Sobreposição de nicho e partilha de recursos entre cinco espécies simpátricas de bufonídeos (Anura, Bufonidae) do nordeste da Argentina

The niche overlap and resource partitioning were analyzed for five sympatric bufonids from Northeastern Argentina: Rhinella schneideri, R. bergi, R. fernandezae, R. granulosa, and Melanophryniscus cupreuscapularis. The primary objectives were to analyze the diet and pattern of coexistence relative to the microhabitats among species. The bufonids, which are primarily terrestrial, exhibited a preference for small, hard prey such as formicids or coleopterans. The smallest species preferably consumed ants, while R. schneideri preferred beetles. Significant differences were detected for the diets of these five species. In addition, significant overlap in the trophic niche was noted for all species except between R. granulosa and R. schneideri. Studying the diet behaviors and trophic parameters of sympatric species provides important data for understanding the community and for the development of conservation guidelines.Analisamos a sobreposição de nicho e a partilha de recursos entre cinco cinco espécies simpátricas de bufonídeos do nordeste da Argentina: Rhinella schneideri, R. bergi, R. fernandezae, R. granulosa e Melanophryniscus cupreuscapularis. O principal objetivo foi analisar a dieta e o padrão de coexistência entre as espécies em relação aos micro-habitats. Os bufonídeos, primariamente terrestres, mostraram preferência por presas duras e de pequeno porte, como formigas e coleópteros. As espécies menores consumiram preferencialmente formigas, enquanto R. schneideri preferiu besouros. Foram detectadas diferenças significativas entre as dietas das cinco espécies. Além disso, houve sobreposição significativa entre os nichos tróficos de todas as espécies, exceto entre R. granulosa e R. schneideri. O estudo do comportamento alimentar e dos parâmetros tróficos de espécies simpátricas fornece dados importantes para a compreensão da estrutura das comunidades e para o delineamento de estratégias de conservação.Fil: Duré Pitteri, Marta Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Kehr, Arturo Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Schaefer, Eduardo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

Diversity of amphibians in rice fields from northeastern Argentina

Se registró y analizó la diversidad y riqueza de una comunidad de anfibios que habita campos de arroz en el nordeste de Ar.gentina. Las muestras fueron obtenidas en el período comprendido entre octubre 2001 y junio 2003. Se identificaron 26 especies habitando cinco microhábitats: campos de arroz, zanjas y caminos, vegetación natural, vegetación acuática y barrancas. La vegetación natural fue el microhábitat más diverso mientras que las barrancas presentaron la menor cantidad de especies. El modelo de rango abundancia serie logarítmica fue el de mejor ajuste para tres de los microhábitats analizados, otro se ajustó al modelo geométrico y el restante al modelo de varilla rota. Los datos sugieren que los cultivos de arroz del nordeste argentino, podrían albergar una fauna muy diversa si están sujetos a un manejo apropiado.Registrou-se e analisou-se a diversidade e riqueza de uma comunidade de anfíbios que habita campos de arroz no nordeste da Argentina. As amostras foram obtidas no período compreendido entre outubro de 2001 e junho de 2003. Identificaram-se 26 espécies habitando cinco microhábitats: campos de arroz, sulcos e caminhos, vegetação natural, vegetação aquática e barrancas. A vegetação natural foi o microhábitat mais diverso enquanto que as barrancas apresentaram a menor quantidade de espécies. O modelo de espécie-abundância de série logarítmica foi o de melhor ajuste para três dos microhábitats analisados, outro foi ajustou ao modelo geométrico e o último ao modelo de vara quebrada. Os dados sugerem que os cultivos de arroz do nordeste argentino poderiam abrigar uma fauna muito diversa se estão sujeitos a uma manipulação apropriada.The anuran biodiversity and richness of a frog community inhabiting rice fields in northeastern Argentina was surveyed and analyzed. The samples were taken between October 2001 and June 2003. Twenty six species of amphibians were identified in five microhabitats: rice fields per se, ditches and paths, natural vegetation, aquatic vegetation and gullies. The natural vegetation was the most diverse of the microhabitats, while gullies were the poorest in species. The amphibian species of three of the microhabitats adjusted to the logarithmic range-abundance model, one to the geometric and one to the broken stick model. The data suggest that rice cropping in northeastern Argentina, if properly managed, can support a diverse anuran fauna.Fil: Duré Pitteri, Marta Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Kehr, Arturo Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Schaefer, Eduardo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Marangoni, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

Niche overlap and resource partitioning among five sympatric bufonids (Anura, Bufonidae) from northeastern Argentina

The niche overlap and resource partitioning were analyzed for five sympatric bufonids from Northeastern Argentina: Rhinella schneideri, R. bergi, R. fernandezae, R. granulosa, and Melanophryniscus cupreuscapularis. The primary objectives were to analyze the diet and pattern of coexistence relative to the microhabitats among species. The bufonids, which are primarily terrestrial, exhibited a preference for small, hard prey such as formicids or coleopterans. The smallest species preferably consumed ants, while R. schneideri preferred beetles. Significant differences were detected for the diets of these five species. In addition, significant overlap in the trophic niche was noted for all species except between R. granulosa and R. schneideri. Studying the diet behaviors and trophic parameters of sympatric species provides important data for understanding the community and for the development of conservation guidelines.Analisamos a sobreposição de nicho e a partilha de recursos entre cinco cinco espécies simpátricas de bufonídeos do nordeste da Argentina: Rhinella schneideri, R. bergi, R. fernandezae, R. granulosa e Melanophryniscus cupreuscapularis. O principal objetivo foi analisar a dieta e o padrão de coexistência entre as espécies em relação aos micro-habitats. Os bufonídeos, primariamente terrestres, mostraram preferência por presas duras e de pequeno porte, como formigas e coleópteros. As espécies menores consumiram preferencialmente formigas, enquanto R. schneideri preferiu besouros. Foram detectadas diferenças significativas entre as dietas das cinco espécies. Além dis-so, houve sobreposição significativa entre os nichos tróficos de todas as espécies, exceto entre R. granulosa e R. schneideri. O estudo do comportamento alimentar e dos parâmetros tróficos de espécies simpátricas fornece dados importantes para a compreensão da estrutura das comunidades e para o delineamento de estratégias de conservação

Anurans trophic dynamic and guild structure in tropical dry forests of the Caribbean region of Colombia

Studies on the exploitation of trophic resources allow to establish interactions between predators and predator-prey, and this dynamic can present fl uctuations over time and space. We analysed stomach contents of 19 anuran species from tropical dry forests of Colombia, quantifi ed the overlap between species and identifi ed anuran trophic guilds. Most of the species were generalists in diet (89.5%), some with strong prey dominance and only two species were classifi ed as specialists. Two anurans guilds were identifi ed according to diet structure and habitat use: “ground foraging anurans, consuming Formicidae and Isoptera” and “arboreal ‘sit-and-wait’ predators, primarily consuming arachnids”. A considerable number of species did not clearly group in community trophic structure analysis. The level of taxonomic resolution with that preys are worked affects analysis of trophic niches segregation when analyzing regional and local patterns. Anuran species of tropical dry forest in the Colombian Caribbean display trophic resources partitioning at the level of species and/or morphospecies, as a mechanism of coexistence

Trophic Relationships among Five Species of Anura in the Colombian Caribbean Tropical Dry Forest: A Spatial and Temporal Approach

Species of Bufonidae and Leptodactylidae are common in the Colombian tropical dry forest. Although some of them are associated with active foraging and consumption of termites and ants, their trophic ecology is mostly unknown. The diet of five anuran species of Bufonidae (Rhinella horribilis, R. humboldti) and the leptodactylid subfamily Leiuperinae (Engystomops pustulosus, Pleurodema brachyops, and Pseudopaludicola pusilla) was examined at six sites of the Colombian Caribbean in fragments of dry forest and different land uses. A total of 310 food items were identified. The greatest contribution was represented by Coleoptera, Hymenoptera (Formicidae), Isoptera, and Diptera. The species differed in number and volume of prey. Except for Pseudopaludicola pusilla, which behaves as a generalist predator, species had high intake of termites and ants. Engystomops pustulosus preferred termites, Pleurodema brachyops had high consumption of ants and termites, and the two bufonid species were myrmecophagous. Except for Pseudopaludicola pusilla, predator and prey size was related. Most species have overlapping diets (spatially and temporally) when analyzing food items identified at the order level. However, the richness of different prey within these orders allows the coexistence of species. The diet of these species presents similar trends in different habitats throughout their distribution area

Nematodes of Amphibians from the South American Chaco: Distribution, Host Specificity and Ecological Aspects

This is the first review of the nematode parasites of amphibians from Dry Chaco (DC) and Humid Chaco (HC) ecoregions of South America, covering aspects related to their systematics, distribution, host range and ecology, including their life cycles. Of approximately 100 species of amphibians that inhabit these ecoregions, the nematode parasites of 32 species are known. The parasite species consisted of 51 taxa: 27 in HC and 18 in DC. The family Cosmocercidae alone included 18 species. Aplectana hylambatis and Cosmocerca podicipinus showed the widest geographical and host distribution. Leptodactylus bufonius and Rhinella major presented a high number of nematode parasites. The species richness of nematodes was related to the host body sizes and to the strategy to obtain prey. The mean species richness was higher in terrestrial amphibians with intermediate characteristics in the generalist–specialist spectrum in terms of diet, and in amphibians with intermediate characteristics between actively foraging and the “sit-and-wait” approach in terms of searching for prey. The patterns of similarity among amphibian species showed groups linking with their habitats. Nematodes usually have direct life cycles with the infectious form entering the host passively or actively. However, many amphibians are also involved in heteroxenous cycles that develop in the aquatic environment.Fil: Gonzalez, Cynthya Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Hamann, Mónika Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Duré Pitteri, Marta Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

Parasite and reproductive features of Scinax nasicus (Anura: Hylidae) from a South American subtropical area

Desde febrero de 2002 a diciembre de 2004, se analizó la fauna de helmintos parásitos y las características reproductivas de Scinax nasicus en un área cercana a la ciudad de Corrientes, Argentina. La fauna de parásitos helmintos estuvo conformada por 15 especies de helmintos (larvas y adultos) incluyendo trematodes (73%), nematodes (20%) y acantocéfalos (7%). La especie Opisthogonimus sp. presentó la mayor prevalencia (41%) de infección. Los hospedadores definitivos de esta metacercaria son probablemente las serpientes. Scinax nasicus, interviene como segundo hospedador intermediario, infectándose por la penetración directa de cercarias. El número de óvulos maduros por hembra (complemento ovárico) osciló entre 413-3922, mientras que el diámetro medio de los óvulos fue de 0,76 ±0,17mm. Esta especie posee un patrón reproductivo prolongado.From February 2002 to December 2004, the helminth parasite fauna and reproductive features of the frog Scinax nasicus were studied from Corrientes city, Province of Corrientes, Argentina. The parasite richness was 15 species of helminths (larval and adult) including trematodes (73%), nematodes (20%) and acanthocephalans (7%). Opisthogonimus sp. showed the highest prevalence (41%). The definitive hosts of these larval trematodes are probably snakes; S. nasicus acts as second intermediate host, and become infected by direct penetration of cercariae. The number of mature ova per female ranged from 413 to 3922, and the mean mature ovum diameter was 0.76 ±0.17mm. This species has a prolonged reproductive pattern.Fil: Hamann, Mónika Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Kehr, Arturo Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Gonzalez, Cynthya Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Duré Pitteri, Marta Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Schaefer, Eduardo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

Pithecopus hypochondrialis (Orange-legged Leaf Frog): Diet

Pithecopus hypochondrialis is an arboreal frog found in the foothills of the eastern Andean cordillera and savannas of the Orinoquia región in Colombia, through western and eastern Venezuela and parts of the Guianas, and in Brazilian Amazonia between 169–1125 m elev...Fil: Pachón Forero, Sara. Universidad de la Salle;Fil: Blanco Torres, Argelina. Universidad de la Costa.; ColombiaFil: Duré Pitteri, Marta Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

Pithecopus hypochondrialis (Orange-legged Leaf Frog): Diet

Pithecopus hypochondrialis is an arboreal frog found in the foothills of the eastern Andean cordillera and savannas of the Orinoquia región in Colombia, through western and eastern Venezuela and parts of the Guianas, and in Brazilian Amazonia between 169–1125 m elev...Fil: Pachón Forero, Sara. Universidad de la Salle;Fil: Blanco Torres, Argelina. Universidad de la Costa.; ColombiaFil: Duré Pitteri, Marta Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

Phyllomedusa Venusta (Lovely Leaf Frog)

PHYLLOMEDUSA VENUSTA (Lovely Leaf Frog). DIET.Phyllomedusa venusta is an arboreal frog found in northern Colombia, the valley of Magdalena, the Darién on both sides of the ColombiaPanamá border, and western Venezuela. The species is common, but populations are decreasing due to deforestation by agricultural and livestock activities, illegal plantations, human establishments, and use of agrochemicals (Rodríguez-Mahecha et al. 2008. Guía Ilustrada de Fauna del Santuario de Vida Silvestre Los Besotes,Valledupar, Cesar, Colombia. Editorial Panamericana, Formas e Impresos, Bogotá, Colombia. 574 pp.). The food habits and many other aspects of its biology and ecology are unknown. Herein we describe the diet of P. venusta in the dry tropical forest of Colombia at three sites: 1) The Natural Reserve of Civil Society Campoalegre, Municipality Los Cordobas, Department of Cordoba (8.48502°N, 76.19520°W, WGS84; elev. 120 m); 2) Finca Los Mameyales, Municipality Piojó, Department of Atlántico (10.74480°N, 75.09279°W, WGS84; elev. 206 m); 3) Las Delicias farm, Municipality Aracataca, Department of Magdalena (10.58694°N, 74.14224°W, WGS84; elev. 197 m). We examined 28 stomachs of P. venusta collected during 0800–1200 h and 1600–1800 h within forests and disturbed areas. Samples were obtained during 2007 in the dry season (January–March), first rains (April–June), and heavy rains (September–December). SUL (mm), and maximum mouth width (mm) were recorded for each individual. We identified prey to lowest taxonomic level possible (family and genus), and their length and width were measured (complete prey only) using a digital caliper (nearest 0.1 mm). The individual volume of each prey item and the number of prey items per stomach for each prey category were recorded. Volume of each prey item was estimated using the formula of a prolate spheroid. Of the captured frogs, six were females and 22 were males (mean SUL = 67.60 ± 8.76 mm; mean mouth width = 21.76 ± 2.10 mm). The diet consisted of 16 types of prey and was dominated in volume and frequency by orthopterans. Acarina showed the highest numerical contribution (Table 1). It has been suggested that acariphagia occurs in small anurans in terrestrial habits. However, P. venusta is large and arboreal, suggesting that acariphagia is a trophic phenomenon not limited to the species defined by Simon and Toft (1991. Oikos 61:263–278). The large numbers of orthopterans and blattarians consumed are congruent with that reported for other Phyllomedusa spp. (Parmelee 1999. Sci. Pap. Nat. His. Mus. Univ. Kansas 11:1–59; Vaz-Silva et al. 2004. Herpetol. Rev. 35:160; Freitas et al. 2008. Biota Neotrop. 8:101–110). Considering the type and prey proportion, P. venusta appears to be a generalist predator with a sit-and-wait foraging strategy.Fil: Blanco Torres, Argelina. Universidad Nacional de Colombia; ColombiaFil: Duré Pitteri, Marta Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Bonilla, M. A.. Universidad Nacional de Colombia; Colombi