Please cite this article in press as: Lira, A.F.A., et al., Spatio-temporal microhabitat use by two co-occurring species of scorpions in Atlantic rainforest in Brazil. Zoology (2013), http://dx.doi.org/10.1016/j.zool.2013.01.002 ARTICLE IN PRESS G Model ZOOL-25341; No. of Pages 4 Zoology xxx (2013) xxx–xxx Contents lists available at SciVerse ScienceDirect Zoology journa l h om epa ge: www.elsevier.com/locate/zool Spatio-temporal microhabitat use by two co-occurring species of scorpions in Atlantic rainforest in Brazil André F.A. Lira ∗ , Adriano M. Souza, Arthur A.C. Silva Filho, Cleide M.R. Albuquerque Departamento de Zoologia, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Rua Prof. Moraes Rego S/N, Cidade Universitária, 50670-420 Recife, Pernambuco, Brazil a r t i c l e i n f o Article history: Received 1 July 2012 Received in revised form 5 January 2013 Accepted 21 January 2013 Available online xxx Keywords: Tityus pusillus Ananteris mauryi Coexistence Habitat preference Population structure a b s t r a c t With the increasing devastation of the tropical rain forest, there is a critical need to understand how animal forest communities are structured and how habitat degradation will affect these communities. We conducted a field survey to investigate the microhabitat preferences of two co-occurring species of scorpions (Tityus pusillus and Ananteris mauryi) in a fragment of Atlantic rainforest, as well as their abun- dance and their ecological niche, during both the dry and rainy seasons. Behavioural aspects related to the use of the environment and the proportions of juveniles and adults are also described. The occurrence of intra- and interspecific coexistence was assessed by active search. In addition, pitfall catches were used to assess the structure of the population in the dry and rainy seasons. The differential patterns of spatial distribution in the litter layers provided evidence of partial niche partitioning between the two coexisting scorpion species depending on age and climatic conditions. Abundance, foraging behaviour and age structure (juveniles and adults) were seasonally influenced. We conclude that the diverse and subtle behaviours involved in interaction and habitat use may facilitate species coexistence. Resource partitioning and refuge sharing on a temporal and/or spatial scale, as well as predation pressure, may drive the dynamics and spatial distribution of scorpion species in the rain forest environment. © 2013 Elsevier GmbH. All rights reserved. 1. Introduction Although habitat selection and species interactions are major factors that influence animal population dynamics (Gagnon et al., 2011; Schowalter, 2012), the features that affect such parameters are not fully understood for the majority of arthropod species. The processes involved in habitat selection usually involve responses to environmental conditions that promote growth, survival and reproductive success (Uetz, 1979; Polis, 1981; Schowalter, 2012). Therefore, the presence of conspecifics and heterospecifics in the environment will most likely result in substantial competition for the resources of food and shelter and may decisively influence habitat selection (Polis and McCormick, 1987; Kaltsas et al., 2009; Lankau, 2011). Scorpions are primarily solitary and sedentary arthropods and live preferentially in microhabitats that are colonised by other arthropods on which they prey (Brownell and Polis, 2001). Intra- and heterospecific coexistence has been recorded in several species of scorpions (Shivashankar, 1994; Warburg, 2000; Kaltsas et al., 2009) and produces different levels of sociability and aggregation. Species may either co-occur in the same habitat (environment) ∗ Corresponding author. Tel.: +55 81 96654334. E-mail address: sargametal@hotmail.com (A.F.A. Lira). or co-occur in the same shelter (niche) (Warburg, 2000). Age and seasonality have been shown to be important factors affecting such interactions (Polis, 1980a; Warburg, 2000; Kaltsas et al., 2009). The coexistence of specimens of Mesobuthus gibbosus (Brullé, 1832) in Greece, for example, was more often observed among adults on the one hand and among immature individuals on the other hand. The occasional cohabitation of mature and immature scorpions was only observed during the winter (Kaltsas et al., 2009). Simi- larly, Hottentotta judaicus (Simon, 1872) and Compsobuthus werneri judaicus (Birula, 1908), which colonised the same microhabitat in the Mediterranean region of northern Israel, shared the same shelter more frequently during the rainy season, whereas Nebo hierichonticus (Simon, 1872) and Scorpio maurus fuscus (Linneaus, 1758) cohabitated more often during the dry season (Warburg, 2000). These scorpions are species of the sand desert or the Mediterranean region, and only a few studies have addressed the ecology of scorpions occurring in tropical forests. This lack of previ- ous studies is particularly surprising in view of the high biodiversity of such environments and the evidence that environmental change is transforming the ecology of tropical forests (Lewis et al., 2009). The Brazilian Atlantic Forest is considered a hotspot of biodi- versity and features a habitat that is one of the richest in animal species and has one of the highest rates of endemism in the world (Ribeiro et al., 2009). Nevertheless, ecological studies of scorpions in such environments are rare (Dias et al., 2006; Yamaguti and 0944-2006/$ – see front matter © 2013 Elsevier GmbH. All rights reserved. http://dx.doi.org/10.1016/j.zool.2013.01.002