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Valentina Gaggini N. Emilio Baldaccini Fernando Spina Dimitri Giunchi 《Behavioral ecology and sociobiology》2010,64(8):1333-1342
Hierarchical relationships among different compass systems in long-distance migrants are still a matter for discussion because
different studies have led to highly variable and apparently contradictory results. We carried out cue-conflict experiments
during spring migration on pied flycatchers Ficedula hypoleuca (Passeriformes, Muscicapidae). Birds were exposed to a conflict between celestial and magnetic information by altering the
polarized light pattern or magnetic field. The polarization pattern was shifted (±90°) with filters, whereas the magnetic
field was altered (+90°) through Helmholtz coils. Birds were tested in modified Emlen funnels both before and after the cue
conflict; during the tests, only the natural magnetic field was available. This protocol was designed to test whether the
experimental birds recalibrated their magnetic compass on the directional information derived from the light polarization
pattern when the region near the horizon was visible during the conflict. Contrary to this expectation, we did not record
any significant shift in magnetic orientation after one or repeated exposures to the cue conflict. Our results support earlier
studies, which suggest that the magnetic field is the primary compass cue during the migratory period. 相似文献
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Lorenzo Serra Simone Pirrello Manuela Caprioli Matteo Griggio Alessandro Andreotti Andrea Romano Andrea Pilastro Nicola Saino Roberto Sacchi Paolo Galeotti Mauro Fasola Fernando Spina Diego Rubolini 《Behavioral ecology and sociobiology》2012,66(5):697-709
In seasonally fluctuating environments, timing of reproduction is a crucial determinant of fitness. Studies of birds show that late breeding attempts generally result in offspring of lower reproductive value, with lower recruitment and long-term survival prospects. Several proximate mechanisms, including a seasonal decline of immune system functioning, may lead to a seasonal decline of offspring fitness. We investigated seasonal variation in offspring quality by subjecting first- and second-brood chicks of a sexually size dimorphic species, the European starling Sturnus vulgaris, to an immune challenge with a bacterial endotoxin (LPS), and evaluated their growth and physiological response in terms of total plasma antioxidant capacity (TAC), concentration of reactive oxygen metabolites and hematocrit. LPS challenge did not affect chick growth or oxidative status. However, hematocrit of second-brood chicks was higher in LPS chicks compared to controls. Body mass halfway through the rearing period (days?8–9 post-hatching), TAC and hematocrit were lower among second- vs. first-brood chicks. Interestingly, sexual dimorphism in body mass at days?8–9 post-hatching markedly differed between broods, first-brood males being 4.7% and second-brood males 22.7% heavier than their sisters, respectively. Pre-fledging mortality occurred among second-brood chicks only and was strongly female-biased. Our findings suggest that starling chicks, even if in poor conditions, are little affected by a bacterial challenge, at least in the short-term. Moreover, our study indicates that sex differences in body size, possibly mediated by sex-specific maternal investment in egg size, may heavily impact on pre-fledging survival in a different way in the course of the breeding season, resulting in sex-specific seasonal decline of offspring fitness. Finally, we suggest that levels of circulating antioxidants should be regarded among the proximate causes of the association between timing of fledging and long-term survival in avian species. 相似文献
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Venancio Wilson Augusto Lima Rodrigues-Silva Caio Spina Mylena Diniz Vinicius Guimarães José Roberto 《Environmental science and pollution research international》2021,28(19):23742-23752
Environmental Science and Pollution Research - Benzimidazoles (BZ) are among the most used drugs to treat parasitic diseases in both human and veterinary medicine. In this study, solutions... 相似文献
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Spina Mylena Venâncio Wilson Rodrigues-Silva Caio Pivetta Rhannanda Copetti Diniz Vinicius Rath Susanne Guimarães José Roberto 《Environmental science and pollution research international》2021,28(19):24034-24045
Environmental Science and Pollution Research - Photoperoxidation (UV/H2O2) was used to degrade three of the worldwide most consumed antidepressant pharmaceuticals—bupropion, escitalopram, and... 相似文献
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