Neotropical Entomology 33(3): 391-393 (2004) PALAVRAS-CHAVE: Especialização de microhabitats, herbivoria, limitação no forrageamento, Serra do CipóABSTRACT -Foraging rate can directly affect the impact that Atta laevigata (Smith) has on the environment. We attempted to assess the factors which most affect foraging rate of A. laevigata using data collected over a three month period in the Parque Nacional da Serra do Cipó in Minas Gerais, Brazil. A bimodal foraging pattern was observed on clear sunny days, based on collected dry weights of vegetative material being carried towards nest entrances. Sampled entrances on clear sunny days yielded a daily average dry weight twice as high (0.9713 ± 0.1358 g) as on rainy days (0.4485 ± 0.1120 g). Larger nests (0.9713 ± 0.1358 g) yielded higher dry weights than smaller nests (0.2752 ± 0.0463 g). Field observations showed Ants switched to nest entrances with more suitable microhabitat conditions in both rainy and sunny days. A combination of temperature, humidity, nest size, and microhabitat specialization were the most important factors influencing A. laevigata foraging pattern.

The Fundão tailings dam held back approximately 50 million cubic meters of tailings from an Fe ore mine in the state of Minas Gerais, Brazil. The dam failed on 5 November 2015, releasing tailings into the Rio Doce watershed and causing an environmental disaster in a biodiversity hotspot. To guide conservation action following the event, Brazilian authorities demanded an impact assessment focused on terrestrial species threatened by extinction. Postdisaster impact assessment is substantially more challenging than predevelopment impact assessment. Predisaster baseline data were sparse, and much was unknown about how the Fundão dam failure impacted terrestrial species threatened with extinction. Baseline reconstruction and impact pathway validation and characterization was critical. Ecosystem reconstruction revealed that 1580 ha of terrestrial ecosystems were destroyed, including approximately 480 ha of Atlantic rainforest. Collaboration with local experts identified 346 species of vertebrates, invertebrates, and vascular plants threatened with extinction that were impacted or potentially impacted. Species composition and impacts varied within 4 distinct segments of the Rio Doce watershed. Nine potential impact pathways were identified using data and literature review combined with information provided by regulators, experts, and media. Not all were valid. Validating and characterizing each pathway within each watershed segment involved data evaluation, an ecological risk screening, and field assessments. Impact pathway evaluation proved critical to dispelling misconception, accurately understanding postdisaster impacts, and directing conservation action; the importance of this step cannot be overemphasized. Integr Environ Assess Manag 2020;16:676–680. © 2020 SETAC

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ResumoA viabilidade de projetos de resgate e translocação de Oncidium warmingii (Orchidaceae), uma espécie de campo rupestre ameaçada de extinção, foi avaliada segundo duas metodologias de reintrodução: a translocação direta dos indivíduos para a área de reintrodução e a translocação indireta, que consiste no cultivo prévio em casa de vegetação, antes da translocação para a área de reintrodução. As 29 plantas resgatadas foram monitoradas por 15 meses, para avaliação da sobrevivência, da taxa de crescimento em número de bulbos e da proporção de bulbos vegetativamente ativos. Ao fi nal do período de monitoramento, as plantas translocadas diretamente para a área de reintrodução apresentaram maiores índices nos três parâmetros avaliados. O método de translocação indireto mostrou-se menos efi ciente, principalmente na fase de transferência das plantas da casa de vegetação para a área de reintrodução. Tal fato indica ser necessário o emprego de técnicas de enrustecimento para garantir que as plantas se adaptem melhor ao campo, quando transferidas da casa de vegetação. De uma maneira geral, a espécie estudada demonstrou boa tolerância à translocação, tanto diretamente ao ambiente quanto com cultivo prévio em casa de vegetação. O sucesso do resgate de O. warmingii deve servir de estímulo a ações semelhantes com outras espécies endêmicas e ameaçadas, em áreas destinadas ao desenvolvimento de atividades antrópicas que resultem na supressão da vegetação nativa.Palavras-chave: espécies ameaçadas, conservação, reintrodução, orquídeas. AbstractThe viability of a program to rescue and translocate Oncidium warmingii (Orchidaceae), a rupestrian fi eld endangered species, was assessed by two reintroduction methods: direct translocation of the rescued individuals to the reintroduction site and indirect translocation, i.e., previous cultivation in a greenhouse, before translocation to the reintroduction site. 29 rescued plants were monitored for 15 months to evaluate survival, growth rate (number of bulbs), and proportion of bulbs vegetatively active. At the end of the monitoring period, the plants directly translocated to the reintroduction site had higher rates of survival, growth