Birds in Coastal and Marine Environments

In Costa Rican coastal and marine environments (e.g., estuaries, mud- flats, islands, open ocean) 96 bird species have been recorded, 11% of the total avifauna in the country. This high diversity is primarily explained by the complex topography of the coasts, the large variety of habitats available for coastal and marine birds, and Isla del Coco, a volcanic island that includes a particular marine avifauna. The Pacific coast, including Isla del Coco, possesses a much higher diversity of birds (93 species) than the Caribbean coast (54 species). This difference is likely explained by higher fluctuation in tides, larger extension, and greater topographical complexity on the Pacific coast. There are only 15 coastal or marine birds that reproduce (but not exclusively) in the country. From a conservation perspective, coastal and marine birds have received little attention in Costa Rica. Consequently, contamination, caused by pesticides, sewage, and solid trash, and habitat destruction, due to the construction of tourist infrastructure, seriously threaten the coastal and marine avifauna in Costa Rica.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

High-Pitched Notes during Vocal Contests Signal Genetic Diversity in Ocellated Antbirds

Animals use honest signals to assess the quality of competitors during aggressive interactions. Current theory predicts that honest signals should be costly to produce and thus reveal some aspects of the phenotypic or genetic quality of the sender. In songbirds, research indicates that biomechanical constraints make the production of some acoustic features costly. Furthermore, recent studies have found that vocal features are related to genetic diversity. We linked these two lines of research by evaluating if constrained acoustic features reveal male genetic diversity during aggressive interactions in ocellated antbirds (Phaenostictus mcleannani). We recorded the aggressive vocalizations of radiotagged males at La Selva Biological Station in Costa Rica, and found significant variation in the highest frequency produced among individuals. Moreover, we detected a negative relationship between the frequency of the highest pitched note and vocalization duration, suggesting that high pitched notes might constrain the duration of vocalizations through biomechanical and/or energetic limitations. When we experimentally exposed wild radiotagged males to simulated acoustic challenges, the birds increased the pitch of their vocalization. We also found that individuals with higher genetic diversity (as measured by zygosity across 9 microsatellite loci) produced notes of higher pitch during aggressive interactions. Overall, our results suggest that the ability to produce high pitched notes is an honest indicator of male genetic diversity in male-male aggressive interactions

Seed dissemination by frugivorous birds from forest fragments to adjacent pastures on the western slope of Volcán Barva, Costa Rica

Logging, cattle raising, and agricultural activities have caused the destruction of most forested áreas in Costa Rica. In some middle and highlands the abrupt topography delayed the complete destruction of montane forest. Consequently, some fragments of almost pristine forest remain along streams that run in deep canyons. Frequently, these remnants serve as corridors between larger forested areas and as routes for movement of frugivorous birds. Eighteen bird species, e.g., Turdus plebejus, Elaenia frantzii and Ptilogonys caudatus are common dwellers of forest patches throughout the Pacific slope of the Volcán Barva. These species fly fre- quently from forest fragments to adjacent pastures. They defecated and regurgitated seeds of 28 plant species on stumps scattered on pasture areas. Isolated trees and specially the stumps are suitable microhabitats for germination of seeds and establishment of seedlings.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Manejo de solo, água, planta e resíduo para o controle da erosão e recuperação de áreas degradadas

O aumento de áreas degradadas em regiões anteriormente produtivas tem sido constatado em diferentes regiões do Brasil. A erosão tem se apresentado sob todas as suas formas (laminar, sulcos e voçorocas) comprometendo a capacidade de produção vegetativa do solo e provocando o assoreamento e a contaminação dos recursos hídricos. O presente trabalho visa apresentar, de forma sintetizada, ações de pesquisa em tecnologias para recuperação e monitoramento de diferentes ambientes degradados do Estado do Rio de Janeiro em desenvolvimento através de projetos financiados pela FAPERJ, CNPq e Programa Rio Rural. Busca-se selecionar, analisar e interpretar atributos que possam ser utilizados para classificar o estado de degradação das terras com vistas à elaboração de um protocolo para normatizar esses diagnósticos e facilitar o planejamento das ações de recuperação. Têm sido realizadas caracterizações pedológicas e geotécnicas das áreas de estudo, medições de altura, diâmetro e biomassa aérea e radicular das plantas utilizadas para revegetação, assim como coletadas amostras de sedimentos e água para avaliação das perdas por erosão superficial em parcelas modelo Wischemeyer. Foram instalados sensores com vistas ao desenvolvimento de um sistema para o monitoramento automatizado das perdas de solo e água por erosão

Emissões de metano na pecuária: conceitos, métodos de avaliação e estratégias de mitigação.

bitstream/item/37077/1/Doc-147-Emissoes-metano.pd

Elaboração e avaliação de doce cristalizado de bocaiuva.

O presente trabalho objetivou aproveitar a polpa de bocaiuva produzida pelas comunidades extrativistas do Estado de Mato Grosso do Sul para elaboração e avaliação de doce cristalizado

Processo de obtenção e avaliação química de doce cristalizado de bocaiuva.

A polpa da bocaiuva é uma excelente fonte de nutrientes como carboidratos, lipídeos, fibras, vitaminas e minerais, além de compostos com ação antioxidante como b 946;-caroteno, a 945;-tocoferol e fenóis totais. Este trabalho teve por objetivo aproveitar a polpa de bocaiuva produzida pelas comunidades extrativistas do Estado de Mato Grosso do Sul para elaboração e avaliação química de doce cristalizado. Foram testadas duas formulações de xarope: 75% de sacarose + 25% de glicose e 100% de sacarose. Os frutos foram higienizados para obtenção das lascas da polpa, as quais foram submetidas à cocção por 10 min antes da imersão em xarope a 30ºBrix. A cada 24 horas o xarope foi incrementado para 40, 50, 60 e 70ºBrix. Em seguida as lascas foram enxaguadas, drenadas e submetidas à secagem a 55ºC até teor de água de 8-9%. As lascas de polpas e os doces elaborados foram avaliados quanto aos teores de fenóis totais, taninos, atividade antioxidante e quanto à composição centesimal e valor energético total. Os compostos bioativos avaliados e a atividade antioxidante na polpa in natura são elevados. No doce cristalizado de bocaiuva, a adição de glicose/sacarose é mais eficiente na preservação destes compostos do que quando somente sacarose. O doce cristalizado contém elevado valor energético, devido principalmente a adição dos açúcares, e reduzidos teores de cinzas, proteínas e lipídeos. A elaboração de doce cristalizado de bocaiuva é uma alternativa de aproveitamento da polpa, com disponibilização de produtos artesanais com valor agregado e maior tempo de comercialização.Agroecol 2016. 1 CD-ROM. Publicado também em: Cadernos de Agroecologia, v. 11, n. 2, 2016

Myomaker and myomixer characterization in gilthead sea bream under different myogenesis conditions

Skeletal muscle is formed by multinucleated myofibers originated by waves of hyperplasia and hypertrophy during myogenesis. Tissue damage triggers a regeneration process including new myogenesis and muscular remodeling. During myogenesis, the fusion of myoblasts is a key step that requires different genes' expression, including the fusogens myomaker and myomixer. The present work aimed to characterize these proteins in gilthead sea bream and their possible role in in vitro myogenesis, at different fish ages and during muscle regeneration after induced tissue injury. Myomaker is a transmembrane protein highly conserved among vertebrates, whereas Myomixer is a micropeptide that is moderately conserved. myomaker expression is restricted to skeletal muscle, while the expression of myomixer is more ubiquitous. In primary myocytes culture, myomaker and myomixer expression peaked at day 6 and day 8, respectively. During regeneration, the expression of both fusogens and all the myogenic regulatory factors showed a peak after 16 days post-injury. Moreover, myomaker and myomixer were present at different ages, but in fingerlings there were significantly higher transcript levels than in juveniles or adult fish. Overall, Myomaker and Myomixer are valuable markers of muscle growth that together with other regulatory molecules can provide a deeper understanding of myogenesis regulation in fish

Spatial Geographic Mosaic in an Aquatic Predator-Prey Network

The geographic mosaic theory of coevolution predicts 1) spatial variation in predatory structures as well as prey defensive traits, and 2) trait matching in some areas and trait mismatching in others mediated by gene flow. We examined gene flow and documented spatial variation in crushing resistance in the freshwater snails Mexipyrgus churinceanus, Mexithauma quadripaludium, Nymphophilus minckleyi, and its relationship to the relative frequency of the crushing morphotype in the trophically polymorphic fish Herichthys minckleyi. Crushing resistance and the frequency of the crushing morphotype did show spatial variation among 11 naturally replicated communities in the Cuatro Ciénegas valley in Mexico where these species are all endemic. The variation in crushing resistance among populations was not explained by geographic proximity or by genetic similarity in any species. We detected clear phylogeographic patterns and limited gene flow for the snails but not for the fish. Gene flow among snail populations in Cuatro Ciénegas could explain the mosaic of local divergence in shell strength and be preventing the fixation of the crushing morphotype in Herichthys minckleyi. Finally, consistent with trait matching across the mosaic, the frequency of the fish morphotype was negatively correlated with shell crushing resistance likely reflecting the relative disadvantage of the crushing morphotype in communities where the snails exhibit relatively high crushing resistance