Cássio de Carvalho Batista

Bio: Cássio de Carvalho Batista is an academic researcher. The author has contributed to research in topics: Ecological niche & Leptodactylus mystacinus. The author has an hindex of 3, co-authored 3 publications receiving 63 citations.

Diet of Rhinella schneideri (Werner, 1894) (Anura: Bufonidae) in the Cerrado, Central Brazil.

Abstract: This study describes the diet of Rhinella schneideri based on the analysis of the stomach contents of 18 specimens from an area within the Cerrado, Central Brazil. We found 842 items belonging to 11 prey categories, including the plant material category. The most important prey categories for R. schneideri were Insect larvae, Coleopteran and Formicidae. Numerical and volumetric niche breadths of R. schneideri were 3.35 and 1.00, respectively. According to its diverse diet and abundance, R. schneideri may be considered a generalist and opportunist species.

História natural de Leptodactylus mystacinus e Leptodactylus fuscus (Anura: Leptodactylidae) no Cerrado do Brasil Central

Abstract: Aspects of the ecology of Leptodactylus mystacinus and Leptodactylus fuscus were investigated in an area of the Cerrado of Central Brazil The study included use of microhabitat, activity patterns, diet and, morphometry Observations were conducted between April, 2006, and February, 2007 The species are sexually dimorphic - females larger than males - and body size in L mystacinus is larger than that of L fuscus Both species preferred the ground surface (microhabitat) of wetland habitats with herbaceous vegetation close to lentic water bodies Leptodactylus mystacinus was observed most often in October and November (8:00-8:59 PM and 11:00-11:59 PM), and L fuscus in November and October between 7:00 PM and 8:59 PM The diet of both populations was based on Arthropoda, primarily Coleoptera, which was the most important order (IVI) Differences in the volumetric proportions of the categories of then preys used, and in the periods when they were most observed, are probably the factors that contribute the most to the coexistence of both species in the area Intersexual differences in the diet were observed in both species These differences were probably associated with the differential allocation of resources to the production of gametes or occasional differences in the use of space by the two sexes

Nicho ecológico e aspectos da história natural de Phyllomedusa azurea (Anura: Hylidae, Phyllomedusinae) no Cerrado do Brasil Central

Abstract: Aspects of the ecology and natural history of Phyllomedusa azurea were investigated in an area of Central Brazilian Cerrado between April, 2006, and February, 2007. Observations were conducted between 6:00 PM and 5:00 AM. The study focused on spatial, temporal, and trophic niches, morphometry and reproduction. Most animals were recorded vocalizing in places dominated by herbaceous vegetation and an open canopy. The main substrates used were bushes and trees, and animals were seen perched most often between 0.5 and 1.0 m of height. Spatial niche breadth was 2.91 and 3.83 for substrate and perch height, respectively. Most animal were sighted close to lentic water bodies, usually up to 0.50 m. It is possible that these characteristics are related primarily to the phylogeny of the genus and secondarily to the specific needs of the species and the local availability of resources. The bushes and trees were used by the species mainly as sites of vocalization and oviposition. Specimens of Phyllomedusa azurea was sighted most frequently between 8:00 PM and 9:00 PM. Estimated temporal niche breadth (activity period) was 4.68. Prolonged reproductive pattern was also observed predominantly in the months with higher temperature and higher humidity (September to February). The diet consisted of eleven items. The most important prey taxon for the females was Orthoptera (IVI = 63), whereas for the males, it was Araneae (IVI = 33). The breadths numeric and volumetric of the trophic niche, was respectively 1.80 and 1.16, for females, and 4.03 and 3.92, for males. Males and females differed in size (SVL) and mass, with the females being larger and heavier. The sizes of smaller reproductive individuals males and females were 34.64 and 40.33 mm, respectively. Differences in size may be related to different investments in reproduction by the two sexes.

Drivers of individual niche variation in coexisting species

Abstract: Although neglected by classic niche theory, individual variation is now recognized as a prevalent phenomenon in nature with evolutionary and ecological relevance. Recent theory suggests that differences in individual variation across competitors can affect species coexistence and community patterns. However, the degree of individual variation is flexible across wild populations and we still know little about the ecological drivers of this variation across populations of single species and, especially, across coexisting species. Here, we aimed to (a) elucidate the major drivers of individual niche variation in natural communities and (b) to determine how consistent this variation is across coexisting species and communities. We analysed natural patterns of individual-level niche variation in four species of coexisting generalist frogs across a wide range of tropical communities. Specifically, we used gut contents and stable isotopes (δ13 C and δ15 N) from frog species and their prey to quantify individual niche specialization. Then, we combined data on local community structure, availability of prey, phylogenetic relationships and predator-prey size models to test how this variation is related to four ecological factors which are predicted to be key drivers of individual specialization: intraspecific competition, interspecific competition, ecological opportunity (i.e., diversity of resources) and predation. We found that the degree of individual trophic specialization varied by up to ninefold across populations within the same species. This sizable variation in trophic specialization across populations was at least partially explained by gradients of density of competitors (both conspecifics and heterospecifics) and intraguild predation. However, the specific relationships between individual specialization and these ecological gradients were strongly species-specific. As consequences, the identity of the species with more individual variation changed among sites and there was typically no spatial correlation in the degree of individual specialization across coexisting species. Our results show that individual niche specialization within and across species can be strongly context-dependent and that hierarchies of individual variation among coexisting species are not necessarily consistent across communities. Recent theory suggests that this pattern could lead to concurrent changes in competitive interactions across sites and thereby could play a key role in species coexistence at the landscape level. Our results suggest that individual variation across and within coexisting species has the potential to affect not only species coexistence at local communities, but also regional diversity patterns.

Diet of Rhinella schneideri (Werner, 1894) (Anura: Bufonidae) in the Cerrado, Central Brazil.

Abstract: This study describes the diet of Rhinella schneideri based on the analysis of the stomach contents of 18 specimens from an area within the Cerrado, Central Brazil. We found 842 items belonging to 11 prey categories, including the plant material category. The most important prey categories for R. schneideri were Insect larvae, Coleopteran and Formicidae. Numerical and volumetric niche breadths of R. schneideri were 3.35 and 1.00, respectively. According to its diverse diet and abundance, R. schneideri may be considered a generalist and opportunist species.

Diet of two sympatric Phyllomedusa (Anura: Hylidae) species from a cacao plantation in southern Bahia, Brazil

Abstract: Abstact. We studied the diet of two sympatric species of leaf-frogs, Phyllomedusa rohdei and P. burmeisteri, captured in a cacao plantation in the Atlantic forest domain of southern Bahia, using stomach-flushing. The most important prey categories for P. rohdei were Araneae, larval Lepidoptera and Orthoptera, while for P. burmeisteri: Araneae, Coleoptera and larval Lepidoptera. Other items frequently flushed out of the frogs were plant remains, mites and skin. The snout-vent-length of the frogs was not correlated with the length and number of prey items. Our results suggest that both leaf frog species studied are opportunistic sit-and-wait predators with a high overlap in prey categories.

Diet of Leptodactylus fuscus (Amphibia: Anura: Leptodactylidae) in the Pantanal of Miranda river, Brazil

Abstract: Amphibians are usually generalist predators, and their diet is influenced by extrinsic (e.g. food availability) and intrinsic factors (e.g. body size and skull shape). This study aims to describe the diet of adult males and females of Leptodactylus fuscus in the Pantanal of the Miranda river and to answer the following questions: i) Are prey's maximum size and number of food items explained by the anuran's body size? ii) Are richness of morphospecies and number of food items explained by frog sex? iii) Is there diet overlap between male and female? We recorded 62 food items, belonging to seven orders of Arthropoda, and one individual of Annelida. The diet of L. fuscus was dominated by Orthoptera, followed by Coleoptera, Araneae, Hymenoptera, Blattaria, Hemiptera and Diptera. Frog's body size did not influence prey size or number of food items consumed. The number of prey and richness of morphospecies did not differ between males and females. There was low diet overlap between the sexes. Our results provide evidence for the opportunistic and generalist feeding behavior of L. fuscus.