Toucans ( Ramphastidae) and hornbills ( Bucerotidae) as ant followers.

Toucans, especially species of the group Ramphastos vitellinus, occasionally follow armies of ants in tropical forests, on the look out for prey disturbed by the ants. Two methods of searching are used: examining the ground or the lianas and trunks. In contrasts, forest hornbills, (white crested hornbill Tropicranus albocristatus), frequently follow ant armies in Africa. After waiting poised in an erect position, they leap forward towards the ground or at the trunk, sometimes reaching up into the leaves.-translated by C.Wilson

Frugivory by toucans (Ramphastidae) at two altitudes in the Atlantic Forest of Brazil

Toucans are prominent components of the tropical American avifauna. Although these birds are very conspicuous, there are few ecological studies focusing on them. In this study, the diets of four sympatric toucans (Ramphastos vitellinus, R. dicolorus, Selenidera maculirostris, and Baillonius bailloni) were assessed by recording feeding bouts at two altitudes in the Atlantic Forest of southeast Brazil. Our results show that toucans are predominantly frugivorous birds (96.5% of the 289 feeding bouts were on fruits). In the lowlands (70 m elev.), only fruits (48 species, 27 families) were recorded, while in the highlands (700 m elev.), toucans were observed feeding on fruits (25 species, 22 families), flowers, leaves, and insects. Non-fruit items were recorded only in the highlands, most of them eaten by B. bailloni. Cecropia glaziovii and Euterpe edulis, two abundant plants in the highland and lowland sites, respectively, and Virola oleifera, a plant that produces lipid-rich arillate fruits, were eaten heavily by the toucans. The number of feeding bouts recorded for R. vitellinus in the lowlands was positively correlated with lipid content of the fruits eaten. The diameters of fruits eaten by toucans varied greatly (range = 0.4-25.0 mm). While the large Ramphastos species not only ate tiny fruits (e.g., Hyeronima alchorneoides) but also large ones (e.g., Virola gardneri), the toucanets ate piecemeal the large fruits that exceeded their gape width, suggesting that gape size did not limit the use of any fruit by the toucans at our study sites.

Differential seed germination of a keystone palm (Euterpe edulis) dispersed by avian frugivores

The effectiveness of seed dispersal by vertebrates has been analysed by examining both quantitative and qualitative components (Jordano & Schupp 2000, Schupp et al. 2010). While the quantitative component is relatively easily assessed in the field (e.g. visitation rate, number of fruits eaten per visit), the qualitative component (e.g. fate of dispersed seeds, seed treatment in the digestive system of the disperser) is rarely studied under natural conditions, because it is difficult to measure the effects on seeds once ingested by the dispersers (Cortes et al. 2009). © Cambridge University Press 2012.

Differential seed germination of a keystone palm (Euterpe edulis) dispersed by avian frugivores

FAPESP (BIOTA Program) [2007/03392-6, 2010/04927-3]

Contribution of woody habitat islands to the conservation of birds and their potential ecosystem services in an extensive Colombian rangeland

The conservation of birds and their habitats is essential to maintain well-functioning ecosystems including human-dominated habitats. In simplified or homogenized landscapes, patches of natural and semi-natural habitat are essential for the survival of plant and animal populations. We compared species composition and diversity of trees and birds between gallery forests, tree islands and hedges in a Colombian savanna landscape to assess how fragmented woody plant communities affect forest bird communities and how differences in habitat characteristics influenced bird species traits and their potential ecosystem function. Bird and tree diversity was higher in forests than in tree islands and hedges. Soil depth influenced woody species distribution, and canopy cover and tree height determined bird species distribution, resulting in plant and bird communities that mainly differed between forest and non-forest habitat. Bird and tree species and traits widely co-varied. Bird species in tree islands and hedges were on average smaller, less specialized to habitat and more tolerant to disturbance than in forest, but dietary differences did not emerge. Despite being less complex and diverse than forests, hedges and tree islands significantly contribute to the conservation of forest biodiversity in the savanna matrix. Forest fragments remain essential for the conservation of forest specialists, but hedges and tree islands facilitate spillover of more tolerant forest birds and their ecological functions such as seed dispersal from forest to the savanna matrix.

Evolutionary history of Ramphastos toucans: Molecular phylogenetics, temporal diversification, and biogeography

The toucan genus Ramphastos (Piciformes: Ramphastidae) has been a model in the formulation of Neotropical paleobiogeographic hypotheses. Weckstein (2005) reported on the phylogenetic history of this genus based on three mitochondrial genes, but some relationships were weakly supported and one of the subspecies of R. vitellinus (citreolaemus) was unsampled. This study expands on Weckstein (2005) by adding more DNA sequence data (including a nuclear marker) and more samples, including R v. citreolaemus. Maximum parsimony, maximum likelihood, and Bayesian methods recovered similar trees, with nodes showing high support. A monophyletic R. vitellinus complex was strongly supported as the sister-group to R. brevis. The results also confirmed that the southeastern and northern populations of R. vitellinus ariel are paraphyletic. X v. citreolaemus is sister to the Amazonian subspecies of the vitellinus complex. Using three protein-coding genes (COI, cytochrome-b and ND2) and interval-calibrated nodes under a Bayesian relaxed-clock framework, we infer that ramphastid genera originated in the middle Miocene to early Pliocene, Ramphastos species originated between late Miocene and early Pleistocene, and intra-specific divergences took place throughout the Pleistocene. Parsimony-based reconstruction of ancestral areas indicated that evolution of the four trans-Andean Ramphastos taxa (R. v. citreolaemus, R. a. swainsonii, R. brevis and R. sulfuratus) was associated with four independent dispersals from the cis-Andean region. The last pulse of Andean uplift may have been important for the evolution of R. sulfuratus, whereas the origin of the other trans-Andean Ramphastos taxa is consistent with vicariance due to drying events in the lowland forests north of the Andes. Estimated rates of molecular evolution were higher than the ""standard"" bird rate of 2% substitutions/site/million years for two of the three genes analyzed (cytochrome-b and ND2). (C) 2009 Elsevier Inc. All rights reserved.

Mechanical behavior of prosthesis in Toucan beak (Ramphastos toco)

The purpose of this study is to characterize the structure of the beak of Toco Toucan (Ramphastos toco) and to investigate means for arresting fractures in the rhinotheca using acrylic resin. The structure of the rhamphastid bill has been described as a sandwich structured composite having a thin exterior comprised of keratin and a thick foam core constructed of mineralized collagenous rods (trabeculae). The keratinous rhamphotheca consists of superposed polygonal scales (approximately 50 pm in diameter and 1 mu m in thickness). In order to simulate the orientation of loading to which the beak is subjected during exertion of bite force, for example, we conducted flexure tests on the dorso-ventral axis of the maxilla. The initially intact (without induced fracture) beak fractured in the central portion when subjected to a force of 270 N, at a displacement of 23 mm. The location of this fracture served as a reference for the fractures induced in other beaks tested. The second beak was fractured and repaired by applying resin on both lateral surfaces. The repaired maxilla sustained a force of 70 N with 6.5 mm deflection. The third maxilla was repaired similarly except that it was conditioned in acid for 60s prior to fixation with resin. It resisted a force of up to 63 N at 6 mm of deflection. The experimental results were compared with finite element calculations for unfractured beak in bending configuration. The repaired specimens were found to have strength equal to only one third of the intact beak. Finite element simulations allow visualization of how the beak system (sandwich shell and cellular core) sustains high flexural strength. (C) 2010 Elsevier B.V. All rights reserved.

Eimeria vitellini n. sp. (Apicomplexa: eimeriidae) from the brazilian toucan Rhamphastos vitellinus vitellinus Lichtenstein (Aves: Picicformes: Rhamplastidae)

Eimeria vitellini n. sp. is described from the faeces of the Rhamphastos v. vitellinus. Oocysts broadly ellipsoidal to oval (egg-shaped), 22,6 x 18.3 (20.0-25.0 x 16.3-22.5) micronm, shapeindex (length/width) 1.2 (1.1-1.1). Oocyst wall a single colourless layer about 0.5 micronm thick, becoming thinner at one ectremity, at which point the oocyst usually ruptures. No oocyst residuum, but 1 or 2 small polr bodies of about 1.0-1.5 x 0.5-1.0 micronm. Sporocysts ellongated ellipsoid (pearshaped), 14.3 x 7.5 (13.8-15.0 x 6.9-7.5) micronm, shape-index (1.9 (1.8-2.0), with a thin colourless wall bearing a very delicate Stieda body: a conspicuous sub-Stieda body is present. Sporozoites with anterior and posterior regractile bodies and strongly recurved around a bulky, compact sporocyst residuum composed of relatively fine granules and spherules.

Estudo da biomecânica oclusal e da aderência da resina acrílica auto-polimerizável (polimetilmetacrilato) em fraturas de rinoteca de tucanos (Ramphastos toco)

Esforço de tração foi aplicado perpendicularmente ao eixo do bico e para realização do ensaio foi utilizado um dinamômetro. O bico íntegro fraturou quando submetido a uma tração de 270,40 N, com deslocamento de 22,59mm. Para a fixação dos bicos fraturados foi utilizada resina acrílica e a área compreendeu uma faixa com 2,0 cm de largura. O segundo bico ensaiado apresentou resistência até 69.75 N. O bico submetido a condicionamento ácido resistiu a uma força de 63,29 N. Outros dois novos ensaios foram realizados, preenchendo-se toda a superfície da rinoteca. Aquele não submetido ao condicionamento ácido resistiu até 134,40 N e, aquele submetido ao condicionamento ácido, resistiu até 101,50 N. No presente trabalho não se observou correlação estatística e, conseqüentemente, diferença entre os procedimentos com utilização prévia de condicionamento ácido e aqueles sem a utilização do mesmo.

Origem, ramificação e distribuição da artéria celíaca no tucano-de-bico-verde (Ramphastos dicolorus Linnaeus, 1766)

O tucano-de-bico-verde (Ramphastos dicolorus) é uma ave encontrada nas florestas tropicais americanas e pertence à Ordem Piciforme, Família Ramphastidae. Neste trabalho objetivou-se descrever a origem, a ramificação e a distribuição da artéria celíaca do tucano-de-bico-verde. Foram utilizados três espécimes provenientes do Criatório Científico e Cultural de Poços de Caldas, MG (IBAMA, 2.31.94-00006), doados após óbito por causas naturais. As aves tiveram a artéria isquiática direita canulada para injeção de solução de látex corado, e após fixação em solução de formol a 10% foram dissecadas. A artéria celíaca originou-se a partir da porção descendente da aorta, emitindo como primeiro ramo colateral a artéria pró-ventricular dorsal. Esta emitiu ramos esofágicos e continuou-se como artéria gástrica dorsal, de aspecto tortuoso, terminando em anastomose com a artéria gástrica direita. Após curto trajeto, a artéria celíaca formou dois ramos colaterais, o esquerdo e o direito. O ramo esquerdo logo se ramificou formando a artéria pró-ventricular ventral com seus ramos esofágicos, artéria gástrica esquerda, que originou a artéria hepática esquerda, e finalmente a artéria gastroduodenal, que emitiu as artérias gástricas ventrais e duodenais. O ramo direito da artéria celíaca emitiu as artérias lienais e hepática direita, continuando-se como artéria pancreático-duodenal. Esta formou a artéria pilórica dorsal, duas artérias gástricas direitas, vários ramos duodenais, pancreáticos e a artéria duodeno-jejunal. Assim, a artéria celíaca nos três espécimes de tucano-de-bico-verde, exibiu um arranjo que se assemelha tanto ao descrito em aves domésticas quanto ao de aves silvestres.

Karyotypic characterization of Ramphastidae (Piciformes, Aves)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sexual dimorphism in Ramphastos toco and Ramphastos dicolorus (Piciformes, Aves)

Phenotypic sexual dimorphism seems to be rare in the Ramphastidae family, except in Pteroglossus viridis and in the genus Selenidera. Many breeders of wild birds believe that specimens of Ramphastos toco can be sexed using bill characteristics. In this study, various discriminant phenotypic variables were analyzed in birds which were sexed cytogenetically. Fifty-one specimens of R. toco and 20 R. dicolorus were studied. The statistically significant parameters which served to distinguish the sex in these species were the length of the culmen and tomium, length of the lower corneous beak and the cloaca. Using these parameters, capitive bird breeders can determine sex of R. toco specimens by phenotypic analysis and form breeding couples more quickly.

Dinâmica da troca de calor através do bico do tucano-toco, Ramphastos toco (Piciformes, Ramphastidae)

A regulação da temperatura corpórea, diante de variações da temperatura ambiente e/ou da taxa de produção de calor metabólico, envolve mecanismos reguladores da taxa de troca de calor entre o animal e o ambiente. Um destes mecanismos consiste na modulação da temperatura superficial de áreas especificas do corpo do animal, via ajustes vasomotores, que podem atuar tanto no sentido de promover a dissipação de calor (em uma situação de aumento da temperatura) quanto na retenção deste (em uma situação de queda de temperatura). Neste contexto, alguns animais exibem partes do corpo, como orelhas, membros, cauda, etc. que funcionam de maneira otimizada para realizar esta troca de calor. Nestes casos, estas partes são referidas como “janelas térmicas” e possuem em comum três características básicas: 1 - alta área superficial; 2 - baixo isolamento térmico; 3 – boa vascularização e controle do fluxo sanguineo na dependência da temperatura. Recentemente, o uso do bico como uma janela térmica foi descrito para o tucano-toco, Ramphastos toco (Aves, Ramphastidae), revelando ser esta uma estrutura com a maior capacidade de troca térmica já identificada. Naquele estudo, porém, a temperatura superficial das aves (bico) foi monitorada enquanto elas eram submetidas a mudanças bastante lentas (ao longo de várias horas) da temperatura ambiente, de forma que a dinâmica temporal da resposta exibida pelas aves permanecia ainda bastante desconhecida. Além disso, sabe-se que os membros das aves também atuam como importantes vias para troca de calor com o ambiente, e no caso do tucano toco, a regulação da temperatura superficial desses apêndices frente a variações da temperatura não tinha sido estudada. Portanto, o objetivo do presente estudo foi investigar a velocidade com que os ajustes vasomotores subjacentes à modulação... (Resumo completo, clicar acesso eletrônico abaixo)

Clytini neotropicais II (Coleoptera, Cerambycidae, Cerambycinae)

New species described and figured: Megacyllene (M.) nevermanni sp. nov. from Costa Rica (Limón); M. (M.) punensis sp. nov. from Peru (Puno); Neoclytus fraterculus sp. nov. from Venezuela (Guárico); N. zonatus from Guatemala (Alta Verapaz); N. vitellinus sp. nov. from Costa Rica (Guanacaste); Mecometopus erratus sp. nov. from Colombia (Boyacá); M. latithorax sp. nov. from Panama (Panama).