A diversidade de lagartos na Caatinga é mediada pelos térmitas?

Intending to explain the extraordinary lizard coexistence levels found in Australian deserts, Morton & James (1988) figured out a hypothesis which defends that the termite diversity would bring about lizard radiation. This study aims to verify the validation of that hypothesis in Caatinga lizard assemblages. This study also objectives verifying if the termite defense mechanisms influence their consuming levels by lizards and if this pattern differs between different lizard lineages. Termites were collected using a standardized sampling protocol of termites. Besides using haphazard sampling, we collect lizards with 108 pitfall traps in each area. Intending to check the linkage between the termite and lizard assemblages, the lizard stomach contents were analyzed and then a canonical correspondence analysis was performed. The presence of nonrandom patterns of diet overlap among the lizard species was also examined. Aiming to check if the defense mechanisms of termite influence their consuming pattern by lizards it was performed a laboratory experiment where termite with different defense mechanisms were offered to lizards of two different lineages. We verified that lizard assemblages do not consume termites according to termite abundance in ecosystems. Furthermore, mean niche overlap lizard species did not differ significantly from that expected by chance. We found that termite chemical defense mechanism does influence the termite s pattern consuming by lizards. These results do not corroborate premises which support Morton & James hypothesis (1988) and point out that lizard do not chose termites based on their abundance, but, trying to avoid consuming termites which exhibit chemical defense mechanisms. This defense mechanism, however, may not be the only explanation to patterns of termite s consuming by lizards.

Ecologia comportamental de tropidurus Hispidus e Tropidurus Semitaeniatus (Squamata, Tropiduridae) em Simpatria, em área de caatinga do nordeste do Brasil.

This study evaluated the spatial, time and alimentary niches of Tropidurus hispidus and Tropidurus semitaeniatus in sympatry in a caatinga of Rio Grande do Norte, Brazil, as well as their foraging and termoregulatory behaviors, the activity body temperature and their reproductive and fat body cycles. Monthly excursions, from October 2006 to May 2008, were conducted at the Ecological Station of the Seridó (ESEC Seridó), Serra Negra do Norte municipality, using specific methodology for investigation of the aforementioned objectives. The two species presented similarities in space niche use, mainly in rocky habitat, however they differed in vertical microhabitat use with T. hispidus using a larger vertical microhabitat range. In the dry season the time of activity of both species was bimodal. In the wet season T. semitaeniatus showed a unimodal activity period, while T. hispidus maintained an bimodal activity period. In terms of importance in the diet, to both species, Hymenoptera/Formicidae and Isoptera predominated during the dry season. In the wet season, although Hymenoptera/Formicidae had larger importance among the prey items, lizards opportunistically predated on Lepidoptera larvae, Coleoptera larvae/adults and Orthoptera nymphs/adults. The foraging intensity revealed differences between the species, mainly in the wet season, when T. semitaeniatus was more active than T. hispidus. The mean activity body temperature of T. semitaeniatus was significantly higher than that of T. hispidus. The thermoregulatory behavior showed that during the dry season T. hispidus and T. semitaeniatus spent more time in shade or under filtered sun. In the wet season, T. hispidus did not show differences in the amount of time spent among the light exposure locations, however T. semitaeniatus spent most of their time exposed to direct sun or filtered sun. The reproductive cicle of T. hispidus and T. semitaeniatus occurred from the middle of the dry season to the beginning of the wet season. In both species, female reproductive activity was influenced by precipitation, whereas males exhibited spermatozoa in their testes throughout the year, and their reproductive activity was not related with any of the climatic variables analysed. In the two species, the fat storage varied inversely with reproductive activity, and there was no difference in fat body mass between females and males. We concluded that the segregation between T. hispidus and T. semitaeniatus in this caatinga area occurs in vertical space use, in the largest vagility of T. hispidus in microhabitat use and larger range size of their alimentary xviii items. Additionally, significant seasonal differences in relation to the activity period, body temperature, and foraging and termoregulatory behaviors between these two Tropidurus species facilitate their coexistence.

Dieta e compotamento de forrageio de duas espécies de Tropidurus (Squamata,Tropiduridae) em uma área de Caatinga do Nordeste do Brasil

Tropidurus semitaeniatus and Tropidurus hispidus are lizard species that are widely distributed in Brazil. The former is endemic to the Caatingas, where they live in syntopy with the latter, which is distributed in other ecosystems and biomes. In this work, diet was evaluated including seasonal variations as well as foraging behavior, to determine the importance of these factors in the structure of these populations and the coexistence of these species in syntopy. No significant difference was found in diet composition between the two species, although T. hispidus feed on larger preys than do T. semitaeniatus; this fact, along with the different foraging behavior in the rainy season, are ecological factors that contribute to the syntopic coexistence of these species in the Caatinga area studied

Estrutura da Comunidade de Lagartos de um remanescente de mata atlântica do Estado do Rio Grande Do Norte, Brasil.

As part of a broader project, Diversity and Distribution Patterns of Floristic and Faunistic composition of remnants of Potiguar s Atlantic Forest, as subsidies to conservation , that subsidizes a group of institutional research, This study aimed to evaluate the structure of the assemblage of lizards a remnant of the of the northern Atlantic Forest, identifying ecological factor (s) that contribute to the coexistence of sympatric species. Additionally, we studied the thermal ecology and thermoregulatory behavior of umbrophily and heliophily species live the Parque Estadual Mata da Pipa (PEMP), a remnant of Atlantic forest located in the Tibau do Sul municipality of, Rio Grande do Norte State, Brazil. It is one of the largest remnants of the Atlantic Forest and has an area of approximately 290 ha. The study was performed by four excursions to the field for 20 days each, when active search and pitfalls traps were used to record and colleted specimens in different habitats of the area. We recorded the presence of 19 species of lizards, of which seven are typical of forest areas, three are endemic Atlantic Forest, these two northern and one are new record for the Rio Grande do Norte. The use of resources, the results showed that phylogenetically related species do not always use a similar way the resources available; the feeding niche was the segregated component of the species that overlapped extensively in the use of space and vice versa. To examine the thermal ecology and thermoregulatory behavior of Kentropyx calcarata and Coleodactylus natalensis, we recorded the clocal temperature (Tc), oh the substrate (Ts) and of the air (Ta) to investigate what of these are the source of heat more important to the temperature s body of these lizards. Behavioral observations were conducted to analyze strategies to optimize the acquisition of heat. The air temperature explained most strongly to variation in body temperature of K. calcarata, while the temperature of the substrate to C. natalensis. As for the behavioral observations, they confirmed that K. calcarata is an active thermoregulatory; C. natalensis is a passive thermoregulatory.

Ecologia alimentar e comportamento de forrageamento de Ameivula aff. ocellifera (Squamata: Teiidae) em área de caatinga do nordeste do Brasil

This study investigated the influence of intrinsic and extrinsic factors on the feeding ecology and foraging behavior of the whiptail lizard Ameivula aff. ocellifera, a new species widely distributed in the Brazilian Caatinga, and that is in process of description. In attendance to the objectives, the Dissertation was structured in two chapters, which correspond to scientific articles, one already published and the other to be submitted for publication. In Chapter 1 were analyzed the general diet composition, the relationship between lizard size and prey size, and the occurrence of sexual and ontogenetic differences in the diet. Chapter 2 contemplates a seasonal analysis of diet composition during two rainy seasons interspersed with a dry season, and the quantitative analysis of foraging behavior during two distinct periods. The diet composition was determined through stomach analysis of lizards (N = 111) collected monthly by active search, between September 2008 and August 2010, in the Estação Ecológica do Seridó (ESEC Seridó), state of Rio Grande do Norte. Foraging behavior was investigated during a rainy and a dry month of 2012 also in ESEC Seridó, by determining percent of time moving (PTM), number of movements per minute (MPM) and prey capture rate by the lizards (N = 28) during foraging. The main prey category in the diet of Ameivula aff. ocellifera was Insect larvae, followed by Orthoptera, Coleoptera and Araneae. Termites (Isoptera) were important only in numeric terms, having negligible volumetric contribution (<2%) and low frequency of occurrence, an uncommon feature among whiptail lizards. Males and females did not differ neither in diet composition nor in foraging behavior. Adults and juveniles ingested similar prey types, but differed in prey size. Maximum and minimum prey sizes were positively correlated with lizard body size, suggesting that in this population individuals experience an ontogenetic change in diet, eating larger prey items while growing, and at the same time excluding smaller ones. The diet showed significant seasonal differences; during the two rainy seasons (2009 and 2010), the predominant prey in diet were Insect larvae, Coleoptera and Orthoptera, while in the dry season the predominant prey were Insect larvae, Hemiptera, Araneae and Orthoptera. The degree of mobility of consumed prey during the rainy seasons was lower, mainly due to a greater consumption of larvae (highly sedentary prey) during these periods. Population niche breadth was higher in the dry season, confirming the theoretical prediction that when food is scarce, the diets tend to be more generalized. Considering the entire sample, Ameivula aff. ocellifera showed 61,0 ± 15,0% PTM, 2,03 ± 0,30 MPM, and captured 0,13 ± 0,14 per minute. Foraging mode was similar to that found for other whiptail lizards regarding PTM, but MPM was relatively superior. Seasonal differences were verified for PTM, which was significantly higher in the rainy season (66,4 ± 12,1) than in the dry season (51,5 ± 15,6). It is possible that this difference represents a behavioral adjustment in response to seasonal variation in the abundance and types of prey available in the environment in each season

Ecologia e história natural de população Hemidactylus agrius (Squamata: Gekkonidae) em área de Caatinga, com avaliação da distribuição das espécies nativas do gênero no nordeste do Brasil

The genus Hemidactylus Oken, 1817 has cosmopolite distribution, with three species occurring in Brazil, two of them native, H. brasilianus and H. agrius, and one exotic, H. mabouia. Considering the studies about ecology of lizards conducted in the Ecological Station of the Seridó, from 2001 to 2011, this study aimed (1) to re-evaluate the occurrence of the species of Hemidactylus in this ESEC; (2) to analyze ecological and biological aspects of the H. agrius population; and (3) to investigate the current and potential distribution of the native species of the genus in northeastern Brazil, analyzing the suitability of ESEC to this taxon. For the first two objectives, a sampling area consisting of five transects of 200 x 20 m, was inspected in alternating daily shifts for three consecutive days, from August 2012 to August 2013. For the latter objective, occurrence points of H. agrius and H. brasilianus from literature and from the database of Herpetological Collections of the UFRN and the UNICAMP were consulted to build predictive maps via the Maximum Entropy algorithm (MaxEnt). In ESEC Seridó, 62 H. agrius individuals were collected (25 females, 18 males and 19 juveniles), and two neonates were obtained from a communal nest incubated in the laboratory. No record was made for the other two species of the genus. Hemidactylus agrius demonstrated to be a nocturnal species specialized in habitats with rocky outcrops; but this species is generalist regarding microhabitat use. In the population studied, females had an average body length greater than males, and showed higher frequencies of caudal autotomy. Regarding diet, H. agrius is a moderately generalist species that consumes arthropods, especially insect larvae, Isoptera and Araneae; and vertebrates, with a case of cannibalism registered in the population. With respect to seasonal differences, only the number of food items ingested differed between seasons. The diet was similar between sexes, but ontogenetic differences were recorded for the total volume and maximum length of the food items. Significant relationships were found between lizard body/head size measurements and the maximum length of prey consumed. Cases of polydactyly and tail bifurcation were recorded in the population, with frequencies of 1.6% and 3.1%, respectively. In relation xv to the occurrence points of the native species, 27 were identified, 14 for H. agrius and 13 for H. brasilianus. The first species presented restricted distribution, while the second showed a wide distribution. In both models generated, the ESEC Seridó area showed medium to high suitability. The results of this study confirm the absence of H. brasilianus and H. mabouia this ESEC, and reveal H. agrius as a dietary opportunist and cannibal species. Further, the results confirm the distribution patterns shown by native species of Hemidactylus, and point ESEC Seridó as an area of probable occurrence for the species of the genus, the establishing of H. brasilianus and H. mabouia are probably limited by biotic factors, a fact yet little understood

Herpetofauna associada à bromélia rupícola, encholirium spectabile, no semiárido brasileiro: revisão da literatura, ecologia das espécies e comportamento de psychosaura agmosticha (squamata: mabuyidae)

Bromeliads are an important microhabitat for the herpetofauna, for being widely used as refuge from predators and their leaf architecture allows humidity maintenance and relatively constant temperature inside, setting a favorable environment for amphibians and reptiles, especially in areas under hydric stress. However, studies addressing this relationship are still incipient and more concentrated in fitotelmatas bromeliad. For non-fitotelmatas rupicolous bromeliads of the gender Encholirium, which develops into rocky outcrops and contains species of semi-arid regions such as the Caatinga, animal-plant relationships are almost unknown. In this context, this study aimed to know the herpetological fauna inhabitant of macambiras bromeliads, Encholirium spectabile, analyzing occupation and use of these bromeliads by different taxa, and the behavioral ecology of the lizard Psychosaura agmosticha, seeking to identify factors associated with this strict relationship in Caatinga. An extensive review of the world literature on the subject “lizards in bromeliads” subsidized this study from the ecological perspective of this association. The field work was carried out at Fazenda Tanques, municipality of Santa Maria / RN, mesoregion of Agreste Potiguar. The observations and/or data collection in daytime and in the evening was conducted monthly during three consecutive days, from January 2011 to August 2012, totaling 450 hour.man of sampling effort. Sixteen species were registered: six lizards (Mabuyidae, Tropiduridae, Gekkonidae and Phyllodactylidae Families), six snakes (Boidae and Dipsadidae Families) and four of amphibians of Hylidae Family. The effect of the forest edge on the distribution of species along the outcrop was significant, with most species found in outcrop edges. Significant difference was found between some pairs of species concerning use of bromeliads, and almost total niche overlap in the use of microhabitat. 62.5% of the species are nocturnal and use these plants for sheltering, breeding and feeding. Regarding the relations between 4 the lizard Psychosaura agmosticha and macambiras bromeliads, behaviors of thermoregulation and foraging in the dry and wet seasons were recorded. Activity periods were concentrated between 7 and 10 am and between 3 and 5 pm in both seasons, showing a clear bimodal pattern. The species basically used the green leaves and there were no significant differences between males and females in the use of bromeliads. Positive associations were found between body temperature and temperatures of bromeliads and air. This species spent 1.95% ± 3.8 of the time moving (PTM) and moved on average 0:36 ± 2.1 seconds per minute (MPM), with significant differences between the wet and dry to PTM, and between the average time of stop and average duration of movements, being considered a sedentary forager. Psychosaura agmosticha, in the study area, is bromelicolous and uses macambiras primarily for thermoregulation and foraging. The results of this study elevate the rupicolous bromeliads Encholirium spectabile as key elements for the maintenance of amphibians and reptiles associated with it, and a clear advantageous association for the conservation of the groups involved.

O papel dos quintais urbanos na segurança alimentar, bem estar e conservação da biodiversidade

Residential homegardens have environmental and social roles in the urban environment. These green spaces can potentially minimize the impacts caused by the growth of cities, being an alternative to connect fragmented areas or offer refuge to wildlife and therefore support the conservation of biodiversity. In addition, the homegardens demonstrate a leading role in increasing human well-being by promoting socialization opportunities, contact with nature, local culture as well as improvements in food security for the urban families. Nevertheless, it is still unclear what specific characteristics of homegardens can act effectively in the conservation of the biodiversity, as well as in the construction of food security and well being of the homegardeners and their families. The first chapter of this thesis analyzed the diversity of plant species (native and exotic) and assessed the contribution of different types of urban gardens (ornamental and forest gardens alike) in the presence of wildlife such as birds, monkeys and lizards. In the second chapter we evaluated the contribution of those gardens to the welfare and food security of their owners. In order to do this, 41 gardens were visited in Pium, a southern coastal town in the northeastern Brazil, which also happens to be in a periurban region undergoing rapid urban expansion and pressure from the real estate market. We surveyed the planned biodiversity and fauna associated with homegardens. The data related to food security and welfare were sampled through interviews with the person in charge of taking care of the gardens. These interviews covered issues on the supply of food from the garden and absence of chemical products, as well as aspects of the GNH indicator (Gross National Happiness). The results showed that these homegardens generally contribute little to the maintenance of native plant species (native species = 29/ total = 187). From its main features, the gardens were classified as ornamental, forest gardens and forest farms. These groups had a different effect on the presence of the animals studied and the last two contained most of the sampled native species. The diversity of plants and trees was a good predictor of the presence of birds and monkeys. Thus, the contribution of yards for the conservation of biodiversity depends on the type of garden: some even can have negative effects on conservation. These results can direct new approaches to detailed understanding of gardens and also of public policies applied to urban planning. The results of the second chapter showed that the two types of forest gardens contributed to household food security, for providing food and medicinal herbs, which mostly did not have pesticides and chemical 12 fertilizers. But the three groups of gardens are important components for the well being of their stakeholders. Gardens help promote the transmission of knowledge on agriculture, socialization, contact with nature and bring up feelings related to peace and harmony. Thus, forest gardens can be considered important means to get through public projects and policies designed to encourage biodiversity and promote food security and well-being in urban areas

Ecologia trófica de uma comunidade de lagartos da caatinga

The trophic ecology studies issues related to the diet of individuals within a community .The relation between the body size of the predator and the prey size, individual specialization and niche breadth are some of the issues that can be discussed by it .I collected the lizards using pitfall trap, glue and active collecting traps in a fragment of Caatinga. The most common species in this community were Tropidurus hispidus, T. semitaeniatus and Cnemidophorus ocellifer. The visits to the farm also relied on collecting invertebrates at each season to understand how the nutritional resources of lizards were presented in each one of them. I tried to answer some questions : 1) If there was a positive relation between body size of the predator and the size of prey of the community ; 2) If in different seasons the relation of body size of the predator and the maximum and/or minimum size of the prey would be positive ; 3) If species with different foraging strategies have positive relation on the size of the predatorprey relation; 4) If the seasonality would influence on the individual expertise of lizards community and more common species; 5) If the breadth of the niche would be influenced by seasonality ; 6) If more individuals with different morphology between them would present less similar diet. I found that there was indeed a positive relationship between size of prey and predator, but nonexistent related to the minimum size of prey; Among the seasons relative size of predators and prey was different for the maximum and minimum size, but was positively related only to the size of the maximum prey. And comparisons between different foraging strategies had the maximum and minimum line inclination greater than zero and different from each other; individual specialization was not influenced by seasonality and the niche breadth was wider in the dry season only to T. semitaeniatus. At last I didn't find a significant negative relationship between morphological dissimilarity and similarity of diet.