RESUMO

Pandanus amaryllifolius Roxb. is a special tropical spice crop resource with broad development prospects. It is widely cultivated under a Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg. canopy to improve the comprehensive benefits to Hevea brasiliensis plantations in Hainan Provence, China. However, the effects of intercropping with Hevea brasiliensis on the component number and relative contents of volatile substances in different categories in the Pandanus amaryllifolius leaves are still unknown. Therefore, a Hevea brasiliensis and Pandanus amaryllifolius intercropping experiment was set up to clarify the differences between several cultivated patterns on volatile substances in the Pandanus amaryllifolius leaves, and the key regulatory factors of volatile substances. The results showed that the soil pH was significantly decreased, while soil bulk density, alkali-hydrolyzable nitrogen and available phosphorus contents were significantly increased under the intercropping pattern. The component numbers of esters in volatile substances were increased by 6.20%, while the component numbers of ketones were decreased by 4.26% under the intercropping pattern. Compared with the Pandanus amaryllifolius monoculture, the relative contents of pyrroles, esters and furanones were significantly increased by 8.83%, 2.30% and 8.27%, respectively, while the relative contents of ketones, furans and hydrocarbons were decreased by 1.01%, 10.55% and 9.16% under the intercropping pattern, respectively. The relative contents of pyrroles, esters, furanones, ketones, furans and hydrocarbons were associated with changes in soil pH, soil available phosphorus content and air temperature. The results indicated that the reduction in soil pH and enhancement in soil-available phosphorus may be the main reasons for promoting the relative content of pyrroles and reducing the relative content of hydrocarbons under an intercropping pattern. Overall, Hevea brasiliensis intercropping with Pandanus amaryllifolius could not only improve soil properties, but also significantly increase the relative contents of the main volatile substances in Pandanus amaryllifolius leaves, which could provide a theoretical basis for the application and promotion of high-quality production patterns of Pandanus amaryllifolius.

RESUMO

The goal of this study was to measure food insecurity among families with children in a low-income district of Lima, Peru and to identify the formal and informal food resources available to them that may affect their food security status. In June-July 2019, we collected data from 329 randomly selected households in Villa El Salvador (Lima, Peru). Following a mixed methods approach, we found that the percentage of households using food assistance programs (FAPs) increased with increasing levels of food insecurity, but two FAPs were heavily used by households regardless of food (in)security. The main reasons for using FAPs included financial need, already being signed up in the program, and believing that the food was of nutritional value; the main reasons for non-use were finding the program unnecessary, dislike or poor perceived quality of the food, and not being able to sign up for the program. Similarly, informal food resources, such as buying food on credit or receiving food from someone outside the household, were incrementally used with increased levels of food insecurity. Our study clarifies the relationship between level of household food insecurity and FAP use - FAPs more commonly used by food insecure households were used because of financial need, whereas the FAPs most commonly used by food secure households were those with automatic enrollment. At a programmatic level, our research highlights the need for making nutritious and preferred foods available in FAPs and standardizing the application of enrollment criteria.

Assuntos

RESUMO

Analysis of feeding habits was performed for early life stages of Brachyplatystoma rousseauxii and Brachyplatystoma filamentosum in the Madeira River, Brazil. Stomach contents of B. rousseauxii and B. filamentosum were identified and analysed to provide the percentage of frequency of occurrence (%FO) and area (%A) and the alimentary index (IAi). The order Diptera represented the most important item consumed by both species. This is the first analyses of the trophic ecology of these ecologically and economically important species of the Amazonian region in early life stages.

Assuntos

RESUMO

Terrestriality in Platyrrhine primates is primarily associated with low arboreal resource availability, low predation risk when on the ground and increased contact time with human observers. To test the relationship between these variables and ground use frequency, we studied a group of endangered Coimbra-Filho's titi monkeys (Callicebus coimbrai) in a 14-ha forest fragment in north-eastern Brazil. Terrestriality data were collected on a monthly basis (33 months) using scan sampling procedures from July 2008 to July 2012. Overall, Coimbra-Filho's titi monkeys were recorded during 0.6% of observation time (113 out of 18,164 scans) on the ground. Most of the time on the ground was spent feeding on young leaves (71 records) and the least amount of time on fruits (14 records). Availability of arboreal foods, rainfall, and time of contact with human observers did not influence overall terrestrial behaviour (ground use). However, the timing and nature of the monkeys' terrestrial feeding was strongly related to the absence of arboreal fruit (ß-estimate = -3.078) and young leaf (ß-estimate = -3.515) food resources. We suggest that terrestrial feeding by Coimbra-Filho's titi monkeys could be an adaptation to low arboreal fruit availability and the exploitation of alternative food resources.

Assuntos

RESUMO

Understanding the ecological and social factors that influence group size is a major focus of primate behavioural ecology. Studies of species with fission-fusion social organizations have offered an insightful tool for understanding ecological drivers of group size as associations change over short temporal and spatial scales. Here we investigated how the fission-fusion dynamics of spider monkeys (Ateles geoffroyi) at Runaway Creek, Belize were affected by fruit availability. When males and females were analyzed together, we found no association between fruit availability and subgroup size. However, when females were analyzed separately, we found that when fruit availability increased, so did subgroup size. In all analyses, higher fruit availability did not influence subgroup spatial cohesion. Our results point to the complexity of understanding grouping patterns, in that while ecological factors make groups of specific sizes advantageous, social factors also play an important determining role.

Assuntos

RESUMO

RESUMEN Los Sistemas de Agro Acuicultura Integrada (SAAI) han sido estudiados como opción para la producción de pescado en comunidades con recursos limitados. Así mismo, el uso de perifiton se ha convertido recientemente en una alternativa viable por el aporte de alimento natural de bajo costo. El objetivo de este estudio fue evaluar el efecto del perifiton sobre el desempeño productivo del policultivo Piaractus sp. (cachama híbrida) y Prochilodus magdalenae (bocachico) en SAAI en la comunidad Indígena de Jimaín, Colombia. Se sembraron 1,5 alevinos de cachama híbrida y 1,5 bocachicos/m2, con peso promedio de 0,49 ± 0,14 g y 1,83 ±1,61 g respectivamente, en seis estaques en tierra de 90 m2 tres de los cuales contaron con varas de madera (3 varas/m2) para la fijación de perifiton. La duración del cultivo fue de 135 días. Los tratamientos (CS: con sustrato y SS: sin sustratos) recibieron una dieta suplementaria dos veces al día, calculada como porcentaje de la biomasa con ajuste quincenal. Se realizaron biometrías quincenales. Los datos productivos por especie y para el policultivo se evaluaron mediante ANOVA con un modelo lineal general (p < 0,05). Los datos de peso (g) y longitud estándar (cm) por especie se evaluaron mediante un modelo mixto de medidas repetidas. No se encontraron efectos del sustrato sobre los parámetros productivos analizados tanto para cada especie, como para el policultivo. Se presentó interacción significativa para el peso del bocachico el día 90 (CS: 74,7 y SS: 47,1). Según los resultados obtenidos, la utilización de perifiton y el manejo en policultivo de especies nativas requiere más estudios.

ABSTRACT Integrated agri-aquaculture systems (IAAS) have been studied as an option for fish production in communities with limited resources. Likewise, the use of periphyton has recently become a viable alternative for its contribution of low-cost natural food. The effect of periphyton use on the productive yield of a hybrid cachama and bocachico polyculture in IAAS, was studied in the Jimaín Indigenous community, Colombia. For this experiment, 1.5 hybrid cachama and 1.5 bocachico fingerlings/m2 were stocked with average weights of 0.49 ± 0.14 g and 1.83 ± 1.61 g, respectively, in six 90 m2 land ponds; three of these ponds had wooden dowels (three dowels/m2) for periphyton fixation. The growth evaluation lasted 135 days. The treatments (WS: with substrate and WOS: without substrates) received a supplementary diet, adjusted as a percentage of the biomass with biweekly adjustment, twice a day. Biometrics were performed every two weeks. The productive data by species and for the polyculture were evaluated using an ANOVA with a general linear model (p <0.05). Weight (g) and standard length (cm) data by species were evaluated using a mixed model of repeated measures. No substrate effects were found on the productive parameters analyzed for each species as well as for the polyculture. A significant interaction was observed for bocachico weight on day 90 (WS: 74.7 and WOS: 47.1). According to the obtained results, optimizing the use of periphyton and the management of native species polyculture requires further studies.

Assuntos

RESUMO

Human-dominated environments alter the availability and quality of resources for many species, especially for scavengers that have large home ranges and plastic foraging behaviors that enable them to exploit novel resources. Along the western slope of the Andes, the modification of natural landscapes have resulted in significant declines in native prey, the introduction of non-native species, and an increase in the availability of anthropogenic resources. These factors have likely influenced the resources available to Andean condors (Vultur gryphus), however, data are lacking as to how condor's diet vary along their large latitudinal range. We evaluated differences in Andean condor diet along a ~2500 km latitudinal gradient in Chile from the heavily modified Central zone (32-34°S) to the more pristine Austral zone (44-56°S). We assessed diet composition through the identification of prey remains in condor pellets, and carbon and nitrogen isotope analysis of condor feathers and their primary prey identified from pellet analysis. Our results identified medium- and large-bodied domesticated mammals (ungulates) and introduced exotic species (lagomorphs) as common prey across the study area. Condors from the Central zone had the largest isotopic niche width, probably related to consumption of anthropogenic resources with distinctly high carbon isotope values indicative of C4-based foods likely acquired from landfills or corn-fed livestock. Isotopic niches for condors from the Southern and Austral zones almost completely overlapped. Andean condor diet is strongly influenced by local conditions determining differential access to prey sources. The high dependence of Andean condors on livestock across a large geographical area, and landfills in more (sub)urban areas, may help stabilize their populations via anthropogenic resources subsidies. Long-term dependence on such resources, however, may have health costs including contaminant exposure and greater mortality risk. These data will help identify potential threats related to resource availability and use, and better inform management and conservation decisions.

Assuntos

RESUMO

Knowledge of how animal species use food resources available in the environment can increase our understanding of many ecological processes. However, obtaining this information using traditional methods is difficult for species feeding on a large variety of food items in highly diverse environments. We amplified the DNA of plants for 306 scat and 40 soil samples, and applied an environmental DNA metabarcoding approach to investigate food preferences, degree of diet specialization and diet overlap of seven herbivore rodent species of the genus Ctenomys distributed in southern and midwestern Brazil. The metabarcoding approach revealed that these species consume more than 60% of the plant families recovered in soil samples, indicating generalist feeding habits of ctenomyids. The family Poaceae was the most common food resource retrieved in scats of all species as well in soil samples. Niche overlap analysis indicated high overlap in the plant families and molecular operational taxonomic units consumed, mainly among the southern species. Interspecific differences in diet composition were influenced, among other factors, by the availability of resources in the environment. In addition, our results provide support for the hypothesis that the allopatric distributions of ctenomyids allow them to exploit the same range of resources when available, possibly because of the absence of interspecific competition.

Assuntos

RESUMO

As abelhas da espécie Melipona eburnea forrageiam em busca de recursos como néctar, pólen, resinas, barro e água, além de transportar o lixo para fora da colônia. A atividade de voo das abelhas pode ser influenciada pela oferta de recursos florais, condições internas do ninho, temperatura, umidade relativa, luminosidade, precipitação e velocidade do vento. No entanto, a temperatura influencia diretamente as atividades de forrageamento das abelhas. O presente estudo foi realizado em Rio Branco-Acre, em um meliponário contendo 14 colmeias de M. eburnea, distribuídas em uma área de 600m2, entre dezembro de 2015 e maio de 2016, abrangendo o período chuvoso, com altas temperaturas, e o de seca, em que ocorrem as friagens. As atividades de voo para forrageamento da espécie M. eburnea ocorreram de forma intensa, durante o dia todo, quando as temperaturas estiveram próximas de 20 °C, com variações de, no máximo, 1,9 °C e umidade relativa do ar em torno de 90%. M. eburnea inicia as atividades de forrageio nas primeiras horas da manhã, coletando néctar, água, pólen, resina e barro, com pico de coleta de pólen entre as 05h e 07h; resina e barro entre 09h e 11h e néctar/água entre as 16h e 17h30min. As atividades de voo de M. eburnea são influenciadas quando a temperatura se encontra abaixo de 20 °C ou acima de 30 °C, e a umidade relativa superior a 90%.(AU)

The bees in the Melipona eburnea species forage in search of resources such as nectar, pollen, resins, clay and water, in addition to transporting the garbage out of the colony. The flight activity of the bees can be influenced by the supply of floral resources, internal conditions of the hive, temperature, relative humidity, luminosity, precipitation and wind speed. However, temperature has a direct influence on the foraging activities of bees. This study was carried out in the city of Rio Branco, Acre, in a meliponary containing 14 M. eburnea hives distributed in a 600m2 area between December 2015 and May 2016, including the rainy season with high temperatures and the dry season, when cold chills take place. The foraging activities of the M. eburnea species occurred intensively throughout the day, when temperatures were close to 20 °C, with variations of a maximum of 1.9 °C, and air relative humidity of approximately 90%. M. eburnea initiates the foraging activities in the early hours of the morning, collecting nectar, water, pollen, resin and clay, with a peak of pollen collection between 5 a.m. and 7 a.m.; resin and clay between 9 a.m. and 11 a.m., and nectar/water between 4 p.m. and 5:30 p.m. The flight activities of M. eburnea are influenced when temperature is below 20 °C or above 30 °C, and the relative humidity is greater than 90%.(AU)

Las abejas de la especie Melipona eburnea forrajean en busca de recursos como néctar, polen, resinas, barro y agua, además de transportar la basura hacia fuera de la colonia. La actividad de vuelo de las abejas puede verse influenciada por la oferta de recursos florales, condiciones internas del nido, temperatura, humedad relativa, luminosidad, precipitación y velocidad del viento. Sin embargo, la temperatura influye directamente en las actividades de forraje de las abejas. El presente estudio ha sido realizado en Rio Branco-Acre, en un meliponario que contenía 14 colmenas de M. eburnea, distribuidas en un área de 600m2, entre diciembre de 2015 y mayo de 2016, abarcando el período lluvioso con altas temperaturas y el de sequía, en que se producen los enfriamientos. Las actividades de vuelo para forraje de la especie M. eburnea ocurrieron de forma intensa durante todo el día, cuando las temperaturas estuvieron cerca de los 20 °C, con variaciones de, como máximo, 1,9 °C y humedad relativa del aire alrededor del 90%. M. eburnea inicia las actividades de forraje en las primeras horas de la mañana, recogiendo néctar, agua, polen, resina y barro, con pico de recolección de polen entre las 05 h y 07 h; resina y barro entre las 09 h y las 11 h y néctar / agua entre las 16 h y las 17.30 h. Las actividades de vuelo de M. eburnea se influencian cuando la temperatura se encuentra por debajo de 20 °C o superior a 30 °C y la humedad relativa superior al 90%.(AU)

Assuntos

RESUMO

As abelhas da espécie Melipona eburnea forrageiam em busca de recursos como néctar, pólen, resinas, barro e água, além de transportar o lixo para fora da colônia. A atividade de voo das abelhas pode ser influenciada pela oferta de recursos florais, condições internas do ninho, temperatura, umidade relativa, luminosidade, precipitação e velocidade do vento. No entanto, a temperatura influencia diretamente as atividades de forrageamento das abelhas. O presente estudo foi realizado em Rio Branco-Acre, em um meliponário contendo 14 colmeias de M. eburnea, distribuídas em uma área de 600m2, entre dezembro de 2015 e maio de 2016, abrangendo o período chuvoso, com altas temperaturas, e o de seca, em que ocorrem as friagens. As atividades de voo para forrageamento da espécie M. eburnea ocorreram de forma intensa, durante o dia todo, quando as temperaturas estiveram próximas de 20 °C, com variações de, no máximo, 1,9 °C e umidade relativa do ar em torno de 90%. M. eburnea inicia as atividades de forrageio nas primeiras horas da manhã, coletando néctar, água, pólen, resina e barro, com pico de coleta de pólen entre as 05h e 07h; resina e barro entre 09h e 11h e néctar/água entre as 16h e 17h30min. As atividades de voo de M. eburnea são influenciadas quando a temperatura se encontra abaixo de 20 °C ou acima de 30 °C, e a umidade relativa superior a 90%.(AU)

The bees in the Melipona eburnea species forage in search of resources such as nectar, pollen, resins, clay and water, in addition to transporting the garbage out of the colony. The flight activity of the bees can be influenced by the supply of floral resources, internal conditions of the hive, temperature, relative humidity, luminosity, precipitation and wind speed. However, temperature has a direct influence on the foraging activities of bees. This study was carried out in the city of Rio Branco, Acre, in a meliponary containing 14 M. eburnea hives distributed in a 600m2 area between December 2015 and May 2016, including the rainy season with high temperatures and the dry season, when cold chills take place. The foraging activities of the M. eburnea species occurred intensively throughout the day, when temperatures were close to 20 °C, with variations of a maximum of 1.9 °C, and air relative humidity of approximately 90%. M. eburnea initiates the foraging activities in the early hours of the morning, collecting nectar, water, pollen, resin and clay, with a peak of pollen collection between 5 a.m. and 7 a.m.; resin and clay between 9 a.m. and 11 a.m., and nectar/water between 4 p.m. and 5:30 p.m. The flight activities of M. eburnea are influenced when temperature is below 20 °C or above 30 °C, and the relative humidity is greater than 90%.(AU)

Las abejas de la especie Melipona eburnea forrajean en busca de recursos como néctar, polen, resinas, barro y agua, además de transportar la basura hacia fuera de la colonia. La actividad de vuelo de las abejas puede verse influenciada por la oferta de recursos florales, condiciones internas del nido, temperatura, humedad relativa, luminosidad, precipitación y velocidad del viento. Sin embargo, la temperatura influye directamente en las actividades de forraje de las abejas. El presente estudio ha sido realizado en Rio Branco-Acre, en un meliponario que contenía 14 colmenas de M. eburnea, distribuidas en un área de 600m2, entre diciembre de 2015 y mayo de 2016, abarcando el período lluvioso con altas temperaturas y el de sequía, en que se producen los enfriamientos. Las actividades de vuelo para forraje de la especie M. eburnea ocurrieron de forma intensa durante todo el día, cuando las temperaturas estuvieron cerca de los 20 °C, con variaciones de, como máximo, 1,9 °C y humedad relativa del aire alrededor del 90%. M. eburnea inicia las actividades de forraje en las primeras horas de la mañana, recogiendo néctar, agua, polen, resina y barro, con pico de recolección de polen entre las 05 h y 07 h; resina y barro entre las 09 h y las 11 h y néctar / agua entre las 16 h y las 17.30 h. Las actividades de vuelo de M. eburnea se influencian cuando la temperatura se encuentra por debajo de 20 °C o superior a 30 °C y la humedad relativa superior al 90%.(AU)

Assuntos

RESUMO

Food resources in school neighborhoods can negatively influence diet; however, this environment is understudied. This study characterized the school neighborhood food environment in Guadalajara (n=11), Puerto Vallarta (n=7), and Mexico City (n=14). Convenience stores, table-service restaurants, and taco stands were highly available in all three cities. Grocery stores were highly available in Mexico City school neighborhoods, yet less frequently observed in Guadalajara and Puerto Vallarta. Socioeconomic differences in food cart and grocery store availability were observed in Guadalajara and Puerto Vallarta. Policy and intervention strategies are needed to address the saturation of food resources in Mexico school neighborhoods.

Assuntos

RESUMO

During flight, hummingbirds achieve the maximum aerobic metabolism rates within vertebrates. To meet such demands, these birds have to take in as much energy as possible, using strategies such as selecting the best food resources and adopting behaviors that allow the greatest energy gains. We tested whether hummingbirds choose sources that have higher sugar concentrations, and investigated their behaviors near and at food resources. The study was conducted at Atlantic forest remnant in Brazil, between June and December 2012. Four patches were provided with artificial feeders, containing sucrose solutions at concentrations of 5%, 15%, 25% and 35% weight/volume. Hummingbird behaviors were recorded using the ad libitum method with continuous recording of behaviors. The following species were observed: the Brazilian ruby Clytolaema rubricauda (Boddaert, 1783), Violet-capped woodnymph Thalurania glaucopis (Gmelin, 1788), Scale-throated hermit Phaethornis eurynome (Lesson, 1832), White-throated hummingbird Leucochloris albicollis (Vieillot, 1818), Versicoloured emerald Amazilia versicolor (Vieillot, 1818), Glittering-bellied emerald Chlorostilbon lucidus (Shaw, 1812) and other Phaethornis spp. C. rubricauda, P. eurynome and Phaethornis spp. visited the 35%-sucrose feeders more often, while the T. glaucopis visited the 25%-sucrose feeders more often. L. albicollis and A. versicolor visited more often solutions with sugar concentration of 15%. C. lucidus visited all patches equally. Three behavioral strategies were observed: 1) C. rubricauda and T. glaucopis exhibited interspecific and intraspecific dominance; 2) the remaining species exhibited subordinance to the dominant hummingbirds, and 3) P. eurynome and Phaethornis spp. adopted a hide-and-wait strategy to the dominant hummingbird species. The frequency of aggressive behaviors was correlated with the time the hummingbird spent feeding, and bird size. [...](AU)

Assuntos

RESUMO

This study was carried out in a section of the middle course of the Teles Pires River, a clear water river that drains ancient and highly eroded geological formations, and where five hydropower plants are planned or in construction. In this study we tested the hypothesis that local fish fauna is mainly sustained by autochthonous food resources, with modest changes in the trophic structure of fish assemblages along the hydrometric cycle. Sampling was performed every three months between July 2008 and May 2009 at seven sites distributed along a 50-km section of the river. Piscivores was the most representative group in terms of biomass, abundance and species richness, followed by herbivores, insectivores and omnivores. The trophic structure did not change significantly during the hydrometric cycle, only omnivores showed significant temporal variation in abundance. The main food resources consumed by the ichthyofauna were of autochthonous origin, mainly immature aquatic insects and fish. Eight of 34 species showed temporal variations of the food resources consumed. Our results corroborate the hypothesis that the fish fauna of large, clear water rivers can be sustained by autochthonous resources. This contributes to understanding some determinants of fish production in large Neotropical rivers.(AU)

Este estudo foi desenvolvido em um trecho do curso médio do rio Teles Pires, um rio de águas claras que drena regiões de terreno geologicamente antigos, e onde cinco usinas hidrelétricas estão previstas ou em construção. Dado a transparência da água e as características do terreno nos hipotetizamos que a fauna de peixes local é principalmente sustentada por recurso autóctone e com alterações pouco significativas na estrutura trófica ao longo de um ciclo hidrométrico. As amostragens foram realizadas trimestralmente entre julho/2008 e maio/2009 em sete pontos dispostos ao longo de um trecho de cerca de 50 km do rio. Piscívoros foram os mais representativos em biomassa, número de exemplares e riqueza de espécies, seguidos pelos herbívoros, insetívoros e onívoros. Não houve mudança significativa na estrutura trófica da assembleia ao longo do ciclo hidrométrico, apenas onívoros apresentaram significativa variação temporal na abundância. Os principais recursos alimentares utilizados pela ictiofauna foram de origem autóctone, sobretudo insetos imaturos e peixes. Oito de 34 espécies apresentaram variação temporal na dieta. Os resultados corroboram a hipótese de que grandes rios de água clara podem ser sustentados majoritariamente por recursos autóctone. Desta forma, este estudo contribui para a compreensão de alguns fatores determinantes da produção secundária em grandes rios Neotropicais.(AU)

Assuntos

RESUMO

Population-level morphometrc variation of the Mountain Mullet (Agonostomus monticola) was assessed in 419 adult specimens from 25 sample sites (river basins) across its Middle American distribution (Pacific and Atlantic-Caribbean drainages). This analysis was based on 36 standardized linear measurements and 19 landmarks on geometric morphometrics approach. Discriminant function analysis (DFA) revealed 19 linear morphological characters with significant variation among groups. Geometrically, the most notable changes were associated to the curvature of the frontal region of the head, the anterior and posterior insertion of the first dorsal and anal fins. The resulting grouping based on the DFA and geometric morphometrics techniques (Pacific-A, Pacific-B and NE México-Caribbean) were similar to those previously recovered by genetic techniques, where the Pacific-B (Ayuquila river basin) was the most different group. Our results provide morphological evidence for considering Agonostomus monticola as a complex of evolutionary entities, represented by two forms in the Pacific Ocean and another in the Atlantic Ocean.(AU)

La variación morfométrica de poblaciones de la lisa de montaña Agonostomus monticola fue evaluada en 419 especímenes adultos recolectados en 25 sitios (cuencas) a través de su distribución mesoamericana (Pacífico, Atlántico y cuencas del Caribe). El análisis fue basado en 36 medidas lineales estandarizadas y 19 puntos de referencia basados en morfometría geométrica. El análisis de función discriminante (AFD) reveló 19 caracteres morfométricos con variación significativa entre grupos. Geométricamente, los cambios más notables estuvieron asociados con la curvatura de la región frontal de la cabeza y la inserción anterior y posterior de la primera aleta dorsal y de la aleta anal. Los agrupamientos resultantes del AFD y del análisis de morfometría geométrica (Pacífico-A, Pacífico-B y NE México-Caribe) fueron similares con los previamente definidos mediante técnicas genéticas. El grupo Pacífico-B (cuenca de Ayuquila) fue el más disímil. Nuestros resultados proveen evidencia morfológica para considerar a Agonostomus monticola como un complejo de entidades evolutivas, representadas por dos formas en la cuenca del océano Pacífico y una forma en la cuenca del océano Atlántico.(AU)

Assuntos

RESUMO

During flight, hummingbirds achieve the maximum aerobic metabolism rates within vertebrates. To meet such demands, these birds have to take in as much energy as possible, using strategies such as selecting the best food resources and adopting behaviors that allow the greatest energy gains. We tested whether hummingbirds choose sources that have higher sugar concentrations, and investigated their behaviors near and at food resources. The study was conducted at Atlantic forest remnant in Brazil, between June and December 2012. Four patches were provided with artificial feeders, containing sucrose solutions at concentrations of 5%, 15%, 25% and 35% weight/volume. Hummingbird behaviors were recorded using the ad libitum method with continuous recording of behaviors. The following species were observed: the Brazilian ruby Clytolaema rubricauda (Boddaert, 1783), Violet-capped woodnymph Thalurania glaucopis (Gmelin, 1788), Scale-throated hermit Phaethornis eurynome (Lesson, 1832), White-throated hummingbird Leucochloris albicollis (Vieillot, 1818), Versicoloured emerald Amazilia versicolor (Vieillot, 1818), Glittering-bellied emerald Chlorostilbon lucidus (Shaw, 1812) and other Phaethornis spp. C. rubricauda, P. eurynome and Phaethornis spp. visited the 35%-sucrose feeders more often, while the T. glaucopis visited the 25%-sucrose feeders more often. L. albicollis and A. versicolor visited more often solutions with sugar concentration of 15%. C. lucidus visited all patches equally. Three behavioral strategies were observed: 1) C. rubricauda and T. glaucopis exhibited interspecific and intraspecific dominance; 2) the remaining species exhibited subordinance to the dominant hummingbirds, and 3) P. eurynome and Phaethornis spp. adopted a hide-and-wait strategy to the dominant hummingbird species. The frequency of aggressive behaviors was correlated with the time the hummingbird spent feeding, and bird size. [...]

Assuntos

RESUMO

This study was carried out in a section of the middle course of the Teles Pires River, a clear water river that drains ancient and highly eroded geological formations, and where five hydropower plants are planned or in construction. In this study we tested the hypothesis that local fish fauna is mainly sustained by autochthonous food resources, with modest changes in the trophic structure of fish assemblages along the hydrometric cycle. Sampling was performed every three months between July 2008 and May 2009 at seven sites distributed along a 50-km section of the river. Piscivores was the most representative group in terms of biomass, abundance and species richness, followed by herbivores, insectivores and omnivores. The trophic structure did not change significantly during the hydrometric cycle, only omnivores showed significant temporal variation in abundance. The main food resources consumed by the ichthyofauna were of autochthonous origin, mainly immature aquatic insects and fish. Eight of 34 species showed temporal variations of the food resources consumed. Our results corroborate the hypothesis that the fish fauna of large, clear water rivers can be sustained by autochthonous resources. This contributes to understanding some determinants of fish production in large Neotropical rivers.(AU)

Este estudo foi desenvolvido em um trecho do curso médio do rio Teles Pires, um rio de águas claras que drena regiões de terreno geologicamente antigos, e onde cinco usinas hidrelétricas estão previstas ou em construção. Dado a transparência da água e as características do terreno nos hipotetizamos que a fauna de peixes local é principalmente sustentada por recurso autóctone e com alterações pouco significativas na estrutura trófica ao longo de um ciclo hidrométrico. As amostragens foram realizadas trimestralmente entre julho/2008 e maio/2009 em sete pontos dispostos ao longo de um trecho de cerca de 50 km do rio. Piscívoros foram os mais representativos em biomassa, número de exemplares e riqueza de espécies, seguidos pelos herbívoros, insetívoros e onívoros. Não houve mudança significativa na estrutura trófica da assembleia ao longo do ciclo hidrométrico, apenas onívoros apresentaram significativa variação temporal na abundância. Os principais recursos alimentares utilizados pela ictiofauna foram de origem autóctone, sobretudo insetos imaturos e peixes. Oito de 34 espécies apresentaram variação temporal na dieta. Os resultados corroboram a hipótese de que grandes rios de água clara podem ser sustentados majoritariamente por recursos autóctone. Desta forma, este estudo contribui para a compreensão de alguns fatores determinantes da produção secundária em grandes rios Neotropicais.(AU)

Assuntos

RESUMO

Abstract Ecological studies on food webs have considerably increased in recent decades, especially in aquatic communities. Because Chironomidae family are highly specious, occurring in almost all aquatic habitats is considered organisms-key to initiate studies on ecological relationships and trophic webs. We tested the hypothesis that the diversity of the morphospecies diet reflects differences on both the food items available among habitats and the preferences of larval feeding. We analyzed the gut content of the seven most abundant Chironomidae morphospecies of the different habitats from the Upper Paraná River. We categorized the food items found into algae, fungal spores, fragments of plants, algae and animal fragments and sponge spicules. We observed the algae predominance in the gut content of morphospecies from lakes. Considering the different regions from each lake, we registered the highest food abundance in the littoral regions in relation to the central regions. From the variety of feeding habits (number of item kinds), we classified Chironomus strenzkei, Tanytarsus sp.1, Procladius sp.1 as generalist morphospecies. We found a nested pattern between food items and Chironomidae morphospecies, where some items were common to all taxa (e.g., Bacillariophyceae algae, especially), while others were found in specific morphospecies (e.g., animals fragments found in Procladius sp.1). The algae represented the most percentage of gut contents of Chironomidae larvae. This was especially true for the individuals from littoral regions, which is probably due to the major densities of algae associated to macrophytes, which are abundant in these regions. Therefore, the feeding behavior of these morphospecies was generalist and not selective, depending only of the available resources.

Resumo Estudos sobre redes alimentares têm aumentado consideravelmente nas últimas décadas em pesquisas de ecologia, principalmente em comunidades aquáticas. Em função Família Chironomidae ser altamente especiosa, ocorrendo em quase todos os hábitats aquáticos, é considerada como organismos-chave para estudos preliminares sobre as relações ecológicas como redes tróficas. Nós testamos a hipótese de que a diversidade de dietas das morfoespécies reflete diferenças tanto na disponibilidade dos itens alimentares entre os hábitats analisados, quanto preferencias alimentares das larvas. Nós analisamos o conteúdo digestivo das sete morfoespécies mais abundantes de diferentes habitats da planície de inundação do alto rio Paraná. Nós categorizamos os itens alimentares encontrados como algas, esporos de fungos, fragmentos vegetais, fragmentos de algas ou de animais e espículas de esponjas. Nós observamos a predominância de algas no conteúdo digestivo das morfoespécies lacustres. Considerando as diferentes regiões de cada lagoa, nós registramos as maiores abundâncias de alimentos nas regiões litorâneas, quando comparadas com as regiões centrais. A partir da variedade de hábitos alimentares (número de tipos de itens), classificamos Chironomus strenzkei, Tanytarsus sp.1 e Procladius sp.1 como morfoespécies generalistas. Nós encontramos um padrão aninhado entre os itens alimentares e as morfoespécies de Chironomidae, onde alguns itens foram comuns a todos os táxons (por exemplo, algas da Classe Bacillariophyceae), enquanto outros foram encontrados em morfoespécies mais especificas (por exemplo, fragmentos de animais encontrados em Procladius sp.1). As algas representaram a maior porcentagem do conteúdo digestivo das larvas de Chironomidae. Este fato foi especialmente verdadeiro para os indivíduos das regiões litorâneas, o qual é devido, provavelmente, pelas maiores densidades de algas associadas à macrófitas, que são abundantes nessas regiões. Portanto, o comportamento alimentar dessas morfoespécies foi generalista e não seletivo, dependendo apenas dos recursos disponíveis.

Assuntos

RESUMO

Abstract Ecological studies on food webs have considerably increased in recent decades, especially in aquatic communities. Because Chironomidae family are highly specious, occurring in almost all aquatic habitats is considered organisms-key to initiate studies on ecological relationships and trophic webs. We tested the hypothesis that the diversity of the morphospecies diet reflects differences on both the food items available among habitats and the preferences of larval feeding. We analyzed the gut content of the seven most abundant Chironomidae morphospecies of the different habitats from the Upper Paranل River. We categorized the food items found into algae, fungal spores, fragments of plants, algae and animal fragments and sponge spicules. We observed the algae predominance in the gut content of morphospecies from lakes. Considering the different regions from each lake, we registered the highest food abundance in the littoral regions in relation to the central regions. From the variety of feeding habits (number of item kinds), we classified Chironomus strenzkei, Tanytarsus sp.1, Procladius sp.1 as generalist morphospecies. We found a nested pattern between food items and Chironomidae morphospecies, where some items were common to all taxa (e.g., Bacillariophyceae algae, especially), while others were found in specific morphospecies (e.g., animals fragments found in Procladius sp.1). The algae represented the most percentage of gut contents of Chironomidae larvae. This was especially true for the individuals from littoral regions, which is probably due to the major densities of algae associated to macrophytes, which are abundant in these regions. Therefore, the feeding behavior of these morphospecies was generalist and not selective, depending only of the available resources.(AU)

Resumo Estudos sobre redes alimentares têm aumentado consideravelmente nas ْltimas décadas em pesquisas de ecologia, principalmente em comunidades aquلticas. Em funçمo Famيlia Chironomidae ser altamente especiosa, ocorrendo em quase todos os hلbitats aquلticos, é considerada como organismos-chave para estudos preliminares sobre as relaçُes ecolَgicas como redes trَficas. Nَs testamos a hipَtese de que a diversidade de dietas das morfoespécies reflete diferenças tanto na disponibilidade dos itens alimentares entre os hلbitats analisados, quanto preferencias alimentares das larvas. Nَs analisamos o conteْdo digestivo das sete morfoespécies mais abundantes de diferentes habitats da planيcie de inundaçمo do alto rio Paranل. Nَs categorizamos os itens alimentares encontrados como algas, esporos de fungos, fragmentos vegetais, fragmentos de algas ou de animais e espيculas de esponjas. Nَs observamos a predominância de algas no conteْdo digestivo das morfoespécies lacustres. Considerando as diferentes regiُes de cada lagoa, nَs registramos as maiores abundâncias de alimentos nas regiُes litorâneas, quando comparadas com as regiُes centrais. A partir da variedade de hلbitos alimentares (nْmero de tipos de itens), classificamos Chironomus strenzkei, Tanytarsus sp.1 e Procladius sp.1 como morfoespécies generalistas. Nَs encontramos um padrمo aninhado entre os itens alimentares e as morfoespécies de Chironomidae, onde alguns itens foram comuns a todos os tلxons (por exemplo, algas da Classe Bacillariophyceae), enquanto outros foram encontrados em morfoespécies mais especificas (por exemplo, fragmentos de animais encontrados em Procladius sp.1). As algas representaram a maior porcentagem do conteْdo digestivo das larvas de Chironomidae. Este fato foi especialmente verdadeiro para os indivيduos das regiُes litorâneas, o qual é devido, provavelmente, pelas maiores densidades de algas associadas à macrَfitas, que sمo abundantes nessas regiُes. Portanto, o comportamento alimentar dessas morfoespécies foi generalista e nمo seletivo, dependendo apenas dos recursos disponيveis.(AU)

Assuntos

RESUMO

Abstract Ecological studies on food webs have considerably increased in recent decades, especially in aquatic communities. Because Chironomidae family are highly specious, occurring in almost all aquatic habitats is considered organisms-key to initiate studies on ecological relationships and trophic webs. We tested the hypothesis that the diversity of the morphospecies diet reflects differences on both the food items available among habitats and the preferences of larval feeding. We analyzed the gut content of the seven most abundant Chironomidae morphospecies of the different habitats from the Upper Paraná River. We categorized the food items found into algae, fungal spores, fragments of plants, algae and animal fragments and sponge spicules. We observed the algae predominance in the gut content of morphospecies from lakes. Considering the different regions from each lake, we registered the highest food abundance in the littoral regions in relation to the central regions. From the variety of feeding habits (number of item kinds), we classified Chironomus strenzkei, Tanytarsus sp.1, Procladius sp.1 as generalist morphospecies. We found a nested pattern between food items and Chironomidae morphospecies, where some items were common to all taxa (e.g., Bacillariophyceae algae, especially), while others were found in specific morphospecies (e.g., animals fragments found in Procladius sp.1). The algae represented the most percentage of gut contents of Chironomidae larvae. This was especially true for the individuals from littoral regions, which is probably due to the major densities of algae associated to macrophytes, which are abundant in these regions. Therefore, the feeding behavior of these morphospecies was generalist and not selective, depending only of the available resources.

Resumo Estudos sobre redes alimentares têm aumentado consideravelmente nas últimas décadas em pesquisas de ecologia, principalmente em comunidades aquáticas. Em função Família Chironomidae ser altamente especiosa, ocorrendo em quase todos os hábitats aquáticos, é considerada como organismos-chave para estudos preliminares sobre as relações ecológicas como redes tróficas. Nós testamos a hipótese de que a diversidade de dietas das morfoespécies reflete diferenças tanto na disponibilidade dos itens alimentares entre os hábitats analisados, quanto preferencias alimentares das larvas. Nós analisamos o conteúdo digestivo das sete morfoespécies mais abundantes de diferentes habitats da planície de inundação do alto rio Paraná. Nós categorizamos os itens alimentares encontrados como algas, esporos de fungos, fragmentos vegetais, fragmentos de algas ou de animais e espículas de esponjas. Nós observamos a predominância de algas no conteúdo digestivo das morfoespécies lacustres. Considerando as diferentes regiões de cada lagoa, nós registramos as maiores abundâncias de alimentos nas regiões litorâneas, quando comparadas com as regiões centrais. A partir da variedade de hábitos alimentares (número de tipos de itens), classificamos Chironomus strenzkei, Tanytarsus sp.1 e Procladius sp.1 como morfoespécies generalistas. Nós encontramos um padrão aninhado entre os itens alimentares e as morfoespécies de Chironomidae, onde alguns itens foram comuns a todos os táxons (por exemplo, algas da Classe Bacillariophyceae), enquanto outros foram encontrados em morfoespécies mais especificas (por exemplo, fragmentos de animais encontrados em Procladius sp.1). As algas representaram a maior porcentagem do conteúdo digestivo das larvas de Chironomidae. Este fato foi especialmente verdadeiro para os indivíduos das regiões litorâneas, o qual é devido, provavelmente, pelas maiores densidades de algas associadas à macrófitas, que são abundantes nessas regiões. Portanto, o comportamento alimentar dessas morfoespécies foi generalista e não seletivo, dependendo apenas dos recursos disponíveis.

RESUMO

Abstract We analyzed the phenology of Ficus adhatodifolia Schott ex Spreng. (23 fig tree) and F. eximia Schott (12 fig tree) for 74 months in a remnant of seasonal semi-deciduous forest (23°27’S and 51°15’W), Southern Brazil and discussed their importance to frugivorous. Leaf drop, leaf flush, syconia production and dispersal were recorded. These phenophases occurred year-round, but seasonal peaks were recorded in both leaf phenophases for F. eximia and leaf flushing for F. adhatodifolia. Climatic variables analyzed were positively correlated with reproductive phenophases of F. adhatodifolia and negatively correlated with the vegetative phenophases of F. eximia. In despite of environmental seasonality, little seasonality in the phenology of two species was observed, especially in the reproductive phenology. Both species were important to frugivorous, but F. adhatodifolia can play a relevant role in the remnant.

Resumo Foi analisada a fenologia de Ficus adhatodifolia Schott ex Spreng. (23 indivíduos) e F. eximia Schott (12 indivíduos), por 74 meses em um remanescente de floresta estacional semidecidual (23°27’S e 51°15’W, centro de visitantes) no sul do Brasil e discutido sua importância para os frugívoros. Foram registradas as fenofases: queda e brotamento de folhas, produção e dispersão de siconios. Estas fenofases ocorreram ao longo do ano, porém picos sazonais foram registrados em abscisão e brotamento foliares para F. eximia e brotamento foliar para F. adhatodifolia. As variáveis climáticas analisadas foram positivamente correlacionadas com as fenofases reprodutivas de F. adhatodifolia e negativamente correlacionadas com as fenofases vegetativas de F. eximia. Apesar da sazonalidade ambiental, foi observada baixa variação sazonal na fenologia das duas espécies, especialmente na fenologia reprodutiva. Ambas as espécies foram consideradas importantes para os frugivoros, porém F. adhatodifolia pode desempenhar papel de destaque no fragmento florestal.

Assuntos