45 research outputs found

    Are white storks addicted to junk food? Impacts of landfill use on the movement and behaviour of resident white storks (Ciconia ciconia) from a partially migratory population

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    Background: The migratory patterns of animals are changing in response to global environmental change with many species forming resident populations in areas where they were once migratory. The white stork (Ciconia ciconia) was wholly migratory in Europe but recently guaranteed, year-round food from landfill sites has facilitated the establishment of resident populations in Iberia. In this study 17 resident white storks were fitted with GPS/GSM data loggers (including accelerometer) and tracked for 9.1 ± 3.7 months to quantify the extent and consistency of landfill attendance by individuals during the non-breeding and breeding seasons and to assess the influence of landfill use on daily distances travelled, percentage of GPS fixes spent foraging and non-landfill foraging ranges. Results: Resident white storks used landfill more during non-breeding (20.1 % ± 2.3 of foraging GPS fixes) than during breeding (14.9 % ± 2.2). Landfill attendance declined with increasing distance between nest and landfill in both seasons. During non-breeding a large percentage of GPS fixes occurred on the nest throughout the day (27 % ± 3.0 of fixes) in the majority of tagged storks. This study provides first confirmation of year-round nest use by resident white storks. The percentage of GPS fixes on the nest was not influenced by the distance between nest and the landfill site. Storks travelled up to 48.2 km to visit landfills during non-breeding and a maximum of 28.1 km during breeding, notably further than previous estimates. Storks nesting close to landfill sites used landfill more and had smaller foraging ranges in non-landfill habitat indicating higher reliance on landfill. The majority of non-landfill foraging occurred around the nest and long distance trips were made specifically to visit landfill. Conclusions: The continuous availability of food resources on landfill has facilitated year-round nest use in white storks and is influencing their home ranges and movement behaviour. White storks rely on landfill sites for foraging especially during the non-breeding season when other food resources are scarcer and this artificial food supplementation probably facilitated the establishment of resident populations. The closure of landfills, as required by EU Landfill Directives, will likely cause dramatic impacts on white stork populations

    Using self-organizing maps to investigate environmental factors regulating colony size and breeding success of the White Stork (Ciconia ciconia)

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    We studied variations in the size of breeding colonies and in breeding performance of White Storks Ciconia ciconia in 2006–2008 in north-east Algeria. Each colony site was characterized using 12 environmental variables describing the physical environment, land-cover categories, and human activities, and by three demographic parameters: the number of breeding pairs, the number of pairs with chicks, and the number of fledged chicks per pair. Generalized linear mixed models and the self-organizing map algorithm (SOM, neural network) were used to investigate effects of biotic, abiotic, and anthropogenic factors on demographic parameters and on their relationships. Numbers of breeding pairs and of pairs with chicks were affected by the same environmental factors, mainly anthropogenic, which differed from those affecting the number of fledged chicks per pair. Numbers of fledged chicks per pair was not affected by colony size or by the number of nests with chicks. The categorization of the environmental variables into natural and anthropogenic, in connection with demographic parameters, was relevant to detect factors explaining variation in colony size and breeding parameters. The SOM proved a relevant tool to help determine actual dynamics in White Stork colonies, and thus to support effective conservation decisions at a regional scale

    Individual heterogeneity in life‐history trade‐offs with age at first reproduction in capital breeding elephant seals

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    International audienceecruitment age plays a key role in life-history evolution. Because individuals allocate limited resources among competing life-history functions, theory predicts trade-offs between current reproduction and future growth, survival and/or reproduction. Reproductive costs tend to vary with recruitment age, but may also be overridden by fixed individual differences leading to persistent demographic heterogeneity and positive covariation among demographic traits at the population level. We tested for evidence of intra- and inter-generational trade-offs and individual heterogeneity relating to age at first reproduction using three decades of detailed individual life-history data of 6,439 capital breeding female southern elephant seals. Contrary to the predictions from trade-off hypotheses, we found that recruitment at an early age was associated with higher population level survival and subsequent breeding probabilities. Nonetheless, a survival cost of first reproduction was evident at the population level, as first-time breeders always had lower survival probabilities than prebreeders and experienced breeders of the same age. However, models accounting for hidden persistent demographic heterogeneity revealed that the trade-off between first reproduction and survival was only expressed in "low quality" individuals, comprising 35% of the population. The short-term somatic costs associated with breeding at an early age had no effect on the ability of females to allocate resources to offspring in the next breeding season. Our results provide strong evidence for individual heterogeneity in the life-history trajectories of female elephant seals. By explicitly modeling hidden persistent demographic heterogeneity we show that individual heterogeneity governs the expression of trade-offs with first reproduction in elephant seals

    Quantitative tissue analyses of prostate cancer foci in an unselected cystoprostatectomy series.

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    What's known on the subject? and What does the study add? Much of our understanding of the pathological basis of prostate cancer comes from our analysis of radical prostatectomy specimens. Prostate cancer diagnosed by transrectal ultrasonography-guided biopsy is more likely to be posterior and basal in orientation rather than anterior or apical. Quantitative tissue analyses have not been undertaken both with details and in an unselected population, e.g. prostate specimens from autopsy cystoprostatectomy series from bladder cancer. Quantitative tissue analysis of incidentally detected prostate cancer such as largest cancer surface area, volume, site of origin, multifocality and laterality could be of paramount importance when trying to understand the findings of screen-detected programmes and focal therapy. Cancers were found in 30% of prostates. In the 96 prostates, 215 cancer foci were identified (mean 2.24). Prostate cancer was multifocal in 60% and bilateral in 80% of cases. The site of origin was in the peripheral and transition zone (TZ) in 75% and 25%, respectively. Overall, 90% of cancer foci were clinically insignificant with volume of <0.5 mL and no grades 4-5. In all, 75% of the cancer foci were in the peripheral zone, the remainder were within the TZ. One third of cancer foci were anteriorly located beyond the area sampled by posterior biopsies. One fifth of cancer foci were ≤6 mm of the apex. OBJECTIVE: •  To describe multifocality, volume and location of prostate cancers incidentally found in cystoprostatectomy specimens. Quantitative tissue analysis of prostate cancer in a population free of the evaluation bias associated with prostate-specific antigen level and biopsy is important as some men are likely to be offered tissue-preserving therapeutic strategies in the future. PATIENTS AND METHODS: •  Cystoprostatectomy specimens for bladder cancer from 345 consecutive patients without clinically manifest prostate cancer were included. •  Cancers were found in 104/345 (30%) of prostates. Cases with largest cancer >2 mL (eight patients) were excluded from morphometric study. Quantitative tissue analysis of 3-mm step-sectioned glands included largest cancer surface area, volume, site of origin, multifocality and laterality. RESULTS: •  In the 96 prostates, 215 cancer foci were identified (mean 2.24). Prostate cancer was multifocal in 58% and bilateral in 79% of cases. •  Of the 215 cancers, 90% were <0.5 mL and 79% <0.2 mL. Overall, 88% of cancer foci were clinically insignificant with a volume of <0.5 mL and no grades 4-5. •  In all, 75% of the cancer foci were in the peripheral zone, the remainder were within the transition zone. •  One third of cancer foci were anteriorly located beyond the area sampled by posterior biopsies. One fifth of cancer foci were ≤6 mm of the apex. •  Limitations include the fact that cystoprostatectomy cancer foci are at an earlier stage than screened-detected cancers. CONCLUSION: •  This detailed morphometric analysis of prostate cancer foci in a population that is free from the selection bias associated with screening can help inform our diagnostic and treatment strategies

    French health insurance data for chronic rhinosinusitis with nasal polyps between 2011 and 2018: A STROBE-compliant analysis

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    International audienceAims: The main aim of the present study was to report the annual volume of surgeries performed for chronic rhinosinusitis with nasal polyps (CRSwNP) in France, based on health insurance data. The secondary objectives were to describe the different characteristics of the surgeries and their complications, and to estimate the number of patients eligible for biotherapy. Material and methods: This was a descriptive observational retrospective study using data from French national health insurance databases for the period 2011–2018. Inclusion criteria comprised all hospital stays with procedures related to CRSwNP according to the French Common Classification of Medical Acts and consistent with French practices. Results: Ninety-two thousand one hundred and fourty one patients (92,141) for 92,884 admissions for CRSwNP surgery were analyzed, providing an accurate representation of CRSwNP surgery in France between 2011 and 2018. The revision surgery rate for patients operated on in 2011 was 13.0% (1,457/11,212), corresponding to an average annual rate of 1.86% over 7 years. In the 11,750 sinus surgery admissions in 2018, the complications rate was only 0.65% (77/11,750). Conclusion: Sinus surgery is safe (0.65% complications) and reliable (estimated revision rate, 5.5%: 5,078/92,884). This study provides the first evaluation of the target population for biotherapy in France

    Bet-hedging response to environmental variability, an intraspecific comparison

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    A major challenge in ecology is to understand the impact of increased environmental variability on populations and ecosystems. To maximize their fitness in a variable environment, life history theory states that individuals should favor a bet-hedging strategy, involving a reduction of annual breeding performance and an increase in adult survival so that reproduction can be attempted over more years. As a result, evolution toward longer life span is expected to reduce the deleterious effects of extra variability on population growth, and consequently on the trait contributing the most to it (e. g., adult survival in long-lived species). To investigate this, we compared the life histories of two Black-browed Albatross (Thalassarche melanophrys) populations breeding at South Georgia (Atlantic Ocean) and Kerguelen (Indian Ocean), the former in an environment nearly three times more variable climatically (e. g., in sea surface temperature) than the latter. As predicted, individuals from South Georgia (in the more variable environment) showed significantly higher annual adult survival (0.959, SE = 0.003) but lower annual reproductive success (0.285 chick per pair, SE = 0.039) than birds from Kerguelen (survival = 0.925, SE = 0.004; breeding success = 0.694, SE = 0.027). In both populations, climatic conditions affected the breeding success and the survival of inexperienced breeders, whereas the survival of experienced breeders was unaffected. The strength of the climatic impact on survival of inexperienced breeders was very similar between the two populations, but the effect on breeding success was positively related to environmental variability. These results provide rare and compelling evidence to support bet-hedging underlying changes in life history traits as an adaptive response to environmental variability
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