42 research outputs found

    Bird populations most exposed to climate change are less sensitive to climatic variation

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    The phenology of many species shows strong sensitivity to climate change; however, with few large scale intra-specific studies it is unclear how such sensitivity varies over a species' range. We document large intra-specific variation in phenological sensitivity to temperature using laying date information from 67 populations of two co-familial European songbirds, the great tit (Parus major) and blue tit (Cyanistes caeruleus), covering a large part of their breeding range. Populations inhabiting deciduous habitats showed stronger phenological sensitivity than those in evergreen and mixed habitats. However, populations with higher sensitivity tended to have experienced less rapid change in climate over the past decades, such that populations with high phenological sensitivity will not necessarily exhibit the strongest phenological advancement. Our results show that to effectively assess the impact of climate change on phenology across a species' range it will be necessary to account for intra-specific variation in phenological sensitivity, climate change exposure, and the ecological characteristics of a population. Intra-specific variations may contribute to heterogeneous responses to climate change across a species' range. Here, the authors investigate the phenology of two bird species across their breeding ranges, and find that their sensitivity to temperature is uncoupled from exposure to climate change.Peer reviewe

    Extra-pair parentage and personality in a cooperatively breeding bird

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    Why so much variation in extra-pair parentage occurs within and among populations remains unclear. Often the fitness costs and benefits of extra-pair parentage are hypothesised to explain its occurrence; therefore, linking extra-pair parentage with traits such as personality (behavioural traits that can be heritable and affect reproductive behaviour) may help our understanding. Here, we investigate whether reproductive outcomes and success are associated with exploratory behaviour in a natural population of cooperatively breeding Seychelles warblers (Acrocephalus sechellensis) on Cousin Island. Exploratory behaviour correlates positively with traits such as risk-taking behaviour and activity in other wild bird species and might promote extra-pair mating by increasing the rate at which potential extra-pair partners are encountered. We therefore predicted that fast-exploring individuals would have more extra-pair offspring. There is also a potential trade-off between pursuing extra-pair parentage and mate guarding in males. We therefore also predicted that fast-exploring males would be more likely to pursue extra-pair parentage and that this would increase the propensity of their mate to gain extra-pair parentage. We found that neither the total number of offspring nor the number of extra-pair offspring were associated with a male’s or female’s exploratory behaviour. However, there was a small but significant propensity for females to have extra-pair fertilisations in pairs that were behaviourally disassortative. Overall, we conclude that, due to the small effect size, the association between exploratory behaviour and extra-pair paternity is unlikely to be biologically relevant. Significance statement: True genetic monogamy is rare, even in socially monogamous systems, and multiple factors, such as behaviour, social structure, morphology and physiology, determined by the biological system can cause variation in extra-pair parentage (EPP). Therefore, investigating the inherent differences in these factors among individuals could be informative. We investigated whether reproductive outcomes/success are associated with differences in the propensity to explore novel environments/objects in a promiscuous, island-dwelling cooperatively breeding bird, the Seychelles warbler. Our results showed that exploratory behaviour was not associated with the number of offspring produced by an individual, and thus the long-term fitness consequences of different exploratory tendencies did not differ. We also found that the propensity to engage in EPP in females was higher in dissimilar behavioural pairs, but due to the small effect size, we hesitate to conclude that there are personality-dependent mating outcomes in the population

    Bird populations most exposed to climate change are less sensitive to climatic variation

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    The phenology of many species shows strong sensitivity to climate change; however, with few large scale intra-specific studies it is unclear how such sensitivity varies over a species' range. We document large intra-specific variation in phenological sensitivity to temperature using laying date information from 67 populations of two co-familial European songbirds, the great tit (Parus major) and blue tit (Cyanistes caeruleus), covering a large part of their breeding range. Populations inhabiting deciduous habitats showed stronger phenological sensitivity than those in evergreen and mixed habitats. However, populations with higher sensitivity tended to have experienced less rapid change in climate over the past decades, such that populations with high phenological sensitivity will not necessarily exhibit the strongest phenological advancement. Our results show that to effectively assess the impact of climate change on phenology across a species' range it will be necessary to account for intra-specific variation in phenological sensitivity, climate change exposure, and the ecological characteristics of a population.Intra-specific variations may contribute to heterogeneous responses to climate change across a species' range. Here, the authors investigate the phenology of two bird species across their breeding ranges, and find that their sensitivity to temperature is uncoupled from exposure to climate change

    Aktywność biologiczna bursztynu bałtyckiego – żywicy kopalnej

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    This paper constitutes a review concerning studies on bioactivity of Baltic amber. Baltic amber (succinite) – Eocene fossil resin – is a very complicated mixture consisting of polymeric and low molecular mass components. In folk medicine, succinite is thought to be a remedy for all ailments or diseases. However, there are no scientific results confirming the assumption that succinite can positively influence human body. To confirm it indirectly, many articles examining succinite components were analyzed. Basing on them, we realized that many properties attributed to Baltic amber may originate from its components also released from its polymeric structure. Observed properties are: antioxidative activity, antimicrobial activity, antiphlogistic activity, repellent and insecticidal activity – they coincide with folk medicine applications of succinite.Artykuł stanowi przegląd literatury dotyczącej badań bioaktywności bursztynu bałtyckiego. Bursztyn bałtycki (sukcynit) – eoceńska żywica kopalna – jest skomplikowaną mieszaniną polimerów i składników małocząsteczkowych. W medycynie ludowej sukcynit używany jest jako cudowny lek na wiele dolegliwości i chorób. Brak jednak naukowych dowodów potwierdzających pozytywny wpływ sukcynitu na organizm człowieka, które uzasadniałyby stosowanie preparatów z bursztynu np. w kosmetykach. Aby pośrednio sprawdzić zasadność doniesień ludowych, przeanalizowano artykuły dotyczące aktywności biologicznej składników bursztynu bałtyckiego zakładając, że właściwości bursztynu muszą wynikać zarówno z właściwości jego składników, jak również z ich umieszczenia w polimerycznej strukturze sukcynitu. Stwierdzono, że właściwości biologiczne składników bursztynu – antyoksydacyjne, przeciwdrobnoustrojowe, przeciwzapalne, repelencyjne oraz insektobójcze mogą być uzasadnieniem doniesień medycyny ludowej o stosowaniu bursztynu

    Anti-collagenase, anti-elastase and anti-oxidant activities of extracts from 21 plants

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    BACKGROUND: Owing to their roles in tissue remodelling in health and disease, several studies have reported investigations on plant extracts as inhibitors of proteinases and as anti-oxidants. METHODS: The anti-ageing and anti-oxidant properties of 23 plant extracts (from 21 plant species) were assessed as anti-elastase and anti-collagenase activities and in selected anti-oxidant assays along with phenolic content. RESULTS: Anti-elastase activities were observed for nine of the extracts with inhibitory activity in the following order: white tea (approximately 89%), cleavers (approximately 58%), burdock root (approximately 51%), bladderwrack (approximately 50%), anise and angelica (approximately 32%). Anti-collagenase activities were exhibited by sixteen plants of which the highest activity was seen in white tea (approximately 87%), green tea (approximately 47%), rose tincture (approximately 41%), and lavender (approximately 31%). Nine plant extracts had activities against both elastase (E) and collagenase (C) and were ranked in the order of white tea (E:89%, C:87%) > bladderwrack (E:50%, C:25%) > cleavers (E:58%, C:7%) > rose tincture (E:22%, C:41%) > green tea (E:10%: C:47%) > rose aqueous (E: 24%, C:26%) > angelica (E:32%, C:17%) > anise (E:32%, C:6%) > pomegranate (E:15%, C:11%).Total phenolic content varied between 0.05 and 0.26 mg gallic acid equivalents (GAE)/mL with the exception of white tea (0.77 mg GAE/mL). For anti-oxidant assessment, the Trolox equivalent anti-oxidant capacity (TEAC) assay revealed activity for all extracts. White tea had the highest activity equivalent to approximately 21 microM Trolox for a 6.25 microg aliquot. In addition, seven extracts exhibited activities = 10 microM Trolox with witch hazel (6.25 microg = 13 microM Trolox) and rose aqueous (6.25 microg = 10 microM Trolox) showing very high activities at low concentrations. A high activity for white tea was also found in the superoxide dismutase (SOD) assay in which it exhibited ~88% inhibition of reduction of nitroblue tetrazolium. High activities were also observed for green tea (86.41%), rose tincture (82.77%), witch hazel (82.05%) and rose aqueous (73.86%). CONCLUSION: From a panel of twenty three plant extracts, some one dozen exhibit high or satisfactory anti-collagenase or anti-elastase activities, with nine having inhibitory activity against both enzymes. These included white tea which was found to have very high phenolic content, along with high TEAC and SOD activities
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