Herpetology Notes, volume 5: 49-58 (2012) (published online on 18 March 2012) Natural history of the tropical gecko Phyllopezus pollicaris (Squamata, Phyllodactylidae) from a sandstone outcrop in Central Brazil. Renato Recoder1*, Mauro Teixeira Junior1, Agustín Camacho1 and Miguel Trefaut Rodrigues1 Abstract. Natural history aspects of the Neotropical gecko Phyllopezus pollicaris were studied at Estação Ecológica Serra Geral do Tocantins, in the Cerrado region of Central Brazil. Despite initial prospection at different types of habitats, all individuals were collected at sandstone outcrops within savannahs. Most individuals were observed at night, but several specimens were found active during daytime. Body temperatures were significantly higher in day-active individuals. We did not detect sexual dimorphism in size, shape, weight, or body condition. All adult males were reproductively mature, in contrast to just two adult females (11%), one of which contained two oviductal eggs. Dietary data indicates that P. pollicaris feeds upon a variety of arthropods. Dietary overlap between sexes and age classes was moderate to high. The rate of caudal autotomy varied between age classes but not between sexes. Our data, the first for a population ofP. pollicaris from a savannah habitat, are in overall agreement with observations made in populations from Caatinga and Dry Forest, except for microhabitat use and reproductive cycle. Keywords. Cerrado, lizard, local variation, niche breadth, thermal ecology, sexual dimorphism, tail autotomy. Introduction information about aspects of the natural history (habitat Phyllopezus pollicaris (Spix, 1825) is a large-sized, use, morphology, diet, temperatures, reproductive nocturnal and insectivorous gecko native to central condition and caudal autotomy) of a population of South America (Rodrigues, 1986; Vanzolini, Costa P. pollicaris from Central Brazil. We discuss local and Vitt, 1980; Vitt, 1995). Currently, P. pollicaris is variation and compare our results with available data. considered to represent a complex of cryptic species (Gamble et al., 2012) which is widespread along the Materials and methods South American great diagonal of open formations (Vanzolini, 1968; 1988) ranging from the Chaco, Study area through the Brazilian Cerrado and Caatinga eastwards Field work was carried out in the Estação Ecológica Serra Geral to the coastal Atlantic Forest of north-eastern Brazil do Tocantins (EESGT), a large conservation unit in the Cerrado (Vanzolini, 1968; Rodrigues, 1986; Cei, 1993). The region of Central Brazil. The expedition was conducted with the presence of P. pollicaris has been frequently associated main objective of making an inventory of the herpetofauna of with rock outcrops (Rodrigues, 1986; Cei, 1993; Vitt, the EESGT (results in Recoder et al., 2011; Valdujo et al., 2011). The area is characterized by typical Cerrado vegetation compo- 1995; Werneck, Colli and Vitt, 2009). sed of extensive grasslands and savannahs, interspersed by palm Phyllopezus pollicaris is locally common but, despite marshes and gallery forests. The EESGT region has three main its widespread distribution, ecological knowledge levels of altimetric surfaces. The first is composed of a sandstone on the species is scarce. The available information plateau with elevations ranging between 800 and 900 m, which is based on a limited number of studied populations occupies the eastern portion contiguous with Planalto dos Gerais. (Rodrigues, 1986; Vitt, 1986; 1995; Dias and Lira- Isolated sandstone relicts are also present at the central portion of da-Silva, 1998; Werneck, Colli and Vitt, 2009) or on the Ecological Station. The second level composes an extensive sandy depression which resulted from erosion of the plateau, with anecdotal data (Vanzolini 1974; Vanzolini, Costa and elevations ranging between 400 and 550 m in the central, western Vitt, 1980; Cei, 1993). Thus, this work aims to provide and southern portions. The final level is an intermediary plateau crossing the station oriented NNW-SSE direction, with elevations ranging between 600 and 700 m. 1 Laboratório de Herpetologia, Departamento de Zoologia, Field data collection Instituto de Biociências, Rua do Matão, no 101, CEP 05508- Field work was conducted from the end of January through the 090, Universidade de São Paulo, São Paulo, Brazil; beginning of February 2008, at the end of the rainy season (Figure *Corresponding author; e-mail: [email protected] 50 Renato Recoder et al. Table 1. Morphological measurements, weight and body condition estimates of adult males, adult females and juveniles of Phyllopezus pollicaris from the EESGT. Data presents the average, followed by standard deviation, and minimum and maximum values between parentheses. Adult males Adult females Juveniles N=9 N=18 N=6 64.4 + 8.9 68.4+ 7.4 40.5+3.1 SVL (mm) (54.3–77.9) (56.3–78.4) (34.1–44.3) 28.6+3.9 30.1+3.5 18.1+1.7 TRL (mm) (23.9–34.7) (23.8–33.8) (15.7–20.1) 12.7+ 1.6 13.4+ 1.4 8.6+ 0.5 HW (mm) (10.6–15.2) (11.1–15.9) (7.7–8.9) 15.9+ 1.8 16.8+ 1.7 11.0 + 0.4 HL (mm) (13.8–18.5) (14.0–19.2) (10.3–11.5) 10.5+ 1.3 11.2+ 1.0 7.3+ 0.3 ML (mm) (9.0–12.5) (9.3–12.6) (6.8–7.7) 12.1+ 1.5 12.5+ 1.2 7.7+ 0.6 FL (mm) (10.2–14.2) (10.6–13.8) (6.8–8.2) 11.7+ 1.5 12.2+ 1.1 7.1+ 0.6 TL (mm) (10.0–14.0) (10.5–13.4) (6.2–7.6) 2.0 + 0.4 2.2+ 0.3 1.2+ 0.1 FTW (mm) (1.7–2.6) (1.7–2.6) (1.1–1.3) 6.7 + 2.8 8.2 + 2.8 1.6 + 0.6 Weight (g) (3.7–11.0) (4.1–11.5) (0.9–2.3) 3.35 + 1.49 3.81 +1.44 1.39+ 0.55 Body Condition (W/SVL) (1.78–5.95) (1.84–6.43) (0.70–1.90) 1). Two main sites were sampled: (1) the southern portion of the EESGT (general coordinates 11o 11’ S; 46o 50’ W), within the mu- nicipality of Almas, state of Tocantins, and (2) the eastern portion (general coordinates 10o 40’ S; 46o 09’ W), within the municipality of Formosa do Rio Preto, state of Bahia. Each locality was sam- pled during nine consecutive days by means of a set of nine lines of pitfall traps (40 buckets each) bordered by drift fences. The main types of available habitats (i.e. grasslands, typical open-sa- vannahs, rocky savannahs, palm marshes and gallery forest) were sampled in each locality. Diurnal and nocturnal active search was performed haphazardly in the vicinities of pitfall traps. Efforts of active search were not standardized, as the primary intention was to complement the results of pitfall trap sampling by means of searches for arboreal, rock-dwelling and large sized species. o Body temperatures (Tb; nearest 0,1 C) were taken with a quick- reading thermometer immediately upon capture. Subsequently, microhabitat temperature (Tss; temperature of the surface where the individual was first observed) and air temperature (Ta; tempe- rature five centimetres above substrate where the individual was Figure 1. Climate diagram of the municipality of Mateiros, first observed) were measured. Additionally, the hour of activity state of Tocantins, Brazil. Squares represent maximum and was recorded. Several available substrate temperatures were re- minimum temperatures for each month, bars represent mean corded at random within the sampling area with an infrared por- rain accumulated. Black arrow indicated period in which field table thermometer: temperatures of rock surface (Ts), temperatures work was carried out. in crevices less than five centimetres deep (T<5), and temperatures Natural history of the tropical gecko Phyllopezus pollicaris 51 Figure 2. Typical open savannah with sandstone outcrops where individuals were observed, at eastern portion of the Estação Ecológica Serra Geral do Tocantins (top); individual active by morning on rock surfaces (bottom). 52 Renato Recoder et al. Figure 3. The results of a principal component analysis on size-adjusted morphometric variables of adult male (black triangles) and females (gray circles) Phyllopezus pollicaris from the EESGT. The contribution of each component to total variance is presented between parentheses. Table 2. Scores of the Principal Component Analysis performed on size-adjusted morphometric variables of adult Phyllopezus pollicaris. The coefficients with significant correlation with the component are in bold. Individual contribution to total variation and cumulative contribution of each component are shown in the bottom. Characters PC1 PC2 TRL 0.17425 -0.42491 HW 0.49568 0.59285 HL 0.29050 0.72333 ML -0.02148 0.50903 FL 0.78709 -0.18713 TL 0.83678 -0.43406 FTW 0.71711 0.12758 % of Variance 31.36 22.20 % Cumulative 31.36 53.56 Natural history of the tropical gecko Phyllopezus pollicaris 53 in crevices deeper than five centimetres (T>5). Available substrate tivariate analysis of variance (ANOVA and MANOVA). Shape temperatures were taken at night (22:00 pm) and morning (11:00 variation was summarized with a Principal Component Analysis am) periods. Variation in air temperature was recorded hourly (PCA) performed using the residuals of the linear regression of with a HOBO data logger for eight consecutive days. the morphometric data on the SVL. The effect of environmental temperatures over body temperatures was investigated with mul- Laboratory data collection tiple linear regression analysis. Differences in tail-loss frequen- Specimens were euthanized by a lethal injection of anaesthetic, cies between sexes and age groups were tested using chi-square weighed to the nearest 0.1 g using Pesola© string balances, fixed test (χ2). We calculate estimations of complete tails for individuals using a 10% formalin solution and preserved in 70% ethanol.