ABSTRACT
This study records and analyzes the diversity and structure of a snake assemblage in a transition area between Cerrado and Caatinga, in the municipality of Castelo do Piauí, state of Piauí, comparing the distribution and similarity of the species composition with other open localities already studied in Brazil. We used three complementary sampling methods: time constrained search (TCS), pitfall traps with drift fences (PFT), and incidental encounters (IE). During the TCS and PFT, 912 hours/observer and 6,468 days/trap were used, respectively. We estimated 23 species of snakes for the locality, although only 19 species were recorded. Philodryas nattereri Steindachner, 1870 (n = 10), Liophis poecilogyrus (Schlegel, 1837) (n = 9), Liophis viridis Günther, 1862 (n = 8) and Thamnodynastes sp. (n = 8) were the most abundant species. Terrestrial, cryptozoic, and diurnal snakes predominated in the assemblage (Boidae = 2 species, Dipsadidae = 12, Colubridae = 2, Elapidae = 1, Viperidae = 2). The results indicate that the fauna of the locality is similar with that of other open formations, especially the Caatinga, corroborating previous floristic studies. Comparisons between snake assemblages analyzed by different authors suggest structural differences between the assemblages of the Cerrado and the Caatinga, contradicting the hypothesis of mixed composition of fauna in these biomes.
ABSTRACT
This study records and analyzes the diversity and structure of a snake assemblage in a transition area between Cerrado and Caatinga, in the municipality of Castelo do Piauí, state of Piauí, comparing the distribution and similarity of the species composition with other open localities already studied in Brazil. We used three complementary sampling methods: time constrained search (TCS), pitfall traps with drift fences (PFT), and incidental encounters (IE). During the TCS and PFT, 912 hours/observer and 6,468 days/trap were used, respectively. We estimated 23 species of snakes for the locality, although only 19 species were recorded. Philodryas nattereri Steindachner, 1870 (n = 10), Liophis poecilogyrus (Schlegel, 1837) (n = 9), Liophis viridis Günther, 1862 (n = 8) and Thamnodynastes sp. (n = 8) were the most abundant species. Terrestrial, cryptozoic, and diurnal snakes predominated in the assemblage (Boidae = 2 species, Dipsadidae = 12, Colubridae = 2, Elapidae = 1, Viperidae = 2). The results indicate that the fauna of the locality is similar with that of other open formations, especially the Caatinga, corroborating previous floristic studies. Comparisons between snake assemblages analyzed by different authors suggest structural differences between the assemblages of the Cerrado and the Caatinga, contradicting the hypothesis of mixed composition of fauna in these biomes.
ABSTRACT
This study records and analyzes the diversity and structure of a snake assemblage in a transition area between Cerrado and Caatinga, in the municipality of Castelo do Piauí, state of Piauí, comparing the distribution and similarity of the species composition with other open localities already studied in Brazil. We used three complementary sampling methods: time constrained search (TCS), pitfall traps with drift fences (PFT), and incidental encounters (IE). During the TCS and PFT, 912 hours/observer and 6,468 days/trap were used, respectively. We estimated 23 species of snakes for the locality, although only 19 species were recorded. Philodryas nattereri Steindachner, 1870 (n = 10), Liophis poecilogyrus (Schlegel, 1837) (n = 9), Liophis viridis Günther, 1862 (n = 8) and Thamnodynastes sp. (n = 8) were the most abundant species. Terrestrial, cryptozoic, and diurnal snakes predominated in the assemblage (Boidae = 2 species, Dipsadidae = 12, Colubridae = 2, Elapidae = 1, Viperidae = 2). The results indicate that the fauna of the locality is similar with that of other open formations, especially the Caatinga, corroborating previous floristic studies. Comparisons between snake assemblages analyzed by different authors suggest structural differences between the assemblages of the Cerrado and the Caatinga, contradicting the hypothesis of mixed composition of fauna in these biomes.
ABSTRACT
A structured snake inventory was carried out at the Base Operacional Geólogo Pedro de Moura (BOGPM), located at the Urucu Petrol Basin, Municipality of Coari, Amazonas, during 2003, 2004 and 2007. Throughout four sampling expeditions (51 collection days), seven species of snakes, belonging to seven families and 33 genera, were recorded. Four complementary sampling methods were used: pitfall traps with drift fence, occasional encounters, time-limited search on foot and time-limited search by car. Of the 47 collected species Liophis reginae (n= 14), Philodryas viridissima (n= 9), Philodryas boulengeri (n= 7) and Oxybelis fulgidus (n= 7) were the most abundant in the region. The highest number of species and specimens was obtained by the time-limited search by car (n=52.8%). Previous studies indicate that localities south of the Amazonas river (such as the eastern region of Pará and Tucuruí, state of Para, and Samuel Hydroelectric Plants, state of Rondônia) present a greater richness when compared to those north of the Amazonas river (such as the mucipality of Manaus, INPA-WWF Reserve and Balbina Hydroelectric Plant, state of Amazonas).Thus, it is possible to infer that the snake inventory in Urucu region is not yet complete, requiring more sampling efforts so that new records can be obtained for the area.
Um inventário estruturado de serpentes foi realizado na Base Operacional Geólogo Pedro de Moura (BOGPM), localizada na Bacia Petrolífera de Urucu, Município de Coari, Amazonas, nos anos de 2003, 2004 e 2007. Nas quatro expedições realizadas (51 dias de coleta) foram registradas 47 espécies de serpentes, pertencentes a sete famílias e 33 gêneros. Foram utilizados quatro métodos complementares de amostragem de serpentes: armadilha de interceptação e queda, encontros ocasionais, procura limitada por tempo a pé e procura limitada por tempo de carro. Das 47 espécies coletadas, Liophis reginae (n= 14), Philodryas viridissima (n= 9), Philodryas boulengeri (n= 7) e Oxybelis fulgidus (n= 7) foram as mais abundantes em toda região. O maior número de espécies e espécimes foi registrado pela procura limitada por tempo de carro (52,8%). Estudos anteriores indicam que as localidades ao sul do Rio Amazonas (como região Leste do Pará, Usina Hidrelétrica de Tucuruí, Estado do Pará, e de Samuel, Estado de Rondônia) apresentam maior riqueza quando comparadas às regiões ao norte do Amazonas (como Município de Manaus, Reserva do INPA-WWF e Usina Hidrelétrica de Balbina, Estado do Amazonas). Desta forma, é possível inferir que o levantamento das serpentes da região de Urucu ainda não esteja completo, sendo necessário um maior esforço de coleta para que novos registros sejam adicionados para a área.