. One adult male was found moving on the ground in the afternoon (15:00 h) in the abandoned banana plantation, one juvenile was found moving over a bromeliad on a fallen trunk at night (see also
This is a solenoglyphous species of large size (maximum SVL = 1150 mm; N = 47). It was found in all sampled vegetation types (23 individuals in the peach palm plantation, six in forest and four in banana plantations), coiled up in the undergrowth, often at the base of the peach palms (N = 17), in open areas or on the leaf litter in the forest (N = 4); only two juveniles were captured in pitfall traps, in the abandoned banana plantation and the peach palm plantation. Nine individuals were found on the unpaved road, three of them at the edge of forest, one of which had just ingested an individual of Sordellina punctata, and three near pasture areas. The other five individuals were caught in other disturbed habitats. The available information indicates that it is terrestrial and frequently found close to watercourses; it has mostly nocturnal activity, although juveniles and eventually adults may hunt during the day (
The snake assemblage of the Etá Farm region has a species composition similar to those of other studied assemblages in the Ribeira River Valley (e.g.,
Of the species recorded in the study area, most used both forested (or were at least observed in forest edges) and open areas, except for C. exoletus, D. neuwiedi, S. pullatus, and T. dorsatus, which were observed only in disturbed areas (banana and peach palm plantations). The peach palm plantations, surrounded by forested areas may be functioning as routes from one edge to the other of the forested areas, and as foraging sites (as they have large quantities of frogs and molluscs; see Fiorillo et al. 2018). However, the edges of a given habitat tend to be hostile to organisms adapted to living in its interior and may contain both competitors and predators (Andrén and Angelstam 1988,
The colubrids of the assemblage, as well as the xenodontines, are mostly anuran specialists (Marques et al. 1998,
The nocturnal and terrestrial species, B. jararaca, B. jararacussu, and O. clathratus show similar diet and were all found in both open, disturbed areas and in forested areas. Although marsupials (e.g., Monodelphis americana) were restricted to forested areas, rodents were abundant in both habitat types. However, juveniles of these species feed on ectothermic prey (O. clathratus feeds on lizards and Bothrops spp. feeds mainly on frogs). It is known that O. clathratus is occasionally found in open and disturbed areas (
Although annelids have been previously reported for the diet of S. punctata (
Most individuals were found during the hot and rainy season from September to March, when most species show reproductive activity, as may be seen by the presence of vitellogenic follicles for some species and mating (e.g., S. pullatus). This seasonal activity peak has been reported for other assemblages of Neotropical snakes (
The reproductive cycle of another member of the tribe Xenodontini, E. miliaris, varies along its distribution and, although vitellogenic follicles were observed from April to August (two individuals), the population of the Etá Farm region is characteristic of the southern coastal region of the Atlantic Forest, where the reproductive cycle of this species may be seasonal (
The results described herein for the reproduction of B. jararaca and B. jararacussu corroborate the results of other studies that describe the reproductive phenology for the genus Bothrops (
Most defensive tactics observed at the Etá Farm were apparently aimed at visually oriented predators such as birds (especially birds of prey), important predators of Neotropical snakes, and some mammals (
Another defence shown by many species was cryptic colouration (82%), which is common for diurnal species (58% of the assemblage; Martins & Oliveira, 1998). In contrast, only one species showed aposematic colouration (M. corallinus) and two (E. aesculapii and O. clathratus) are supposed mimics of the coral snakes (
A poorly documented visual defensive behaviour was reported for E. miliaris at Fazenda Etá (
The region of the Etá Farm harbours a rich snake fauna that is similar in composition to those of other snake assemblages in the Ribeira River Valley and includes one threatened species. This study contributed to the knowledge of the snake fauna of this region also by providing five new records for the Sete Barras Municipality. The detailed natural history information provided herein may be used in the assessment of the conservation status of these snakes and in the definition of action plans aiming to conserve this rich and biologically diverse fauna.
1 | Loreal pit present; solenoglyphous dentition; keeled dorsal scales | Viperidae |
– | Labial pits present; aglyphous dentition; smooth dorsal scales; large size | Boidae |
2 | Labial pits absent; small size; stout body; usually 21 or 23, rarely 25 midbody dorsal scale rows; 164–183 ventral plates; 15–19 maxillary teeth | Tropidophiidae (Tropidophis paucisquamis) |
– | Proteglyphous dentition; small black eyes; loreal shield absent; coral colour pattern, with single black rings between two narrow white rings | Elapidae (Micrurus corallinus) |
3 | Aglyphous or opistoglyphous dentition; top of head covered by large, distinct and symmetrical scales | Colubridae and Dipsadidae |
Viperidae
1 | Dorsal spots in inverted “V” shape, bordered by lighter colours; belly lighter with irregular spots; 20–37 dorsal scale rows; 170–216 ventral plates; 44–71 subcaudal plates; 6–10 supralabial scales | Bothrops jararaca |
– | Trapezoid dorsal spots, bordered by lighter colours; light-yellow belly; 23–29 dorsal scale rows; 166–186 ventral scales; eight supralabial scales | Bothrops jararacussu |
Boidae
1 | Olive-beige dorsum, with dark-brown rhomboidal spots from the neck to half of the tail; yellow ventral scales; 29–32 dorsal scale rows at midbody | Corallus cropanii |
– | Extremely variable dorsal patterns, from grey to brown, yellow to orange and red; cream to light grey belly; 47–63 dorsal scale rows at midbody | Corallus hortulanus |
Colubridae and Dipsadidae
1 | Even number of dorsal scale rows | 2 |
– | Odd number of dorsal scale rows | 7 |
2 | More than 14 dorsal scale rows at midbody; apical pits present; dorsal background black; yellow belly colour invades the dorsolateral region | Spilotes pullatus |
– | 10 to 12 dorsal scale rows at midbody; single cloacal plate | 3 |
3 | 10 dorsal scale rows at midbody; dorsal colour brown with shades of olive; keeled paravertebral scales; maxillary teeth 39–51 | Chironius fuscus |
– | 10 or 12 dorsal scale rows at midbody; apical pit single and only on the neck scales | 4 |
4 | Adults with head, supralabial scales and anterior region of the body black; yellowish belly; juveniles are born completely green; 156–165 ventral scales; maxillary teeth 32–39 | Chironius laevicollis |
– | Divided cloacal shield | 5 |
5 | Eight posterior dorsal scale rows; anterior third of body olive green, turning to brownish in the other two thirds; light belly; 123–162 ventral scales; 111–160 subcaudal scales; 24–34 maxillary teeth | Chironius exoletus |
– | Ten posterior dorsal scale rows. | 6 |
6 | Light green dorsum; belly light with shades of yellow; 163–174 ventral scales; 156–169 subcaudal scales; 32–37 maxillary teeth | Chironius foveatus |
– | Dorsal colour olive green with a lighter vertebral stripe; yellow belly; 149–169 ventral scales; 121–157 subcaudal scales; 28–40 maxillary teeth | Chironius bicarinatus |
7 | 17 or less dorsal scale rows at midbody | 8 |
– | 19 or more dorsal scale rows at midbody | 18 |
8 | 15 dorsal scale rows at midbody | 9 |
– | 17 dorsal scale rows at midbody | 13 |
9 | Big black eyes; coral colour pattern; opistoglyphous dentition | Erythrolamprus aesculapii |
– | Medium-sized eyes; colour pattern not coral-like | 10 |
10 | Top of head with several spots; aglyphous dentition; vertebral scale row distinctly larger than the other dorsal scales; belly with thin spots, forming irregular and rather interrupted longitudinal lines, 161–184 ventral scales; 56–83 subcaudal scales | Dipsas neuwiedi |
– | Laterally compressed body; head extremely distinct from the body; large eyes | 11 |
11 | A pair of parallel spots on top of head; irregular dorsal spot pattern; slightly enlarged vertebral scale row; 11–15 maxillary teeth | Dipsas albifrons |
– | A pair of white-bordered ocelli on top of head; beige dorsum, with dark round, well-defined blotches, thinly bordered by white | Dipsas alternans |
12 | Top of head blotched to mostly immaculate, but never with distinctive inverted U or V shaped blotches with light centres | Dipsas variegata |
– | Head with or without large parietal spots, otherwise mostly immaculate; 16–26 dorsal blotches | Dipsas indica |
13 | Dark oral lining; opistoglyphous dentition; large fangs; 134–143 ventral scales; 31–28 subcaudal scales; eight or less maxillary teeth | Tomodon dorsatus |
– | Light oral lining | 14 |
14 | Body uniformly black, with a series of light lateroventral spots; light spots on the supralabial scales; medium-sized eyes; subelliptical pupils; 135–174 ventral scales; 36–57 subcaudal scales | Sordellina punctata |
– | Each dorsal scale with a lighter centre, with dark borders; medium-sized eyes; 142–171 ventral scales; 39–64 subcaudal scales | Erythrolamprus miliaris orinus |
15 | Well-defined line along the canthus rostralis from the snout to the post-ocular region; top of head, dark; yellow belly; 8–23 maxillary teeth | Taeniophallus bilineatus |
– | Supralabial scales and chin region usually stained by black; no postocular stripe; 51–82 subcaudal scales; less than 140 ventral scales | Taeniophallus persimilis |
16 | Continuous lateral postocular stripe; white lateral line at the fourth dorsal row; light brown dorsum; yellow belly, with a pair of black dots on each ventral scale; 142–160 ventral scales; 80–100 subcaudal scales | Echinanthera cephalostriata |
– | A pair of light spots on the occipital region; dark middorsal band on the neck, usually with irregular borders | Echinanthera undulata |
17 | Supracephalic dark colouration extends to the middle of the dorsum, creating a dark dorsal band that contrasts with the paravertebral ground colour at least on the neck; anterior part of the dark pleural band usually regularly edged | Echinanthera cyanopleura |
– | Body strongly laterally compressed and long; head very distinct from the body; large eyes; elliptical pupil; vertebral dorsal scale row different from the paravertebral rows; dorsum brown with dark diamond-shaped blotches | Imantodes cenchoa |
18 | Single internasal shield, dark-brown or black dorsum; belly cream with two (sometimes three) medial rows of black semilunar marks; 130–148 ventral scales; 48–73 subcaudal scales | Helicops carinicaudus |
– | Paired internasal scales | 19 |
19 | Head uniformly black; long snout; numerous bands along the body, uniformly distributed and not continuous on the belly; 183–221 ventral scales; 46–88 subcaudal scales | Oxyrhopus clathratus |
– | Thin and laterally compressed body; head very distinct from the body; large red eyes; long, thin tail; anterior maxillary teeth longer than the rear ones; some vertebral scales are red or orange; the red spots on the dorsum occupy 4–7 scale rows | Siphlophis pulcher |
20 | Black or dark-brown colouration; juveniles have a white stripe on the head and a dark wine-red nuchal stripe; 198–243 ventral scales; 70–97 subcaudal scales; vertical pupils; smooth dorsal scales | Clelia plumbea |
– | Non-globular eye; cylindrical body; thick neck; intensely pigmented gular region; 142–167 ventral scales. | Thamnodynastes nattereri |
21 | Dorsoventral compression of the body; oblique dorsal scale rows; aglyphous dentition; 6–14 maxillary teeth, with additional pair of large laminate rear fangs | Xenodon neuwiedii |
– | Light brown dorsum, with square-shaped blotches; head, distinct from the body; laterally compressed body; slightly keeled dorsal scales | Tropidodryas serra |
We thank M. M. Mickenhagen for allowing our work at Etá Farm, V. Gonçalves for help in fieldwork. BFF thanks FAPESP for fellowships (2014/23267-5 and 2014/11855-0) and MM thanks CNPq for fellowships (302953/2012-4 and 306961/2015-6). This study was funded by a grant from FAPESP (2011/50206-9).
Specimen identifications
Explanation note: List of collected and/or examined specimens and their identifications and museums.