Papers by Jeferson Vizentin-Bugoni
Ararajuba
ResuMo: Novos registros documentados de duas espécies de aves no extremo sul do Brasil, incluindo... more ResuMo: Novos registros documentados de duas espécies de aves no extremo sul do Brasil, incluindo a primeira menção de Agriornis murinus para o país e comentários sobre vagância. Um indivíduo de Porphyrio flavirostris foi capturado na cidade de Pelotas, Rio Grande do Sul, em 03 de outubro de 2008. Este registro, documentado através de fotografia, comprova a ocorrência dessa espécie no estado. Um espécime de Agriornis murinus, observado e fotografado junto ao litoral em Rio Grande, Rio Grande do Sul, em 25 de abril e avistado novamente em 29 de julho de 2009, constitui o primeiro registro da espécie e do gênero para o Brasil. Utilizando informações previamente publicadas e avaliando a distribuição geográfica dessas espécies, inferimos que ambos os registros são mais parcimoniosamente associados à vagância do que pseudo-vagância.
Anais da Academia Brasileira de Ciências, 2015
Hummingbirds are the most important and specialized group of pollinating birds in the Neotropics ... more Hummingbirds are the most important and specialized group of pollinating birds in the Neotropics and their interactions with plants are key components to many communities. In the present study we identified the assemblage of plants visited by hummingbirds and investigated the temporal availability of floral resources in an area of restinga, sandy plain coastal vegetation associated with the Atlantic forest, in Southeastern Brazil. We recorded flower and nectar features, flowering phenology and interactions between plants and hummingbirds and estimated the amount of calories produced per hectare from June 2005 to August 2006. Ten plant species were visited by two hummingbirds,Amazilia fimbriata and Eupetomena macroura. Resource availability was highly variable among plant species and over time. Nectar volume and concentration per flower were similar to other Neotropical hummingbird-visited plant assemblages. The estimated nectar resource availability between months varied from 0.85 to 5.97 Kcal per hectare/day, demanding an area between one and 6.8 ha to support a single hummingbird. Our study reports an unusual tropical setting where almost all interactions between hummingbirds and plants were performed by a single hummingbird species,A. fimbriata. Hence, the variable nectar availability is probably influencing hummingbird movements, its foraging area, and consequently plant pollination.
Diversity and Distributions, 2016
Proceedings of the Royal Society B: Biological Sciences, 2016
Ecological communities that experience stable climate conditions have been speculated to preserve... more Ecological communities that experience stable climate conditions have been speculated to preserve more specialized interspecific associations and have higher proportions of smaller ranged species (SRS). Thus, areas with disproportionally large numbers of SRS are expected to coincide geographically with a high degree of community-level ecological specialization, but this suggestion remains poorly supported with empirical evidence. Here, we analysed data for hummingbird resource specialization, range size, contemporary climate, and Late Quaternary climate stability for 46 hummingbird-plant mutualistic networks distributed across the Americas, representing 130 hummingbird species (ca 40% of all hummingbird species). We demonstrate a positive relationship between the proportion of SRS of hummingbirds and community-level specialization, i.e. the division of the floral niche among coexisting hummingbird species. This relationship remained strong even when accounting for climate, furthermore, the effect of SRS on specialization was far stronger than the effect of specialization on SRS, suggesting that climate largely influences specialization through species' range-size dynamics. Irrespective of the exact mechanism involved, our results indicate that communities consisting of higher proportions of SRS may be vulnerable to disturbance not only because of their small geographical ranges, but also because of their high degree of specialization.
Journal of Animal Ecology, 2015
Virtually all empirical ecological interaction networks to some extent suffer from undersampling.... more Virtually all empirical ecological interaction networks to some extent suffer from undersampling. However, how limitations imposed by sampling incompleteness affect our understanding of ecological networks is still poorly explored, which may hinder further advances in the field. Here, we use a plant-hummingbird network with unprecedented sampling effort (2,716 hours of focal observations) from the Atlantic Rainforest in Brazil, to investigate how sampling effort affects the description of network structure (i.e. widely used network metrics) and the relative importance of distinct processes (i.e. species abundances vs traits) in determining the frequency of pairwise interactions. By dividing the network into time slices representing a gradient of sampling effort, we show that quantitative metrics, such as interaction evenness, specialization (H2 '), weighted nestedness (wNODF) and modularity (Q; QuanBiMo algorithm), were less biased by sampling incompleteness than binary metrics. Furthermore, the significance of some network metrics changed along the sampling effort gradient. Nevertheless, the higher importance of traits in structuring the network was apparent even with small sampling effort. Our results (i) warn against using very poorly sampled networks as this may bias our understanding of networks, both their patterns and structuring processes, (ii) encourage the use of quantitative metrics little influenced by sampling when performing spatio-temporal comparisons, and (iii) indicate that in networks strongly constrained by species traits, such as plant-hummingbird networks, even small sampling is sufficient to detect their relative importance for the structure of interactions. Finally, we argue that similar effects of sampling are expected for other highly specialized subnetworks. This article is protected by copyright. All rights reserved.
Journal of Ornithology, 2015
Processos biogeográficos, neutros e de nicho estruturam as interações planta-polinizador. Neste c... more Processos biogeográficos, neutros e de nicho estruturam as interações planta-polinizador. Neste capítulo, revisamos as principais abordagens para a compreensão destas interações nas comunidades: 1) composição de espécies e suas interações, 2) fenótipos florais e de grupos funcionais de polinizadores, 3) grau de especialização-generalização, 4) padrões de distribuição de recursos e 5) redes de interações. Os estudos geralmente englobam subconjuntos de plantas associadas a um grupo de polinizadores. Os padrões aparentemente são determinados por competição e facilitação mas as evidências são predominantemente hipotéticas. Visando estimular estudos, propomos predições da estruturação filogenética e funcional de plantas e polinizadores e do grau de conservação filogenética de atributos reprodutivos das plantas esperados por diferentes processos. Concluímos que a compreensão da estrutura e dinâmica das interações sobre a perspectiva de regras de montagem é um passo crucial para conservaçã...
Global Ecology and Biogeography, 2015
ABSTRACT
Check List, 2015
The Reserva Biológica do Mato Grande encompasses 5,161 hectares of wetlands, restinga forests and... more The Reserva Biológica do Mato Grande encompasses 5,161 hectares of wetlands, restinga forests and grasslands in southern Brazil. Aiming to assemble a list of bird species occurring in the reserve, we carried out 21 monthly expeditions from July 2007 to March 2009 and an additional visit on October 2014, totaling 341 hours of sampling. We additionally searched for records in online databases and museums. In total, 211 species of birds were found, compared to 223.83 (SD = 3.88) and 214.68 (SD = 4.71) species respectively predicted through Jackknife 2 and Chao 2 estimations. Plegadis chihi was the most abundant bird roosting in the reserve. The area is important for the conservation of Circus cinereus, Spartonoica maluroides, Limnoctites rectirostris and Sporophila palustris, which are considered threatened or near-threatened in state, national and/ or global levels. We emphasize the urgent need of implementing the Reserva Biológica do Mato Grande in order to conserve the regional avifauna.
Acta Botanica Brasilica, 2015
Oecologia, 2015
Interactions between flowers and their visitors span the spectrum from mutualism to antagonism. T... more Interactions between flowers and their visitors span the spectrum from mutualism to antagonism. The literature is rich in studies focusing on mutualism, but nectar robbery has mostly been investigated using phytocentric approaches focused on only a few plant species. To fill this gap, we studied the interactions between a nectar-robbing hermit hummingbird, Phaethornis ruber, and the array of flowers it visits. First, based on a literature review of the interactions involving P. ruber, we characterized the association of floral larceny to floral phenotype. We then experimentally examined the effects of nectar robbing on nectar standing crop and number of visits of the pollinators to the flowers of Canna paniculata. Finally, we asked whether the incorporation of illegitimate interactions into the analysis affects plant-hummingbird network structure. We identified 97 plant species visited by P. ruber and found that P. ruber engaged in floral larceny in almost 30 % of these species. Nectar robbery was especially common in flowers with longer corolla. In terms of the effect on C. paniculata, the depletion of nectar due to robbery by P. ruber was associated with decreased visitation rates of legitimate pollinators. At the community level, the inclusion of the illegitimate visits of P. ruber resulted in modifications of how modules within the network were organized, notably giving rise to a new module consisting of P. ruber and mostly robbed flowers. However, although illegitimate visits constituted approximately 9 % of all interactions in the network, changes in nestedness, modularity, and network-level specialization were minor. Our results indicate that although a flower robber may have a strong effect on the pollination of a particular plant species, the inclusion of its illegitimate interactions has limited capacity to change overall network structure.
O Brasil possui 1.834 espécies de aves e encontra-se entre os três países do mundo com a maior ri... more O Brasil possui 1.834 espécies de aves e encontra-se entre os três países do mundo com a maior riqueza de avifauna. Destas, 234 ocorrem exclusivamente em território brasileiro. Do total de espécies de aves que ocorrem no país, 160 constam na Lista Oficial da Fauna Brasileira Ameaçada de Extinção, sendo 15 destas passeriformes ameaçados de extinção registrados nos Campos Sulinos e Espinilho. Os Campos Sulinos são ecossistemas naturais com alta diversidade de espécies vegetais e animais. São os campos dos biomas Pampa e Mata Atlântica que se estendem sobre amplas regiões do Brasil, Uruguai e Argentina. É responsabilidade do governo brasileiro, por intermédio do Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio), o desenvolvimento de estratégias para conhecer e proteger esta riqueza, além de recuperar aquelas espécies ameaçadas de extinção, por meio de diversas medidas, incluindo a elaboração e execução de planos de ação, conforme estabelecido pela Portaria ICMBio nº 78/2...
Biotropica, 2014
Complex networks of species interactions might be determined by species traits but also by simple... more Complex networks of species interactions might be determined by species traits but also by simple chance meetings governed by species abundances. Although the idea that species traits structure mutualistic networks is appealing, most studies have found abundance to be a major structuring mechanism underlying interaction frequencies. With a well-resolved plant-hummingbird interaction network from the Neotropical savanna in Brazil, we asked whether species morphology, phenology, nectar availability and habitat occupancy and/or abundance best predicted the frequency of interactions. For this, we constructed interaction probability matrices and compared them to the observed plant-hummingbird matrix through a likelihood approach. Furthermore, a recently proposed modularity algorithm for weighted bipartite networks was employed to evaluate whether these factors also scale-up to the formation of modules in the network. Interaction frequencies were best predicted by species morphology, phenology and habitat occupancy, while species abundances and nectar availability performed poorly. The plant-hummingbird network was modular, and modules were associated to morphological specialization and habitat occupancy. Our findings highlight the importance of traits as determinants of interaction frequencies and network structure, corroborating the results of a previous study on a plant-hummingbird network from the Brazilian Atlantic Forest. Thus, we propose that traits matter more in tropical plant-hummingbird networks than in less specialized systems. To test the generality of this hypothesis, future research could employ geographic or taxonomic cross-system comparisons contrasting networks with known differences in level of specialization.
Proceedings of the Royal Society B: Biological Sciences, 2014
Check List, 2011
The Hepatic Tanager Piranga flava (Vieillot, 1822) is considered rare in southern Brazil and its ... more The Hepatic Tanager Piranga flava (Vieillot, 1822) is considered rare in southern Brazil and its occurrence in southeastern Rio Grande do Sul is controversial. Here, our aims were to investigate and compile the historical and recent evidences of the species in this region by consulting museums, literature and providing documented recent records. We confirmed the origins of two old specimens and provided nineteen recent records obtained in five sites between 2008 and 2010. Our results show that Piranga flava occurs in southeastern of Rio Grande do Sul since the late 1800s and currently may be found all year long in this region.
Bird Conservation International, 2013
The Marsh Seedeater Sporophila palustris is one of the most endangered and least known of the cap... more The Marsh Seedeater Sporophila palustris is one of the most endangered and least known of the capuchino seedeaters. Breeding populations are patchy, occurring in north-east Argentina, southern Brazil, and Uruguay. We present data on the breeding biology of the species, and describe nests and eggs, behaviour (including courtship, nesting, incubation and parental care), breeding sites and food items. Marsh Seedeaters breed in well-preserved grasslands with wet soils and tall vegetation. In general, these habitats are used for extensive livestock ranching. Main threats are overgrazing, widespread use of fire, conversion of grasslands to pastures of exotic grasses and rice fields, afforestation, and illegal trapping. Most breeding sites are located in Important Bird Areas, but only one in Brazil and one in Argentina are protected. We propose a series of actions to promote the conservation of Marsh Seedeaters and other endangered birds that coexist in grassland habitats.
Revista Brasileira De Ornitologia, Apr 1, 2010
ResuMo: Novos registros documentados de duas espécies de aves no extremo sul do Brasil, incluindo... more ResuMo: Novos registros documentados de duas espécies de aves no extremo sul do Brasil, incluindo a primeira menção de Agriornis murinus para o país e comentários sobre vagância. Um indivíduo de Porphyrio flavirostris foi capturado na cidade de Pelotas, Rio Grande do Sul, em 03 de outubro de 2008. Este registro, documentado através de fotografia, comprova a ocorrência dessa espécie no estado. Um espécime de Agriornis murinus, observado e fotografado junto ao litoral em Rio Grande, Rio Grande do Sul, em 25 de abril e avistado novamente em 29 de julho de 2009, constitui o primeiro registro da espécie e do gênero para o Brasil. Utilizando informações previamente publicadas e avaliando a distribuição geográfica dessas espécies, inferimos que ambos os registros são mais parcimoniosamente associados à vagância do que pseudo-vagância.
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Papers by Jeferson Vizentin-Bugoni