Neotropical Biology and Conservation 10(2):63-73, may-august 2015 © 2015 by Unisinos - doi: 10.4013/nbc.2015.102.02 Structure of a Caatinga anuran assemblage in Northeastern Brazil Estrutura de uma Taxocenose de Anuros no Nordeste do Brasil Edinaldo Leite Filho1 [email protected] Abstract Based on data on diet and microhabitat use, we investigated the importance of current Washington Luiz da Silva (ecological) and historical factors (phylogenetic) in the organization of an anuran assem- Vieira2 blage in temporary ponds in a Caatinga area in Northeastern Brazil. The objective of this [email protected] study was to verify how diet and microhabitat use influence the community structure, and 2 their determinants. Niche breadth based on microhabitat use was relatively low for all Gindomar Gomes Santana species; thus, we also observed a spatial segregation between Hylidae and other families. [email protected] The closely related species exhibit a more similar diet; the main prey categories used by Felipe Jardelino Eloi1 Caatinga anurans were Coleoptera, insect larvae and Formicidae. The pseudo-community [email protected] analysis based on diet and microhabitat use revealed that the observed niche overlap did not differ statistically from random, indicating a lack of detectable competition for these Daniel Oliveira Mesquita1 resources. The Canonical Phylogenetic Ordination (CPO) analyses revealed no significant [email protected] phylogenetic effect on the assemblage, neither for diet nor for microhabitat use. Results suggest that predation and hydroperiod may be the most important factors in determining assemblage patterns, but more studies are needed to support this hypothesis. Keywords: community, Amphibia, ecological factors, historical factors. Resumo Com base em dados da dieta e uso de microhabitat, investigamos os fatores atuais (eco- lógicos) e históricos (filogenéticos) na organização de uma taxocenose de anuros de po- ças temporárias em uma área de Caatinga no Brasil. O objetivo desse estudo consistiu em verificar como a dieta e o uso de microhabitat influenciam a estrutura da comunidade, assim como suas determinantes. A amplitude de nicho no uso de microhabitat foi relati- vamente baixa para todas as espécies. Todavia, observou-se uma segregação espacial entre a família Hylidae e as demais. As principais categorias alimentares foram Coleop- tera, larvas de Insecta e Formicidae. Espécies filogeneticamente próximas apresentaram dieta similar. A análise de pseudocomunidades revelou que as diferenças para os valores de dieta e uso de microhabitat não são significativas, indicando ausência de competição por esses recursos. A análise de ordenação canônica não detectou efeito significativo da 1 Departamento de Sistemática e Ecologia, Universidade filogenia para dieta e uso de microhabitat. Os resultados sugerem que o hidroperíodo e a Federal da Paraíba. Cidade Universitária, 58059-970, João predação podem ser os fatores mais importantes na determinação dos padrões da taxo- Pessoa, PB, Brazil. cenose, porém, mais estudos são necessários para sustentar essa hipótese. 2 Laboratório de Ecofisiologia Animal, Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba. Cidade Universitária, 58059-970, João Pessoa, PB, Brazil. Palavras-chave: comunidade, Amphibia, fatores ecológicos, fatores históricos. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits reproduction, adaptation, and distribution provided the original author and source are credited. Edinaldo Leite Filho, Washington Luiz da Silva Vieira, Gindomar G. Santana, Felipe J. Eloi, Daniel O. Mesquita Introduction finding a positive correlation among Material and methods prey and body size and anuran mouth Assemblage structure can be defined width. In an anuran assemblage in the Study site as a non-randomized use of resources Cerrado of central Brazil, a significant by coexisting individuals (Begon et relationship was found between phy- Field surveys were conducted from al., 2007; Ricklefs, 2010; Ricklefs logeny and interspecific synchrony March 2008 to April 2010 at the Es- and Miller, 1999). The knowledge (Bini et al., 2003). However, the vast tação Experimental de São João do of resource use patterns by coexist- majority of studies did not take into Cariri – EESJC (07° 25’ S, 36° 30’ W), ing species is vital for understanding account the influence of the evolu- and at Fazenda Olho D’água (07° 22’ ecological systems, once it provides tionary history of species. S, 36° 31’ W), near São João do Cariri information about competitive in- The Caatinga Biome comprises a de- municipality, in the central part of teractions among species (Pianka, cidual dry environment (see Leal et Paraíba state. The altitude ranges be- 1986; Winemiller and Pianka, 1990). al., 2005), covering an area of 734,478 tween 450 and 550 m above sea level Previously, competition was consid- km² (MMA, 2002) and harbours a and the mean temperature from 28° to ered as a primary structuring assem- great diversity of environments with 35° C. Both sites have a shallow and blage mechanism (MacArthur et al., its typical vegetation type located in rocky soil with many rocky outcrops. 1972). Physical disturbance, preda- the “Depressão Sertaneja” (Velloso Soils are composed mainly by sand or tion and parasitism were also consid- et al., 2002). The Cariri region from clay, having moderate permeation ca- ered important (Diamond and Case, Paraíba State is considered one of the pacity and water retention. Vegetation 1986; Hudson and Greenman, 1998). driest Brazilian areas, with annual av- is composed of dispersed shrubs with More recently, special attention has erage temperatures around 25 °C with some evenly distributed trees, which been given to the evolutionary his- unequally distributed average rainfall can reach ten meters height. There is a tory of species, supposing that many of 350 mm per year (Cabral, 1997). high density of cacti and bromeliads, characteristics of the current species Most studies on the Caatinga herpeto- as well as temporary ponds, during the are simply the result of phylogenetic fauna are restricted to checklists or rainy season (Vieira et al., 2007). conservatism (Cavender-Bares et al., species descriptions. Arzabe (1999) 2009; Ernst et al., 2012; Losos 2008). studied two anuran assemblages in Sampling methods Finally, ecological and phylogenetic different altitude areas, observing how factors may be important for deter- environmental characteristics promote Based on a previous study (see Vieira, mining the current patterns of assem- differences in assemblage organiza- 2006), we chose five temporary ponds blages (Cavender-Bares et al., 2009; tion. Vieira et al. (2007) examined the as sampling sites; in each site, we Ernst et al., 2012; Eterovick et al., spatial and temporal distribution of an measured size and maximum depth 2010; Losos, 2008; Mesquita et al., anuran assemblage associated with (Table 1). Monthly samplings were 2006; Mesquita et al., 2007; Webb et temporary ponds in Cariri from Paraí- carried out from March 2008 to April al., 2002; Wiens et al., 2011). ba State, and noticed that environment 2010, however, we only registered an- Some studies with anuran assemblag- heterogeneity and hydroperiod affect uran activity during the rainy season es have been performed in the Neo- the assemblage dynamics, and Pro- (March to June 2008; January to April tropical region in the last 30 years. tázio et al. (2015) has recently found 2009 and 2010), when ponds keep Toft (1980, 1981) conducted pioneer- historical influence on microhabitat surface water and males were call- ing studies on anuran assemblages use for hylids and Leptodactyliformes ing, totalizing 58 hours of search. The in tropical forests from Panama and in temporary ponds in Caatinga, al- amphibians were sampled throughout Peru, investigating diet patterns and though their results suggest that eco- visual transects and auditory search foraging mode, suggesting that these logical factors such as competition are procedures (Crump and Scott Jr, species could be classified as ant spe- more apparent in anuran assemblages. 1994) between 19h and 24h. Visual cialists, not-ant specialists and gener- In order to increase the knowledge surveys consisted of walking a com- alists. Santos et al. (2004), studying about the amphibian ecology and plete lap along the shore of the pond, the feeding habits of six frog species natural history in the Caatinga, the searching for potential microhabitats in an Atlantic Forest fragment, identi- objective of this study was to verify used by anurans at a distance about fied that most species behave as gen- how the diet and microhabitat use in- five meters from the pond, during ap- eralists and there was a slightly great- fluence the community structure, and proximately 30 to 50 minutes in each er niche breadth in the rainy season. their determinants. We also test for pond. On each field trip, the sequence López et al. (2005) evaluated the diet Phylogenetic effects in anuran assem- of the sampled ponds was random- niche overlap among nine Leptodac- blage from the Cariri region, Paraíba ized and all the individuals collected tylidae species in western Argentina, State, Brazil. were registered. The individuals were 64 Volume 10 number 2 may - august 2015 Structure of a Caatinga anuran assemblage in Northeastern Brazil Table 1. Characterization of temporary ponds during the survey period in São João do albifrons, L. fuscus and P. nordestina). Cariri, Paraíba State, northeastern Brazil. To evaluate food availability in the environment, we used 10 pitfalls (300 2 Ponds Coordinates Area (m ) Max. Profundity (cm) ml plastic cups) and 2 window traps 1 07º22’53’’S, 36º31’50’’W 3,000 26 disposed randomly, near to the ponds, 2 07º22’52’’S, 36º31’51’’W 3,693.6 28.4 covering all microhabitats. The traps 3 07º22’50’’S, 36º31’49’’W 15,622 75 were revised daily, during the field 4 07º22’49’’S, 36º31’46’’W 11,345.7 36 trips. The invertebrates collected were 5 07º22’45’’S, 36º31’50’’W 113.0 44.5 preserved in ethanol 70%.