Niche differences may reduce susceptibility to competition between native and non‐native birds in oceanic islands

Aim Few bird extinctions on oceanic island have been attributed to competition with non-native species, even though it might be an overlooked driver of biodiversity loss. We evaluate the potential competition between native and non-native island bird species, identifying species and island characteristics that enhance it and may promote future extinctions. Location Seventy-three (>100 km2) oceanic islands worldwide. Methods We compiled a species list for each island and used single-trait meta-analyses to assess differences between native and non-native species. Then, we used single-trait beta regression models to identify species traits linked to potential competition. Finally, we used a trait-based approach to calculate the potential competition between native and non-native species on each island and identify island characteristics linked to potential competition. Results Native bird species tended to be smaller forest dwellers, that were either carnivore, frugivore or insectivore, and that foraged in flight, in the canopy or at mid-height. In contrast, non-native birds tended to be open habitat granivores, that were either ground or unspecialized foragers. Potential competition tended to be higher for native species with typical non-native traits and forest-dwelling unspecialized non-native species. Potential competition between native and non-native birds was consistently higher in islands that were larger, had more non-native birds or were drier. Main conclusions Niche differentiation of native and non-native species may explain the scarcity of reported competition-driven extinctions since non-natives clearly tend to favour and are better adapted to anthropogenic environments. However, the few non-native birds that occur in native ecosystems may be problematic. The loss of native ecosystems coupled with the introduction of species that might outcompete native species may enhance the relevance of competition in future island extinctions.info:eu-repo/semantics/publishedVersio

Produção da videira Ruby Cabernet submetida a diferentes modalidades de colheita e sistemas de condução, no vale do Submédio São Francisco, Brasil.

A videira ?Ruby Cabernet?, originária da Califórnia, resultou do cruzamento entre Cabernet Sauvignon x Carignane. Na região do Vale do Submédio São Francisco, a produção dessa cultivar teve início na década de 80, com seu primeiro vinho varietal lançado em 2003. Essa região é pioneira na produção desse vinho varietal, no Brasil. O objetivo deste trabalho foi caracterizar o comportamento produtivo da cv. Ruby Cabernet conduzida em latada e espaldeira e submetida a diferentes modalidades de colheita. Foi utilizado um vinhedo comercial, implantado em fevereiro de 2004, sobre porta-enxerto IAC-572, com espaçamento 3,0 x 2,0 m, irrigado por gotejamento, com poda realizada em 23.11.2006. O delineamento experimental foi blocos ao acaso, com parcela subdividida e quatro repetições. Os tratamentos foram sistema de condução, sendo T1 = espaldeira; T2 = latada; e colheita selecionada, sendo C1 = colheita planta completa e C2 = colheita 2 cachos da base dos ramos, aos 144 dias após a poda (DAP); e C3 = colheita cachos restantes de C2, realizada aos 172 DAP. Os sistemas de condução foram distribuídos nas parcelas e as colheitas nas subparcelas. O sistema de condução em latada foi significativamente superior na produção (8,3 Kg/planta), no número de cachos (127) e no peso médio dos cachos (64,4 g), quando comparado com a condução em espaldeira (4,3 Kg/planta; 66 cachos; 60,1 g). Entre as modalidades de colheita, não foram observadas diferenças significativas entre a produção e o peso médio dos cachos. No entanto, em C1, o peso de 100 bagas foi maior sob espaldeira. A colheita seletiva dos cachos não implicou em redução significativa da produção total, porém o sistema de condução pode afetar a qualidade das uvas, devido às bagas maiores na espaldeira, devido à relação película/polpa, podendo alterar a qualidade e o equilíbrio dos vinhos durante o processo de vinificação

Efeito da colheita seletiva na qualidade fisico-química da cultivar Ruby Cabernet plantada em diferentes sistemas de condução no vale do Submédio São Francisco, Brasil.

Este trabalho objetivou analisar as características fisico-químicas de uvas da cv. Ruby Cabernet, colhidas em diferentes regiões da planta (colheita seletiva) e conduzidas nos sistemas latada e espaldeira

Social plasticity in the fish brain: Neuroscientific and ethological aspects

© 2019 Elsevier B.V. Social plasticity, defined as the ability to adaptively change the expression of social behavior according to previous experience and to social context, is a key ecological performance trait that should be viewed as crucial for Darwinian fitness. The neural mechanisms for social plasticity are poorly understood, in part due to skewed reliance on rodent models. Fish model organisms are relevant in the field of social plasticity for at least two reasons: first, the diversity of social organization among fish species is staggering, increasing the breadth of evolutionary relevant questions that can be asked. Second, that diversity also suggests translational relevance, since it is more likely that “core” mechanisms of social plasticity are discovered by analyzing a wider variety of social arrangements than relying on a single species. We analyze examples of social plasticity across fish species with different social organizations, concluding that a “core” mechanism is the initiation of behavioral shifts through the modulation of a conserved “social decision-making network” along with other relevant brain regions, by monoamines, neuropeptides, and steroid hormones. The consolidation of these shifts may be mediated via neurogenomic adjustments and regulation of the expression of plasticity-related molecules (transcription factors, cell cycle regulators, and plasticity products)

Water productivity in function of the regulated deficit of irrigation in the phase of maturation of grape Apirênica in the Valley of the San Francisco.

The aim of this work was to evaluate the effects o f irrigation water depths and cut-off timing in the maturation stage of Superior Seedles s grape grown in the of the San Francisco River region , to obtain simultaneously maximum yields and water use efficiency

Does undiagnosed diabetes mitigate the association between diabetes and cognitive impairment? Findings from the ELSI‐Brazil study

Background: Type 2 diabetes mellitus (T2DM) is associated with cognitive impairment. However, most of the evidence has been based on self‐reported T2DM, and undiagnosed diabetes has not been considered as a separate category. We aimed to examine the extent to which undiagnosed diabetes modifies the association between diabetes and cognitive impairment in a representative sample of Brazilian adults aged 50 years and older. / Methods: We analyzed baseline data from 1944 participants of the Brazilian Longitudinal Study of Aging (ELSI‐Brazil) conducted from 2015 to 2016. Diabetes was evaluated based on self‐reported doctor diagnosis and glycosylated hemoglobin levels. Participants were classified as diabetics (D), undiagnosed diabetics (UDD), or nondiabetics (ND). Cognitive function was assessed by word list learning and verbal fluency tests. Three multiple logistic regression models were used to evaluate the changes in the strength of the associations. / Results: Participants with diabetes had 49% greater odds of exhibiting impaired memory than nondiabetics (odds ratio [OR] = 1.49; 95% CI: 1.01‐2.20). By combining UDD and ND, the association between diabetes and impaired memory was attenuated by 2.0%, losing its statistical significance (OR = 1.46; 95% CI: 0.98‐2.17). By combining UDD and D, the association was attenuated by 7.4% (OR = 1.38; 95% CI: 1.01‐1.90). No significant association was found between T2DM and impaired verbal fluency. / Conclusion: This study found an association between T2DM and impaired memory but not with impaired verbal fluency. When UDD individuals are considered diabetics, this association is attenuated; when UDD individuals are considered as ND, this association is attenuated to the extent that it loses its statistical significance, affecting thus the clinical interpretation

Bird extinctions and introductions are causing taxonomic and functional homogenization in oceanic islands

Humans are quickly reshaping species assemblages through the loss and gain of species at multiple scales. Extinctions and introductions are non-random events known to be contributing to taxonomic homogenization. However, it is not yet clear if they also promote functional homogenization. Here, we assess whether extinctions and introductions are leading to taxonomic and functional homogenization of 64 oceanic island bird assemblages, belonging to 11 archipelagos. Based on island lists of extinct and extant, native and introduced species and on species traits, we use probabilistic hypervolumes in trait space to calculate functional beta-diversity before and after extinctions and introductions. Bird extinctions and introductions promoted taxonomic and functional homogenization on most oceanic islands. These results follow our expectations, considering previous studies on taxonomic homogenization, the predictable link between taxonomic and functional diversity, and the trait similarity of many introduced species, often adapted to anthropogenic habitats, linked to the non-randomness of bird introductions on islands. Taxonomic homogenization was more common across than within archipelagos, also corroborating previous studies describing stronger homogenization on islands that are further apart and thus had distinctive native assemblages. Surprisingly, the widespread loss of species with similar traits, namely large flightless birds, often led to functional differentiation across archipelagos. However, this differentiation effect tended to be offset by the homogenizing effect of introductions. Functional homogenization increases the vulnerability to global changes, by reducing the variability of responses to disturbance and thus the resilience of ecosystem services, posing a threat to human societies on islands. Our results highlight subtle variations in taxonomic and functional beta-diversity of bird assemblages in oceanic islands, providing important insights to allow a better assessment of how anthropogenic changes might alter ecosystem functioning, which is vital to develop effective long-term conservation strategies. Read the free Plain Language Summary for this article on the Journal blog.Peer reviewe