Barn owl feathers as biomonitors of mercury: sources of variation

Given their central role in mercury (Hg) excretion and suitability as reservoirs, bird feathers are useful Hg biomonitors. Nevertheless, the interpretation of Hg concentrations is still questioned as a result of a poor knowledge of feather physiology and mechanisms affecting Hg deposition. Given the constraints of feather availability to ecotoxicological studies, we tested the effect of intraindividual differences in Hg concentrations according to feather type (body vs. flight feathers), position in the wing and size (mass and length) in order to understand how these factors could affect Hg estimates. We measured Hg concentration of 154 feathers from 28 un-moulted barn owls (Tyto alba), collected dead on roadsides. Median Hg concentration was 0.45 (0.076–4.5) mg kg-1 in body feathers, 0.44 (0.040–4.9) mg kg-1 in primary and 0.60 (0.042–4.7) mg kg-1 in secondary feathers, and we found a poor effect of feather type on intra-individual Hg levels. We also found a negative effect of wing feather mass on Hg concentration but not of feather length and of its position in the wing. We hypothesize that differences in feather growth rate may be the main driver of between-feather differences in Hg concentrations, which can have implications in the interpretation of Hg concentrations in feathers. Finally, we recommend that, whenever possible, several feathers from the same individual should be analysed. The five innermost primaries have lowest mean deviations to both betweenfeather and intra-individual mean Hg concentration and thus should be selected under restrictive sampling scenarios.

O Mosteiro de São Bento de Cástris: memória e identidade

Memória e identidade encontram-se intrinsecamente ligadas ao património arquitectónico. Sensíveis ao passar do tempo, estes conceitos adaptaram-se atribuindo aos sítios novos significados. O Mosteiro de São Bento de Cástris em Évora, classificado como Monumento Nacional e sendo o primeiro mosteiro cisterciense a Sul do Tejo, foi também celeiro agrícola e mais tarde instituição de acolhimento de menores, encontra-se actualmente desocupado. Questiona-se assim, qual a actual identidade deste lugar? Através do estudo dos valores culturais materiais e imateriais do lugar, no período entre 1957 a 2016, esta investigação procurará identificar esta identidade através do registo das memórias recentes do lugar, da bibliografia específica e da análise do conjunto edificado. Considerando os princípios emanados pela UNESCO que consideram que a preservação do património deve respeitar a autenticidade e integridade dos bens culturais, que permanece na identidade registada na memória, procurouse entender a relação entre a contínua utilização do mosteiro e a estima colectiva por este património arquitectónico, essencial para a continuidade da sua identidade no futuro; The Monastery of São Bento de Cástris: Memory and Identity ABSTRACT: Memory and identity are intrinsically connected to architectural heritage. Their adaptability through time, results in the development of new meanings to the places. The Monastery of São Bento de Cástris in Évora, classified as National Heritage, the first Cistercian monastery built in the South of Portugal, was later a farm barn, a foster care institution and is now empty. Thus a question is posed: what is the current identity of this monastery? Through the study of the place’s material and immaterial cultural values, focus on the period from 1957-2016, this research aims to identify the identity based on the memories of the place, in specific bibliography, and in the analysis of the built environment. Following the UNESCO principles which consider that heritage conservation should respect the integrity and authenticity of the cultural assets, the impact of the continuous usage of the monastery was studied as a method to understand the collective esteem for this architectural heritage, which is vital to the preservation of its identity in the future.