Tengo una cita: respuesta a Martín Oesterheld

Paradójicamente, el artículo en donde critico al número de citas de un manuscrito como estimador de su calidad fue tempranamente citado. Me agrada esta cita: el interlocutor posee experiencia en el tema y la charla promete ser interesante. Adicionalmente, dispara un debate útil para mejorar el actual sistema indirecto de evaluación académica. Aprovecharé esta cita para primero rescatar las coincidencias, y segundo discutir las disidencias. Luego veremos quién paga la cuenta.Fil: Farji Brener, Alejandro Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentin

Trash to treasure: Leaf-cutting ants repair nest-mound damage by recycling refuse dump materials

Animals adjust their behaviors in response to changing environmental conditions because the costs and benefits of such behaviors change as conditions change. The reuse of materials from waste (i.e., recycling) rarely occurs in social insects because it may imply significant health risks and behavioral difficulties. However, the benefit of reusing may exceed its costs under certain circumstances. For the first time, we document that ants "recycle" refuse materials to repair nest-mound damage. We conducted a series of field measurements and experiments to test the hypotheses that fluctuations in this behavior in the leaf-cutting ant Acromyrmex lobicornis depend on 1) seasonal changes in the tendency to reject refuse (a proxy of changes in their pathogen levels), and/or 2) seasonal foraging restrictions. We 1) measured the rejection of foraging ants toward experimental refuse piles among seasons and 2) analyzed how mound condition, temperatures of fungus chamber and soil surface, and foraging activity explained this behavior using a classification tree, a powerful recursive partitioning method. Foraging ants showed similar rejection levels toward refuse piles in different seasons. Colonies repaired mound damage with refuse materials only during the hottest season and when they had low foraging rates, suggesting that ants recycle their refuse by a hierarchical set of decisions dependent on the risk of fungal damage and foraging restrictions. Repairing the mounds is essential during summer, when temperatures inside damaged mounds are lethal to their fungus cultures. However, these high temperatures also restrict the foraging activity, reducing the collection of building materials. Thus, colonies with lower foraging rates apparently use their refuse to repair mounds because this substrate requires less searching and carrying time. The use of refuse did not affect the colony growth rate. This illustrates how ants integrate information about food, hygienic and nest conditions through a novel and plastic behavior: recycling of their discarded materials.Fil: Farji Brener, Alejandro Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Tadey, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin

Successful invasions of hymenopteran insects into NW Patagonia

We describe the successful invasion of hymenopteran insects into NW Patagonia. We analyse the importance of the invading species and the characteristics of the invaded community, as well as the role of disturbance on the invasion process, by presenting the most conspicuous of the best documented case studies: the wasps Vespula germanica and Sirex noctilio, the bumblebee Bombus ruderatus, and the leaf cutting ant Acromyrmex lobicornis. In their native habitats, these insects are common and have a wide geographical range. In turn, ecological plasticity appears to be the most important demographic trait related to invasion success shared by these species. We believe that climatic matching between the community invaded and the invader’s native range together with the absence of natural enemies are the community characteristics better related to invasion success. The role played by biotic resistance remains unclear. The successful establishment of the studied cases is related to some extent to resource liberation due to exogenous disturbance, or competitive displacement of a native species. This might suggest that the native hymenoptera community of NW Patagonia is species saturated, which in turn, could imply that species interactions are important in the community structure in environments where physical variables have been regarded as key factors

Ecologists or egologists? When the ideas enslave the data

Algunos ecólogos se apasionan tanto por sus ideas que terminan manipulando la información para que los resultados se ajusten a sus predicciones. En este trabajo describo ciertas características de estos investigadores (denominados ególogos porque viven el fracaso de sus hipótesis como una derrota de su ego) y detallo las formas mediante las cuales logran someter a los datos por las ideas. La manipulación de datos raros y la inquisición estadística (torturar los datos hasta que confiesen lo que se desea escuchar) son algunos de los procedimientos más comunes. Para comprender mejor el funcionamiento de la naturaleza, los ecólogos deberíamos ser esclavos de los datos y no de las hipótesis que guiaron su recolección.Some ecologists feel in love with its ideas and, as a result, they tend to manipulate the information to artificially improve the fit between results and predictions. In this work I describe certain characteristics of this researchers (denominated egologist because they suffer the rejection of its ideas as a defeat of its ego), and detail how they enslave the data by their ideas. The manipulation of outliers' data and statistical inquisition (to torture the data until they confess) are some of the more frequent procedures. To better understand how nature works we, as ecologists, should be enslaved by the data and not by the hypotheses that guided their collection

Como lidiar con las desventajas de vivir en sociedades densas: Reglas de tránsito en hormigas cortadoras de hojas

Transporting food from production centers to consumption centers is a challenge for densely populated societies. To avoid delays, the trail system must be efficient and the behavior of the transporters must reduce the probability of collisions. This work, describes how Leaf-Cutting Ants (LCA) solve these dilemmas by optimizing their trail design and performing behaviors that avoid bottlenecks and delays. On the one hand, the LCA build trails wide enough to avoid traffic jams at times of peak foraging activity. Also, at the bifurcation points, the sum of the branching trail widths is always higher than the width of the precedent trunk trail. Finally, LCA builds their branching trails with angles that reduce the maintenance cost of the new trail sector or of the total trail length, depending on which factor is more limiting. On the other hand, LCA shows a range of behaviors that avoid delays: minima workers can travel on the leaf fragments thereby reducing flux density, unloaded workers remove obstacles from the trail, ants carry extra-large loads mainly during situations of low traffic, ants maintain their lane when turning, and foragers show priority rules during jam situations. These examples illustrate how ants, using simple behavioral rules that arise from positive interactions among individuals, can solve complex problems such as traffic regulation.Transportar alimentos desde los centros de producción hacia los centros de consumo es un desafío para las sociedades densamente pobladas. Para evitar retrasos, el sistema de senderos debe ser eficiente y el comportamiento de los transportistas debe reducir la probabilidad de colisiones. En este trabajo se describe cómo las hormigas cortadoras de hojas (HCH) lidian con ese dilema, a través de la construcción de senderos de forrajeo que minimizan los embotellamientos y mediante comportamientos que reducen los retrasos. Por un lado, las HCH construyen senderos que son suficientemente anchos como para evitar aglomeraciones en los momentos de máxima actividad. En adición, en lo puntos de bifurcación la suma del ancho de las ramificaciones siempre es mayor que el sendero troncal precedente, lo cual agiliza el tránsito. Finalmente, las HCH construyen bifurcaciones del sendero troncal con ángulos que reducen el costo de mantenimiento del nuevo tramo o del recorrido total, dependiendo de cuál factor sea más limitante. Por otra parte, las hormigas muestran un abanico de comportamientos que evitan los retrasos: pueden viajar sobre los fragmentos de hojas y reducir así la densidad de flujo, remueven obstáculos para minimizar aglomeraciones, acarrean cargas pesadas en los momentos de menor tránsito, mantienen el carril al doblar, y establecen prioridades en situaciones de “embotellamientos”. Estos ejemplos ilustran cómo las hormigas, emplean reglas simples de comportamiento que surgen de interacciones positivas entre los individuos, para resolver problemas complejos como la regulación del tránsito.Fil: Farji Brener, Alejandro Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Instituto D/invest.en Biodiversidad y Medioambiente; Argentin

Association of flower color with pollen reward may explain increased bumblebee visitation to the Scotch broom yellow morph

Given that pollinators usually visit flowers for hidden rewards, they need to rely on floral traits that indicate reward status (“honest signals”). However, the relationship between pollination, honest signals, and floral rewards is little documented in natural conditions. The Scotch broom (Cytisus scoparius) is an invasive shrub with polymorphism in the color of its flowers that can be yellow, orange, or red. In three areas dominated by the Scotch broom, we described the abundance of the floral morphs and estimated bumblebee (Bombus terrestris) visitation rate. We examined whether bumblebee visitation to the floral morphs was related to pollen reward. We collected flowers and classified their stamens according to their function: reward or pollen export. Then, we measured anther size and estimated pollen quantity. The yellow morph was more abundant and more visited by bumblebees than the orange and red morphs. The yellow flowers did indeed offer more pollen than the other morphs and this occurred only for rewarding anthers, suggesting that bumblebees could use yellow color as an honest signal to visit the most rewarding flowers. We discuss whether innate and/or learned preferences of bumblebees can explain why the yellow morph is more visited, pollinated, and abundant, while the other morphs are maintained at a lower frequency. This is one of the few field works that shows that variation in intra-specific floral traits is associated with variation in floral reward and pollinator visitation rate, helping to understand the foraging preferences of pollinators and the coexistence of floral morphs in nature. Clinical trials registration: Not applicable.Fil: Devegili, Andrés Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Farji Brener, Alejandro Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin

How do ideas arise?: Some suggestions to stimulate the generation of original projects in ecology

Los investigadores en ecología pretendemos desarrollar proyectos basados en ideas novedosas pero, como todos los seres humanos, tenemos una capacidad de creatividad limitada. Por ende, es común que durante nuestra vida académica se nos ocurran sólo unas pocas ideas realmente originales. Entonces, conocer cómo surgen las ideas se torna vital. Si estamos al inicio de la vida académica, nos facilitará el desarrollo de los primeros proyectos independientes, y si estamos hacia el final, puede alargar la etapa creativa de la vida profesional. En este ensayo, primero describiré algunas sugerencias para estimular la generación de proyectos originales en ecología y detallaré el contexto en el cual se gestaron. Finalmente, propondré un marco conceptual integrador cuyo uso puede estimular el surgimiento de ideas originales. En base a experiencias personales que he detallado en el texto, identifico tres aspectos que pueden estimular la creatividad: el inconformismo con las ideas dominantes, la existencia de contratiempos y la atención por lo atípico. Niveles extremos de estos aspectos son contraproducentes. Niveles mínimos de inconformismo, contratiempos o interés por lo atípico atentan contra la creatividad porque estimulan la sumisión intelectual a los paradigmas dominantes, fomentan la comodidad y promueven ceguera antes los detalles por fuera de la norma. Pero niveles muy altos también limitan la creatividad porque estimulan la crítica sin fundamentos, generan estrés permanente y estimulan el detallismo excesivo, descontextualizando un fenómeno de su entorno. En consecuencia, propongo que la generación de ideas originales se ve maximizada con niveles intermedios de inconformismo, contratiempos y atención a lo atípico. Para estimular proyectos en ecología basados en ideas originales sugiero poseer algún nivel de inconformismo sobre las ideas dominantes, considerar a los pequeños contratiempos como oportunidades y prestar atención a lo atípico sin desatender el contexto de donde provienen.Researchers in ecology try to develop projects based on novel ideas, but, as good human beings we are, we have a limited capacity for creativity. Therefore, it is usual for us, during our academic life, to generate only few really original ideas. Knowing how original ideas arise becomes vital. If we are at the beginning of our academic life, it will facilitate the development of our first independent projects; and if we are at the end of our career, it may lengthen the creative stage of our professional life. In this essay, I will first describe some suggestions to stimulate the generation of original projects in ecology, detailing the context where they were conceived. Finally, I will propose an integrative conceptual framework whose use may favor the occurrence of original ideas. Based on detailed personal experiences in the text, I identify three key aspects that may stimulate the generation of creativity: nonconformity with dominant ideas, the existence of setbacks and attention to the atypical. Extreme levels of these aspects are counterproductive. Minimal dosages of nonconformity, setbacks, or attention to the outliers undermine creativity because they stimulate conformity, comfort, and focus only on the rule. But too high levels also limit the generation of original ideas because it limit an integrative vision, causes exasperation and prevents us from seeing the phenomenon context. Consequently, I consider that the generation of original ideas is maximized with intermediate levels of nonconformity, setbacks and attention to the atypical. To stimulate ecology projects based on original ideas, I suggest having some level of nonconformity about the dominant ideas, considering small setbacks as opportunities and paying attention to the atypical without neglecting the context where they come from.Fil: Farji Brener, Alejandro Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin

To pose or not to pose hypotheses? Suggestions for students, editors and reviewers

Un objetivo fundamental de la ecología como ciencia es determinar patrones en la naturaleza e inferir sus posibles causas. Pese a la importancia y la complementariedad de las aproximaciones descriptivas y deductivas, es común que directores, revisores y organismos de financiación requieran obligatoriamente formular hipótesis en los proyectos de investigación. Dado que los avances en ecología se deben en gran medida al proceso iterativo de descripción (que no requiere la formulación de hipótesis) y de deducción, es necesario defender la diversidad de enfoques a fin de simplificar los procesos de elaborar y revisar proyectos, y de descubrir, comprender y manejar de más adecuadamente los sistemas naturales. En este ensayo se desarrollan argumentos tanto a) apoyando la no inclusión de hipótesis en los buenos estudios descriptivos o aplicados puros cuando las mismas no están justificadas de manera adecuada, como b) a favor de transformar estudios descriptivos en deductivos cuando la inclusión de hipótesis es factible, no oscurece el objetivo original del proyecto y aporta originalidad, objetividad y generalidad. Finalmente, se brindan sugerencias para autores, directores y revisores para justificar adecuadamente sus opiniones, evitar prejuzgar buenos proyectos descriptivos y realizar sugerencias constructivas y justificadas en el caso de que la inclusión de hipótesis no desvirtúe el objetivo original del trabajo, sean factibles de ponerse a prueba y su inclusión les brinde un valor agregado.A key goal of ecology as a science is to determine patterns in nature and infer their possible causes. Despite the importance and complementarity of descriptive and deductive approaches, it is common for directors, reviewers and funding agencies to compulsorily require the formulation of hypotheses in research projects. Given that advances in ecology are largely due to the iterative process of description (which does not require the formulation of hypotheses) and deduction, it is necessary to defend the diversity of approaches in order to simplify the elaboration and revision processes of projects, and to discover, understand and better manage natural systems. In this essay, arguments are developed both supporting the non-inclusion of hypotheses in descriptive or pure applied studies when they are not adequately justified, as well as in favor of transforming descriptive studies into deductive ones when the inclusion of hypotheses is feasible, does not obscure the original objective of the project and provides originality, objectivity and generality. Finally, suggestions are provided for authors, directors and reviewers to adequately justify their opinions, avoid prejudgments in the case of good descriptive projects, and make constructive and justified suggestions when the inclusion of hypotheses does not mislead the original objective of the work. are feasible to test, and their inclusion provides added value.Fil: Farji Brener, Alejandro Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin

A proposal of a conceptual framework for the development of entomology research projects and related sciences.

Planning research projects is a challenge that many students fail to successfully overcome. A lack of formal training in research planning and design, an excessive emphasis on analysis rather than on ideas and a lack of a guide are some of the possible causes of this problem. This essay proposes a conceptual framework that is of didactic utility to guide students in their research projects in entomology and related sciences. Three approximations and three approaches are presented. The proposed approximations are: descriptive, deductive observational and deductive experimental. The first is useful to design descriptive projects, where natural patterns are discovered and determined, and thus it is unnecessary and inaccurate to specify hypotheses and predictions. Deductive approximations use the hypothetical-deductive method and thus need to specify a priori the ideas being tested and the consequences if they are true. In the first deductive approximation, the predictions come from observational data, while in the second they come from experiments. Three approaches proposed are: comparative, associative and manipulative. The first two approaches can be used in both the descriptive and the deductive observational approximations. However, the manipulative approach is necessary if the experimental approximation is used. All these approximations and approaches have strengths and weaknesses; they are complementary rather than exclusive and are illustrated with an ecological study. It is expected that this conceptual framework may be a didactic and useful tool for teachers and students

Factors influencing microbial activity in dumps leaf cutter ants

La descomposición de la materia orgánica que realizan los microorganismos del suelo es vital para el funcionamiento de los ecosistemas terrestres. Nosotros usamos a los basureros de las hormigas cortadoras de hojas como un sistema modelo para determinar la influencia de la concentración y diversidad de compuestos carbonados sobre la actividad de los microorganismos descomponedores. Recolectamos muestras del basurero externo en nidos de la hormiga cortadora Acromyrmex lobicornis, en donde estimamos la concentración de compuestos carbonados y la tasa de respiración de los microorganismos.Paralelamente, estimamos la diversidad de la dieta de cada nido como una aproximación de la diversidad de compuestos orgánicos en sus basureros. La actividad de los microorganismos no dependió de la concentración de compuestos carbonados pero mostró una tendencia a depender positivamente de la diversidad de la dieta de las hormigas. Dado que la diversidad de compuestos carbonados en el basurero depende de la diversidad de las plantas cosechadas por las hormigas, estos resultados apoyan parcialmente la hipótesis que predice un aumento de la productividad ante incrementos de la diversidad por procesos de facilitación y/o complementación entre los grupos de organismos degradadores. Este trabajo ejemplifica cómo las hormigas cortadoras afectan al suelo en ambientes áridos en donde la materia orgánica es limitante; e ilustra una forma novedosa cómo la pérdida de la diversidad vegetal puede afectar indirectamente la productividad de los descomponedores al empobrecer la dieta de las hormigas.Soil microorganisms play a key role in the process of nutrient cycling. Therefore, the knowledge of the factors that influence its activity is vital for a better understanding of terrestrial ecosystem function. We use external refuse dumps from the leaf-cutting ant Acromyrmex lobicornis such as a model system to determine the influence of the concentration and diversity of organic matter on the activity of soil decomposers. We estimated the concentration of carbonate compounds and the respiration rate of microorganisms in samples of refuse dumps under lab conditions. We also estimated the diversity of the ant diet like a proxy of the diversity of organic compounds in their refuse dumps. The activity of microorganisms did not show association with the concentration of carbonate compounds, but showed a tendency to a positive association with the diversity of the ant diet. Since the diversity of organic matter in refuse dumps depends on the diversity of the plants harvested by ants, these results partially support the idea that the activity of soil microorganisms partially depends on the diversity of resources to decompose. This work exemplify how leaf-cutting ants affect soil properties in arid environments where the availability of organic matter is limiting, and illustrate a novel way how the reduction of vegetation diversity may indirectly affect the productivity of a system through the impoverish of the leaf-cutting ant´s diet.Fil: Fernandez, Anahi Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; ArgentinaFil: Farji Brener, Alejandro Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; ArgentinaFil: Satti, Patricia. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina. Universidad Nacional de Rio Negro; Argentin