Moluscos holocênicos em sedimentos lagunares associados à barreira arenosa da Pinheira-Guarda-Gamboa, Santa Catarina: implicações paleoambientais

This paper documents the occurrence of mollusk carbonate fossils in sediments of the backbarrier of the Pinheira-Guarda- -Gamboa beaches, Santa Catarina Coastal Plain, southern Brazil, in which five species of gastropods and nine of bivalves were recognized. Among the bivalves, four species were articulated, Ostrea equestris, Anomalocardia brasiliana, Lucina pectinata and Tagelus plebeius, and the last three were found in life position. Radiocarbon datings were performed on articulate and life position specimens: Lucina pectinata, indicating a conventional age of 5.260 ± 30 years BP. (calibrate age 5.620 - 5.440), Tagelus plebeius, 5.620 ± 30 years BP. (calibrate age 6.000 - 5.840) and Ostrea equestris articulate, 5.410 ± 30 years BP. (calibrate age 5.805 - 5.580), indicating the material in the middle Holocene. The topographic data gathered with precision equipment established that the top of the outcrop is 2 m above the relative sea-level. The fossil association suggests lagoon-estuarine environment subsequently filled in response to a lowering of the sea level.Este trabalho documenta a ocorrência de moluscos fósseis carbonáticos em sedimentos da retrobarreira das praias da Pinheira-Guarda-Gamboa, Planície Costeira de Santa Catarina, sul do Brasil, onde foram reconhecidas cinco espécies de gastrópodes e nove de bivalves. Dentre os bivalves, identificaram-se quatro espécies articuladas, Ostrea equestris, Anomalocardia brasiliana, Lucina pectinata e Tagelus plebeius, as três últimas registradas em posição de vida. Datações radiocarbônicas foram realizadas em espécimes articulados e em posição de vida: Lucina pectinata apontando idades convencionais de 5.260 ± 30 anos AP (idade calibrada 5.620 - 5.440), Tagelus plebeius, 5.620 ± 30 anos AP (idade calibrada 6.000 - 5.840) e Ostrea equestris apenas articulado, 5.410 ± 30 anos AP (idade calibrada 5.805 - 5.580), posicionando o material no Holoceno médio. O dado topográfico com equipamento de precisão estabeleceu que o topo do afloramento encontra- -se a 2 m acima do nível relativo atual do mar. A associação indica um ambiente lagunar-estuarino, posteriormente colmatado como resposta ao rebaixamento do nível do mar

Recomendação de Cultivo da Tangerineira 'Owari' no Rio Grande do Sul.

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Exploiting Antipredator Behavior in White-Tailed Deer for Resource Protection

Effects of visual obstruction on white-tailed deer (Odocoileus virginianus) include enhanced vigilance and flight-initiation distances. Prior work suggests that artificial visual barriers might enhance perceived risk of predation to deer. During 2008–2010 at the National Aeronautics and Space Administration’s Plum Brook Station (Erie County, OH), we tested the hypotheses that visual obstruction of winter feeding stations would result in fewer white-tailed deer visiting treatment stations and increased vigilance exhibited relative to deer using control stations. When feeding stations were bounded on 3 sides by a 22.5-m-long, 1.5-m-high, continuous, polyethylene visual barrier (including a 5-m opening on the fourth side), and offset from the food resource by 22.5 m, we observed no differences in deer use or vigilance compared with control stations (4.5-cm mesh, snow fencing only). In a second experiment, feeding stations bounded by individual, 1.5-m-high, polyethylene visual barriers, positioned on 3 sides only and offset from the food resource by only 7.6 m each, were characterized by 1) fewer deer, 2) increased alert behavior (e.g., head held above horizontal, ears erect, body posture noticeably stiff and animal paused, directed attention, tail flagging, or fleeing) by deer using the stations, and 3) fewer deer using stations at night, relative to control stations. Visual barriers offset at most by 7.6 m from a food resource (e.g., crops), or located randomly within target areas frequented by deer can offer temporary and easily manipulated means of diminishing deer use of resources on unfenced General Aviation airports or depredation of agricultural crops, and ready integration with other management methods. Published 2012. This article is a U.S. Government work and is in the public domain in the USA

Pollination of Habenaria pleiophylla Hoehne & Schlechter (Orchidaceae) by Heliconius erato phyllis Fabricius (Lepidoptera, Nymphalidae)

For the first time the pollination of a poorly known, terrestrial orchid, Habenaria pleiophylla Hoehne & Schlechter, 1921 (Orchidaceae) by a passion vine butterfly, Heliconius erato phyllis (Fabricius, 1775) (Lepidoptera, Nymphalidae) is reported. Number of pollinia-carrying individuals was determined on a population of H. erato phyllis in Horto Florestal Barba Negra, Barra do Ribeiro County, Rio Grande do Sul State. The pollination mechanism was described under laboratory conditions, in association with the butterfly feeding habit and the orchid flower morphology. Habenaria pleiophylla pollinia are cemented during nectar feeding on the ventral portion of the compound eyes near H. erato phyllis proboscis base. The pollinia are transferred to the stigma of other flowers during subsequent visits. Both males and females of H. eralo phyllis frequently visit H. pleiophylla flowers in the Barba Negra Forest. About forty percent of field collected adults had attached pollinia, ranging in number from one to 19 per individual. Thus, H. eralo phyllis may play an important role in the reproductive biology of this H. pleiophylla population