26 research outputs found

    A glimpse at Ethology in Latin America

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    The state of the art of Ethology in five Latin America countries is briefly presented here. The overall outlook regarding research laboratories and themes is promising: the community is numerous, active and there are topics addressing all aspects of animal behavior, especially in large countries like Brazil and Argentina. Ethology as an undergraduate discipline is generally a subcategory of Biology, being taught mainly at Zoology/ Psychology/ Ecology/ Agriculture Courses and at Medical Veterinary Schools, often as an eligible discipline. Ethology as a formal major Graduate Program is rare and mainly restricted to Brazil.Facultad de Ciencias Naturales y Muse

    A glimpse at Ethology in Latin America

    Get PDF
    The state of the art of Ethology in five Latin America countries is briefly presented here. The overall outlook regarding research laboratories and themes is promising: the community is numerous, active and there are topics addressing all aspects of animal behavior, especially in large countries like Brazil and Argentina. Ethology as an undergraduate discipline is generally a subcategory of Biology, being taught mainly at Zoology/ Psychology/ Ecology/ Agriculture Courses and at Medical Veterinary Schools, often as an eligible discipline. Ethology as a formal major Graduate Program is rare and mainly restricted to Brazil.Facultad de Ciencias Naturales y Muse

    Symmetry breaking in mass-recruiting ants: extent of foraging biases depends on resource quality

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    The communication involved in the foraging behaviour of social insects is integral to their success. Many ant species use trail pheromones to make decisions about where to forage. The strong positive feedback caused by the trail pheromone is thought to create a decision between two or more options. When the two options are of identical quality, this is known as symmetry breaking, and is important because it helps colonies to monopolise food sources in a competitive environment. Symmetry breaking is thought to increase with the quantity of pheromone deposited by ants, but empirical studies exploring the factors affecting symmetry breaking are limited. Here, we tested if (i) greater disparity between two food sources increased the degree to which a higher quality food source is favoured and (ii) if the quality of identical food sources would affect the degree of symmetry breaking that occurs. Using the mass-recruiting Pharaoh ant, Monomorium pharaonis, we carried out binary choice tests to investigate how food quality affects the choice and distribution of colony foraging decisions. We found that colonies could coordinate foraging to exploit food sources of greater quality, and a greater contrast in quality between the food sources created a stronger collective decision. Contrary to prediction, we found that symmetry breaking decreased as the quality of two identical food sources increased. We discuss how stochastic effects might lead to relatively strong differences in the amount of pheromone on alternative routes when food source quality is low. Significance statement: Pheromones used by social insects should guide a colony via positive feedback to distribute colony members at resources in the most adaptive way given the current environment. This study shows that when food resources are of equal quality, Pharaoh ant foragers distribute themselves more evenly if the two food sources are both of high quality compared to if both are of low quality. The results highlight the way in which individual ants can modulate their response to pheromone trails which may lead colonies to exploiting resources more evenly when in a resource rich environment

    Multiple factors associated with nest-site selection in a wetland-specialist, the Wren-like Rushbird (Phleocryptes melanops)

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    Diverse factors may limit nest-site selection; however, nest predation has long been considered a main factor driving nest-site selection in birds. Marsh-nesting birds face a particularly important trade-off between habitat features that impede their vision of the approach of potential predators and nest concealment from predators. Here, we analyse how different ecological variables influence nest-site selection in the habitat-specialist Wren-like Rushbird (Phleocryptes melanops) breeding in three different wetlands of the Pampas region of Argentina over 3 years. Rushbirds selected nest sites with higher heights and denser vegetation, compared to random sites. Nest height was positively associated with vegetation height and lower visibility from the point of view of aerial predators, and the nest entrance was oriented towards the region with greatest visibility of the nest from the point of view of Rushbirds. Rushbirds seem to flexibly adjust their nest location in response to high predation risk, building their nests under structures built by other birds when breeding colonies of herons and gulls (potential nest predators) are present. Initial nest-site selection is performed by males, which then attempt to attract females to a rudimentary nest. Females sometimes reject such sites and the male then selects a new nesting location. Our study highlights the potential for flexible sex differences in nest-site selection.Fil: Chiaradia, Nicolas Mariano. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Isacch, Juan Pablo. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Pretelli, Matías Guillermo. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Cardoni, Daniel Augusto. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

    A comparison of the short-term toxicity of cadmium to indigenous and alien gammarid species

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    Amphipods play an important role in many aquatic ecosystems and are commonly used in ecotoxicology and ecosystem health assessment. Several alien gammarids have been introduced in many regions of the world during the last decades. In this study, we investigated if differences in cadmium sensitivity occurred between (1) different species belonging to the family Gammaridae and (2) different populations of the same species originating from a polluted or a non-polluted site. The acute cadmium toxicity to two indigenous (Gammarus pulex and Gammarus fossarum) and four alien (Dikerogammarus villosus, Echinogammarus berilloni, Gammarus roeseli and Gammarus tigrinus) gammarids occurring in Belgium was tested. Significant differences (P < 0.05) in median lethal concentrations (LC50) were found between the different species, with 72 h-LC50s ranging from 6.3 to 268 μg/l and 96 h-LC50s from 4.7 to 88.9 μg/l. No clear trend in Cd sensitivity was found when comparing indigenous and alien gammarids. D. villosus, an alien invasive species, was the most sensitive to Cd toxicity and E. berilloni, another alien species, the least sensitive. In addition, larger Gammarid species were more sensitive to Cd toxicity than smaller ones. No significant differences were found between populations of the same species originating from metal polluted sites or non-polluted sites. Overall, our results showed that considerable differences in Cd sensitivity exist between gammarid species, which should be taken into consideration in environmental risk assessment and water quality standard setting. Finally, our data suggest that alien gammarids would not have an advantage over indigenous gammarids in Cd contaminated environments
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