Journal of Herpetology , Vol. 49, No. 2, 237–244, 2015 Copyright 2015 Society for the Study of Amphibians and Reptiles Ecology of the Skink, Mabuya arajara Rebou ¸ cas-Spieker, 1981, in the Araripe Plateau, Northeastern Brazil SAMUEL C. RIBEIRO, 1,5,6 DIEGO A. TELES, 2 DANIEL O. MESQUITA, 1 WALTE ´ CIO O. ALMEIDA, 2,3 LUCIANO A. DOS ANJOS, 4 AND MIRIAM C. GUARNIERI 4 1 Programa de P ´ os-Gradua ¸ ca ˜o em Ci ˆ encias Biol ´ ogicas, Departamento de Sistema ´tica e Ecologia, Universidade Federal da Paraı ´ba – UFPB, Joa ˜o Pessoa, Paraı ´ba, Brazil 2 Programa de P ´ os-Gradua ¸ ca ˜o em Bioprospec ¸ ca ˜o Molecular, Universidade Regional do Cariri – URCA, Crato, Ceara ´, Brazil 3 Departamento de Quı ´mica Biol ´ ogica, Universidade Regional do Cariri – URCA, Crato, Ceara ´, Brazil 4 UNESP – Univ. Estadual Paulista, Campus de Ilha Solteira, Faculdade de Engenharia de Ilha Solteira, Departamento de Biologia e Zootecnia, Ilha Solteira, Sa ˜o Paulo, Brazil 5 Programa de P ´ os-Gradua ¸ ca ˜o em Biologia Animal, Laborat ´ orio de Animais Pe ¸ conhentos e Toxinas, Universidade Federal do Pernambuco – UFPE, Departamento de Zoologia, Recife, Pernambuco, Brazil ABSTRACT.—We studied diet, reproduction, and sexual dimorphism in Mabuya arajara (Arajara Skink; Scincidae) in a rainforest on the slopes of the Araripe Plateau, northeastern Brazil. Diet was composed mainly of arthropods, mostly termites, when considering both number (93.5%, n = 58) and volume (58.5%, n = 58). Mabuya arajara can be classified as a forager that uses intermediate foraging techniques, as do most of its congeners. Brood size of M. arajara ranged from two to nine neonates (4.8 6 1.7), and larger females tended to produce larger broods. The period of parturition occurs between October and December. Adult females of M. arajara were larger and heavier than adult males. There was no significant difference between the body size of males and females, but there was a significant difference in body shape between sexes. The positive relationship between brood size and female size can be considered an important correlate of the sexual selection of bigger females in Mabuya and other South American lizards in general. Several aspects of the ecology of lizards of the genus Mabuya have proven phylogenetically conservative (e.g., Vrcibradic and Rocha, 1998a,b, 2011). Species of Mabuya present similarities in many aspects of their life history, such as reproductive activity, which is characterized by similar offspring size, similar significant influence of female dimensions on clutch size, and similar long gestation periods with high energy expenditure (e.g., Vitt and Blackburn, 1983, 1991; Vrcibradic and Rocha, 1998b; Rocha and Vrcibradic, 1999). In relation to diet, these are generalist animals that consume small amounts of plant material and have a diet composition indicative of a type of foraging intermediate between typical active and typical sit- and-wait foraging (e.g., Vitt and Blackburn, 1991; Vrcibradic and Rocha, 1995). These animals also present similar average body temperatures, usually with environmental temperatures exerting a significant influence (e.g., Vrcibradic and Rocha, 1995, 1998a). For nearly 3 decades, Mabuya arajara was regarded as endemic to the southern part of the state of Ceara ´ on the Araripe Plateau in northeastern Brazil (Rebou ¸ cas-Spieker, 1981). Since then, Roberto and Loebmann (2010) have recorded this species in other mesic enclaves (‘brejos-de-altitude’) of the northern part of Ceara ´ : Ubajara National Park and the Ibiapada, Ubatuba, and Almas mountain ranges. Roberto et al. (2012) furthermore recorded the occurrence of M. arajara in the State of Piauı ´. Mabuya arajara is morphologically similar to Mabuya nigropuntacta (Black-spotted Skink), which is widely distributed in the forest regions of northern, northeastern, and central Brazil ( ´ Avila-Pires, 1995). Both species, M. arajara and M. nigropuntacta, are grouped within the arajara/nigropuntacta complex character- ized by large body size, paired frontoparietals, and no vertebral stripes (Rodrigues, 2000). Various aspects of the life history of M. nigropuntacta have been studied (Vitt and Blackburn, 1991; ´ Avila-Pires, 1995; Vitt et al., 1997) and so with other congeners (Vitt, 1991, 1995; Vrcibradic and Rocha, 1996, 1998a,b; Ramı ´rez-Pinilla et al., 2002). However, published information about M. arajara has appeared only recently, such as the observation of the parturition of a female in captivity (Roberto and Loebmann, 2010), thanatosis defensive behavior (Ribeiro et al., 2010), pulmonary infection by pentastomids (Ribeiro et al., 2012a), and geographic distribution (Ribeiro et al., 2012b; Roberto et al., 2012). The understanding of the ecology of populations of closely related species is recognized as an invaluable contribution to the conservation of M. arajara, particularly because of the increase in information on the different degrees of conservatism of life history patterns in lizards (Bogert 1949; Cooper, 1994). In this sense, we studied the ecology of M. arajara and provided a comparison with congeners, seeking to answer the following questions: 1) What is the reproductive period and mean brood size? 2) Are there differences in energy expenditure regarding reproduction between the sexes? 3) What is the effect of female size on brood size? 4) Is there sexual dimorphism in size and body shape? 5) What is the influence of lizard body size on diet composition? MATERIAL AND METHODS Study Area.—This study was conducted between September 2009 and July 2010. Collecting excursions occurred bimonthly on the slopes of the Araripe Plateau, each one lasting 10 consecutive days, at sites located in Crato (07815 0 19 00 S, 39828 0 13 00 W, site one; and 07816 0 50 00 S, 39826 0 18 00 W, site two) and Barbalha Municipal- ities (07821 0 49 00 S, 39817 0 51 00 W, site one; and 07858 0 19 00 S, 39824 0 38 00 W, site two), state of Ceara ´, northeastern Brazil. The study areas are located within the boundaries of the Environ- mental Protection Area of Araripe-APA Araripe. This forest enclave, along with all forest enclaves in the Caatinga Biome which are related to slopes of hills, is known as ‘brejos-de- 6 Corresponding Author. E-mail: ribeiroherpeto@gmail.com DOI: 10.1670/13-018