El faisán plateado (Lophura nycthemera) introducido en la Patagonia: Abundancia, estructura de los grupos, patrones de actividad y asociación con el disturbio humano

Los fasiánidos son uno de los grupos de aves introducidas con mayor impacto en los ecosistemas nativos. En la Patagonia varias especies de fasiánidos están establecidas o en proceso de establecimiento, por lo que es relevante conocer sus impactos sobre los ecosistemas. El Faisán Plateado (Lophura nycthemera) fue introducido en Isla Victoria en la década de 1950 y se estableció exitosamente en toda la isla. El objetivo de este trabajo es estudiar la población de esta especie en Isla Victoria en términos de abundancia y su asociación con el disturbio humano como un primer paso para conocer su impacto potencial en el ecosistema. Se realizaron capturas fotográficas mediante fototrampeo y observaciones directas en transectas lineales ubicadas en áreas con niveles alto y bajo de disturbio humano. Con los datos de las capturas fotográficas se estimó un índice de abundancia relativa para comparar el uso de hábitat entre las dos áreas. Se utilizó la técnica de muestreo a distancia para estimar la densidad poblacional a partir de las observaciones directas. El Faisán Plateado usó más las áreas con un alto nivel de disturbio, lo que sugiere que la presencia de hábitats modificados podría facilitar su establecimiento y dispersión en la Patagonia. Las densidades poblacionales, tanto en las áreas con alto como con bajo nivel de disturbio, fueron mayores que las reportadas en su área de distribución nativa, mostrando que esta especie ha tenido un gran éxito en Isla Victoria. La alta abundancia, junto con características distintivas tales como el gran tamaño, los hábitos de alimentación y el comportamiento social, pueden moldear las interacciones con las especies nativas e influenciar su impacto sobre las comunidades nativasPhasianids are one of the groups of introduced birds with highest impact on native ecosystems. In Patagonia several phasianids are established or in process of establishment, thus it is relevant to know their impacts on ecosystems. The Silver Pheasant (Lophura nycthemera) was introduced to Isla Victoria in the 1950’s and successfully established all over the island. The aim of this work is to study the population of this species on Isla Victoria in terms of abundance and association to human disturbance as a first step to know its potential impact in the ecosystem. We conducted camera-trapping and direct observations in linear transects located in highly disturbed and in lowly disturbed areas. Using camera-trapping data we estimated an index of relative abundance to compare habitat use between areas. We used the distance-sampling approach to estimate population density with the data from direct observations. The Silver Pheasant used much more frequently areas with a high level of disturbance, suggesting that the presence of disturbed habitats could facilitate establishment and spread of this species in Patagonia. Population densities in areas with high and with low levels of disturbance were higher than those reported from the native distribution area, showing that the Silver Pheasant had a great success on Isla Victoria. The high abundance, together with distinctive characteristics such as a large body size, foraging habits and social behaviour can shape the interactions with native species and influence its impact on native communitiesFil: Martin Albarracin, Valeria Leticia. 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. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Amico, Guillermo Cesar. 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. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Nuñez, Martin Andres. 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

Uso de hospedadores por el muérdago Argentino Ligaria cuneifolia (Loranthaceae) a lo largo de su distribución geográfica

Introducción y objetivos: Ligaria cuneifolia (Loranthaceae) posee una amplia distribución desde Perú al centro de Argentina y Uruguay. Esta especie habita en tres regiones geográficas en forma disyunta a lo largo de cordillera de los Andes, las Sierras Centrales de Argentina y en el este de Sudamérica, en Uruguay y sur de Brasil. El objetivo de este trabajo fue determinar el rango de hospedadores de Ligaria cuneifolia en toda su distribución geográfica y analizar el uso de hospedadores en cada una de las regiones geográficas (Andes, Centro y Este). M&M: Se registró el uso de hospedadores de Ligaria cuneifolia y distribución geográfica en base a ejemplares depositados en herbarios. Resultados: En total se registraron 35 especies de hospedadores nativos, comprendidas en 22 géneros y 12 familias. Además se registaron 11 especies no nativas en todas las areas. Los géneros de hospedadores con mayor número de registros fueron Schinus, Prosopis, Geoffroea, Larrea y Vachellia. Conclusiones: El uso de hospedadores no estuvo directamente asociado a las áreas geográficas. La región Andes fue la que presentó una mayor diversidad de especies, géneros y familias de hospedadores.Background and aims: Ligaria cuneifolia (Loranthaceae) has a wide geographic distribution from Peru to the center of Argentina and Uruguay. It inhabits three disjunct regions, one along the Andes, Sierras Centrales of Argentina and towards the East in Uruguay and south of Brazil. The objective of this study was to determine the host range of Ligaria cuneifolia in all the distribution range; and to analyze host use in each of the geographic regions (Andes, Center and East). M&M: hosts use and geographical distribution of Ligaria cuneifolia was recorded on the basis of specimens deposited in herbaria. Results: A total of 35 native host species were recorded as hosts. In addition, 11 non-native host species were recorded in all area. The genera with higher number of records were Schinus, Prosopis, Geoffroea, Larrea y Vachellia. Conclusions: Host use was not directly related to geographic area. The Andes region was the one that had the most host diversity at the species, genera and family level.Fil: Amico, Guillermo Cesar. 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: Vidal Russell, Romina. 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

Climate change can disrupt ecological interactions in mysterious ways: Using ecological generalists to forecast community-wide effects

Ecological interactions are the backbone of biodiversity. Like individual species, interactions are threatened by drivers of biodiversity loss, among which climate change operates at a broader scale and can exacerbate the effects of land-use change, overharvesting, and invasive species. As temperature increases, we expect that some species may alter their distribution towards more amenable conditions. However, a warmer and drier climate may impose local effects on plants and animals, disrupting their interactions before noticeable changes in distribution are observed. We used a mutualistic trio from the temperate forests of South America to theoretically illustrate how climate change can disrupt ecological interactions, based on our current knowledge on this system. This study system comprises three generalist species with intersecting roles: a keystone mistletoe, a pollinator hummingbird, and a frugivorous marsupial that disperses the seeds of many species. On the one hand, drought causes water stress, increasing mortality of both mistletoe and host plants, and reducing the production of flowers and fruits. These resource shortages negatively impact animal's foraging opportunities, depleting energy reserves and compromising reproduction and survival. Finally, warmer temperatures disrupt hibernation cycles in the seed-dispersing marsupial. The combined result of these intersecting stressors depresses interaction rates and may trigger an extinction vortex if fail to adapt, with deep community-wide implications. Through negatively affecting generalist mutualists which provide resilience and stability to interaction networks, local-scale climate impacts may precipitate community-wide extinction cascades. We urge future studies to assess climate change effects on interaction networks rather than on singular species or pairwise partnerships.Fil: Fontúrbel, Francisco E.. Pontificia Universidad Católica de Valparaíso; ChileFil: Nespolo, Roberto F.. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; ChileFil: Amico, Guillermo Cesar. 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: Watson, David M.. Charles Sturt University; Australi

Do animal-plant interactions influence the spatial distribution of Aristotelia chilensis shrubs in temperate forests of southern South America?

Seed dispersal constrains the environmental heterogeneity to which a plant species is exposed through its life. Behavior of seed dispersers and seed predators could be influenced by food availability and vegetation cover. Consequently, recruitment probabilities are heterogeneous in space and time, and “regeneration windows” may appear. Aristotelia chilensis is the most abundant fleshy-fruited shrub in the temperate forest of southern South America (TFSA). TFSA exhibits an environmental patchiness that could influence fruit abundance and animal behavior. Our objective was to determine the regeneration windows of A. chilensis, and to detect how forest structure and animal behavior could affect the spatial distribution of this species. We characterized forest structure in two plots that included mature forest, young forest, and open areas. We assessed the spatio-temporal distribution of A. chilensis fruits and studied fruit removal by animals. Also, we experimentally evaluated germination and post-dispersal seed predation. We developed a conceptual model to relate A. chilensis recruitment with forest successional stages. The fruiting individuals of this shrub were mostly located in fire-opened areas or forest gaps, and the seed rain generated by the migratory bird Elaenia albiceps was denser in these areas. In contrast, seed predation by rodents was higher in closed, young forest areas. A. chilensis recruitment follows a nucleation dynamic around fruiting females. Concerning forest succession, A. chilensis recruitment was higher near re-sprouting females in open areas, and lowest in young forests, where fruiting process was hindered by light constraints. When forests mature, new nucleation processes start around females surviving in gaps. We conclude that areas opened by disturbances provide a regeneration window for A. chilensis shrubs.Fil: Bravo, Susana Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagónicas; ArgentinaFil: Cueto, Victor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagónicas; ArgentinaFil: Amico, Guillermo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentin

Node-by-node disassembly of a mutualistic interaction web driven by species introductions

Interaction webs summarize the diverse interactions among species in communities. The addition or loss of particular species and the alteration of key interactions can lead to the disassembly of the entire interaction web, although the nontrophic effects of species loss on interaction webs are poorly understood. We took advantage of ongoing invasions by a suite of exotic species to examine their impact in terms of the disassembly of an interaction web in Patagonia, Argentina. We found that the reduction of one species (a host of a keystone mistletoe species) resulted in diverse indirect effects that led to the disassembly of an interaction web through the loss of the mistletoe, two key seed-dispersers (a marsupial and a bird), and a pollinator (hummingbird). Our results demonstrate that the gains and losses of species are both consequences and drivers of global change that can lead to underappreciated cascading coextinctions through the disruption of mutualisms.Fil: Rodriguez Cabal, Mariano Alberto. University Of Tennessee; Estados Unidos. University Of British Columbia; CanadáFil: Barrios Garcia Moar, Maria Noelia. University Of Tennessee; Estados Unidos. University Of British Columbia; CanadáFil: Amico, Guillermo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Aizen, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Sanders, Nathan J.. University Of Tennessee; Estados Unidos. Natural History Museun Of Copenhague; Dinamarc

New occurrence records extend the northern distribution of Dromiciops in Argentina

En esta nota reportamos cinco nuevas localidades para el género Dromiciops, a partir de registros con trampas cámara y el hallazgo de un individuo muerto, todos provenientes de bosques de Nothofagus en la provincia del Neuquén (República Argentina). Estos nuevos registros expanden la distribución conocida del género casi 300 kilómetros al norte en su distribución en Argentina. Estas localidades corresponderían, posiblemente, a la especie D. bozinovici.In this note we report five new localities for the genus Dromiciops, based on camera trap records and the finding of a dead individual, all from Nothofagus forests in the province of Neuquén (Argentina). These new records expand the known distribution of the genus almost 300 km to the north. These localities probably correspond to the species D. bozinovici.Fil: Vazquez, Miriam Soledad. 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: Viviani, Debora. Gobierno de la Provincia de Neuquén. Dirección Provincial de Áreas Naturales Protegidas y Recursos Faunísticos; ArgentinaFil: Mora, Wenceslao. Gobierno de la Provincia de Neuquén. Dirección Provincial de Áreas Naturales Protegidas y Recursos Faunísticos; ArgentinaFil: Aubone, Mariana. Gobierno de la Provincia de Neuquén. Dirección Provincial de Áreas Naturales Protegidas y Recursos Faunísticos; ArgentinaFil: Amico, Guillermo Cesar. 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

Exotic Mammals Disperse Exotic Fungi That Promote Invasion by Exotic Trees

Biological invasions are often complex phenomena because many factors influence their outcome. One key aspect is how non-natives interact with the local biota. Interaction with local species may be especially important for exotic species that require an obligatory mutualist, such as Pinaceae species that need ectomycorrhizal (EM) fungi. EM fungi and seeds of Pinaceae disperse independently, so they may use different vectors. We studied the role of exotic mammals as dispersal agents of EM fungi on Isla Victoria, Argentina, where many Pinaceae species have been introduced. Only a few of these tree species have become invasive, and they are found in high densities only near plantations, partly because these Pinaceae trees lack proper EM fungi when their seeds land far from plantations. Native mammals (a dwarf deer and rodents) are rare around plantations and do not appear to play a role in these invasions. With greenhouse experiments using animal feces as inoculum, plus observational and molecular studies, we found that wild boar and deer, both non-native, are dispersing EM fungi. Approximately 30% of the Pinaceae seedlings growing with feces of wild boar and 15% of the seedlings growing with deer feces were colonized by non-native EM fungi. Seedlings growing in control pots were not colonized by EM fungi. We found a low diversity of fungi colonizing the seedlings, with the hypogeous Rhizopogon as the most abundant genus. Wild boar, a recent introduction to the island, appear to be the main animal dispersing the fungi and may be playing a key role in facilitating the invasion of pine trees and even triggering their spread. These results show that interactions among non-natives help explain pine invasions in our study area.Fil: Nuñez, Martin Andres. University Of Tennessee; Estados Unidos; . Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Hayward, Jeremy. State University Of New York; Estados UnidosFil: Horton, Thomas R.. State University Of New York; Estados UnidosFil: Amico, Guillermo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Dimarco, Romina Daniela. University Of Tennessee; Estados Unidos;Fil: Barrios Garcia, M. Noelia. University Of Tennessee; Estados UnidosFil: Simberloff, Daniel. University Of Tennessee; Estados Unidos

The ecology and evolution of the monito del monte, a relict species from the southern South America temperate forests

The arboreal marsupial monito del monte (genus Dromiciops, with two recognized species) is a paradigmatic mammal. It is the sole living representative of the order Microbiotheria, the ancestor lineage of Australian marsupials. Also, this marsupial is the unique frugivorous mammal in the temperate rainforest, being the main seed disperser of several endemic plants of this ecosystem, thus acting as keystone species. Dromiciops is also one of the few hibernating mammals in South America, spending half of the year in a physiological dormancy where metabolism is reduced to 10% of normal levels. This capacity to reduce energy expenditure in winter contrasts with the enormous energy turnover rate they experience in spring and summer. The unique life history strategies of this living Microbiotheria, characterized by an alternation of life in the slow and fast lanes, putatively represent ancestral traits that permitted these cold-adapted mammals to survive in this environment. Here, we describe the ecological role of this emblematic marsupial, summarizing the ecophysiology of hibernation and sociality, updated phylogeographic relationships, reproductive cycle, trophic relationships, mutualisms, conservation, and threats. This marsupial shows high densities, despite presenting slow reproductive rates, a paradox explained by the unique characteristics of its three-dimensional habitat. We finally suggest immediate actions to protect these species that may be threatened in the near future due to habitat destruction and climate change.Fil: Fontúrbel, Francisco E.. Pontificia Universidad Católica de Valparaíso; ChileFil: Franco, Lida M.. Universidad de Ibagué; ColombiaFil: Bozinovic, Francisco. Pontificia Universidad Católica de Chile; ChileFil: Quintero Galvis, Julian F.. Universidad Austral de Chile; ChileFil: Mejías, Carlos. Universidad Austral de Chile; ChileFil: Amico, Guillermo Cesar. 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: Vazquez, Miriam Soledad. 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: Sabat, Pablo. Universidad de Chile; ChileFil: Sánchez Hernández, Juan C.. Universidad de Castilla-La Mancha; EspañaFil: Watson, David M.. Charles Sturt University; AustraliaFil: Saenz Agudelo, Pablo. Universidad Austral de Chile; ChileFil: Nespolo, Roberto F.. Universidad Austral de Chile; Chil

Nest predation in Patagonian wetlands: predator assemblage and microhabitat characteristics

Multiple factors influence predation risk, ranging from habitat conditions to the composition and behaviour of predators. Although these factors are well documented for forest ecosystems, there is little evidence for wetlands, especially within Patagonia. Using artificial nests and camera traps, we documented the nest predation rates and predator assemblage of birds nesting in wetlands of the Patagonian steppe. We also determined the effect of vegetation cover on nest survival and studied the variation in predator groups according to nest placement: nests located in an open wetland, peripheral grassland to the wetland, and nests located in shrubs at different heights. We found 84% of nests failed, counting birds, mice, and armadillos as the main predators. Vegetation cover affected predation events of birds and small mammals, but not those of larger mammals. In turn, small mammals preyed on nests exclusively located in peripheral grassland, medium mammals preferred nests placed in open wetlands, and predation by birds was irrespective of open wetlands and grassland. We also found differences in nest predator assemblage between nests placed on the ground and in shrubs, with birds being the main predators of nests located above ground. These results can be attributed to differential habitat use and movement patterns specific to each predator group. Therefore, the identity, density, and behaviour of predators should be taken into account when planning conservation strategies for birds breeding in wetlands.Fil: Vazquez, Miriam Soledad. 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. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; ArgentinaFil: Amico, Guillermo Cesar. 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. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentin

Plant origin and fruit traits shape fruit removal patterns by native birds in invaded plant communities

Biotic interactions and mutualisms in particular have an important role in ecosystem structure and functioning as well as in the maintenance of biodiversity. Understanding how communities respond to the introduction of non-native species and what determines the establishment of novel interactions between native and introduced species will help in determining the potential impacts of biological invasions. The aims of this work were to assess patterns of frugivory and fruit removal in environments with invasion of non-native fleshy-fruited plants and to evaluate whether novel associations between native frugivores and non-native plants are determined by fruit traits. For this we selected eight study sites in areas with different degrees of invasion of non-native fleshy-fruited plants. In each site, we measured fruit availability and fruit traits of native and non-native plants. In addition, we conducted direct frugivory observations. We found that native and non-native fruits differed based on morphological trait variables, such as fruit weight and dimensions. Only two birds, Elaenia albiceps (smaller and migrant) and Turdus falcklandii (bigger and resident), are the main frugivorous present in the area. At the scale of the community of frugivores, neither visit nor fruit removal rates differ between natives and non-natives. However, at the species scale, while E. albiceps preferentially foraged on native plants, T. falcklandii preferred non-natives. Thus, some generalist frugivorous species like T. falcklandii can play a key role in promoting the invasion of non-native plants.Fil: Martin Albarracin, Valeria Leticia. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. 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: Amico, Guillermo Cesar. 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. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentin