49 Reproducive ecology and d iet of the fossorial snake Phalotris la iv ita tus in the Brazilian Cerrado Henrique B. Braz, Karina N. Kasperoviczus & Selma Maria Almeida-Santos Laboratório de Ecologia e Evolução, Insituto Butantan, CEP 05503-900, São Paulo, Brazil Herpetological Journal FULL PAPER Correspondence: Henrique B. Braz (h.braz@hotmail.com) Volume 24 (January 2014), 49–57 Published by the Briish Herpetological Society Fossorial snakes have atracted litle scieniic atenion in studies of natural history, despite their relevance to capture the range of evoluionary-ecological strategies of snakes. In this study, we examined 62 preserved specimens of Phalotris laivitatus (a member of the fossorial and poorly studied Elapomorphini tribe) to obtain informaion about sexual dimorphism, reproducion, seasonal acivity and diet. Males were smaller than females but had longer tails, larger heads and were more heavy-bodied. Females atained sexual maturity at larger body sizes than males. Reproducion is seasonal in both sexes. Vitellogenesis started in mid-autumn, and peaked from late spring to summer. Oviductal eggs and oviposiion were recorded from late spring to early summer, while hatchings occurred from late summer to autumn. Clutch size was low, a recurrent trait in fossorial snakes. Spermatogenesis began in autumn, peaked during spring and tesicular quiescence occurred in summer. The ductus deferens contained sperm only in spring, when the sexual segment of the kidneys showed dense secretory granules and males were more acive. Thus, we suggest that maing is likely to occur in spring. Diet is specialised in amphisbaenids, and no evidence of ontogeneic shit was detected. This is the irst quanitaive study on the ecology of an Elapomorphini species. Key words: acivity paterns, body sizes, Elapomorphini, food habits, reproducive cycles, sexual dimorphism INTRODUCTION D etailed informaion on natural history is required for understanding paterns and processes involved in the evolution of ecological traits. For example, a description of the reproductive cycle of a number of snake taxa is required to test alternaive hypotheses on the evoluion of reproducive paterns (e.g., Almeida- Santos & Salomão, 2002; Aldridge et al., 2009). Although a large amount of data is available for several species, knowledge on snake ecology is mostly based on diurnal and terrestrial taxa. Accordingly, more secreive species such as fossorial taxa remain poorly studied with respect to their natural history. A recent study on the conservaion status of the world’s repiles highlighted this issue. While assessing the exincion risk in a representaive sample of repiles, the authors noiced a high data deiciency in tropical regions and in fossorial or semi-fossorial repiles (Böhm et al., 2013). Fossorial life may impose serious challenges to morphology and thermoregulaion (Pough, 1980; Shine, 1983). In turn, these characteristics may constrain opportuniies to feeding and strongly afect potenial reproducive output. For example, clutch size in distantly related fossorial or semi-fossorial species is oten low and eggs are usually elongated (Marques, 1996; Marques & Puorto, 1998; Balestrin & Di-Bernardo, 2005; Braz et al., 2009). Thus, the ecology of fossorial snakes is of interest per se, and more data are needed for a complete understanding of snake ecology. Elapomorphini is a monophyleic group of fossorial snakes containing nearly 48 species allocated to three genera ( Apostolepis , Elapomorphus and Phalotris ) widely distributed in South America (Ferrarezzi, 1994; Grazzioin et al., 2012; Uetz, 2013). They share several features, such as eye reducion, cylindrical body, short tail, fusion of cephalic scales, cranial reinforcement and small heads not distinct from the body, usually interpreted as specialisaions for fossorial life (Savitzky, 1983; Ferrarezzi, 1993; Harvey, 1999). Mostly because of their fossorial lifestyle, the group is poorly represented in scieniic collecions (Harvey 1999; Hofstadler-Deiques & Lema, 2005), and no quanitaive autecological study has so far been published. Food items ideniied from wild- caught individuals of Elapomorphini consisted mainly of amphisbaenids and small fossorial snakes (e.g., Lema, 1989; Zamprogno & Sazima, 1993; Ferrarezzi et al., 2005; Gomes et al., 2005; Bernarde & Macedo-Bernarde, 2006; Duarte, 2006, 2012; Hartmann et al., 2009; Mesquita et al., 2009; Barbo et al., 2011). Vitellogenic females and egg-laying were previously reported from late spring to early summer, and the clutch size is usually low, ranging from two to eight eggs (Travaglia-Cardoso et al., 2001; Leynaud, 2003; Braz et al., 2009; Barbo et al., 2011).