435 research outputs found

    Pheomelanin-based colouration is correlated with indices of flying strategies in the barn owl

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    Resource polymorphism refers to individuals from the same population foraging in alternative habitats or on alternative food. Food specialization can be associated with adaptations such as colour polymorphism, with pale and dark colours conferring differential camouflage in different habitats. Pale and dark-reddish pheomelanic Barn Owls (Tyto alba) forage on different prey species in closed and open habitats, respectively. We show here that darker-reddish owls have heavier stomach content when found dead, and their 5th secondary wing feather is more deeply anchored inside the integument. These correlations suggest that their feathers bend less when flying, and that darker-reddish Barn Owls are able sustain more intense flying than their paler conspecifics

    Safflower (\u3ci\u3eCarthamus tintorius\u3c/i\u3e): A Promising Forage Crop for Semi-Arid Regions

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    The yield, quality, preservation and intake of safflower hay were determined in two successive years - 1998 and 1999. Field experiments carried out at the Bet Dagan experimental station on the coastal plain of Israel under rain-fed conditions. A spineless variety was tested under three sowing dates. Yield decreased and quality improved as the sowing date receded from November 12 to February 3. Respective yields, IVDMD and CP content were: 22 and 8 ton DM/ha, 48.9% and 65.5% , 10.0% and 14.6%. Safflower at 290, 410 and 770 g/kg DM was ensiled in 1.5-l anaerobic glass jars with or without Lactobacillus plantarum applied at 106 cfu/g. Good-quality silages were obtained at 290 and 410 g/kg DM. The pH of the inoculated silages was 3.9-4.0 as compared to 4.7 in the control silages; the former contained more lactic acid than the controls. All silages were stable upon aerobic exposure. Inoculation with Lactobacillus plantarum improved the ensiling fermentation, and these silages, too, were stable upon aerobic exposure. Feeding experiments with heifers were conducted with safflower hay. The intake and performance of heifers fed with 25 or 50% safflower hay (DM basis) did not differ from those animals fed a control diet (no safflower in diet)

    Relationship between diet and reproductive success in the Israeli barn owl

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    The effect of diet on barn owl (Tyto alba) breeding biology has been well studied in the temperate regions but not in the more arid Middle East. In temperate regions, barn owls are darker colored and mainly prey upon Cricetidae rodents, whereas in arid regions, they are lighter colored and prey to a larger degree upon Muridae rodents. In this study we analyzed the diet and breeding success of 261 barn owl pairs nesting in Israel. The reproductive success of barn owls declined from March to August, and fledged more young when they consumed a larger proportion of social voles (Microtus socialis guentheri). Although the diet of the lighter colored barn owls in Israel comprises more Muridae than that of the darker morphs in temperate regions, in both regions the number of barn owl young increases with an increased proportion of voles in the diet

    Relationship between diet and reproductive success in the Israeli barn owl

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    The effect of diet on barn owl (Tyto alba) breeding biology has been well studied in the temperate regions but not in the more arid Middle East. In temperate regions, barn owls are darker colored and mainly prey upon Cricetidae rodents, whereas in arid regions, they are lighter colored and prey to a larger degree upon Muridae rodents. In this study we analyzed the diet and breeding success of 261 barn owl pairs nesting in Israel. The reproductive success of barn owls declined from March to August, and fledged more young when they consumed a larger proportion of social voles (Microtus socialis guentheri). Although the diet of the lighter colored barn owls in Israel comprises more Muridae than that of the darker morphs in temperate regions, in both regions the number of barn owl young increases with an increased proportion of voles in the diet

    Conditional association between melanism and personality in Israeli barn owls

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    Capsule Boldness defines the extent to which animals are willing to take risks in the presence of a predator. Late, but not early, in the breeding season, Israeli nestling Barn Owls displaying larger black feather spots were more docile, feigned death longer and had a lower breathing rate when handled than smaller-spotted nestlings. Larger-spotted breeding females were less docile if heavy but more more docile if light. The covariation between personality (boldness vs. timid) and melanin-based colouration is therefore conditional on environmental factors

    Soaring migrants flexibly respond to sea-breeze in a migratory bottleneck: using first derivatives to identify behavioural adjustments over time.

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    Millions of birds travel every year between Europe and Africa detouring ecological barriers and funnelling through migratory corridors where they face variable weather conditions. Little is known regarding the response of migrating birds to mesoscale meteorological processes during flight. Specifically, sea-breeze has a daily cycle that may directly influence the flight of diurnal migrants. We collected radar tracks of soaring migrants using modified weather radar in Latrun, central Israel, in 7 autumns between 2005 and 2016. We investigated how migrating soaring birds adjusted their flight speed and direction under the effects of daily sea-breeze circulation. We analysed the effects of wind on bird groundspeed, airspeed and the lateral component of the airspeed as a function of time of day using Generalized Additive Mixed Models. To identify when birds adjusted their response to the wind over time, we estimated first derivatives. Using data collected during a total of 148 days, we characterised the diel dynamics of horizontal wind flow relative to the migration goal, finding a consistent rotational movement of the wind blowing towards the East (morning) and to the South-East (late afternoon), with highest crosswind speed around mid-day and increasing tailwinds towards late afternoon. Airspeed of radar detected birds decreased consistently with increasing tailwind and decreasing crosswinds from early afternoon, resulting in rather stable groundspeed of 16-17 m/s. In addition, birds fully compensated for lateral drift when crosswinds were at their maximum and slightly drifted with the wind when crosswinds decreased and tailwinds became more intense. Using a simple and broadly applicable statistical method, we studied how wind influences bird flight through speed adjustments over time, providing new insights regarding the flexible behavioural responses of soaring birds to wind conditions. These adjustments allowed the birds to compensate for lateral drift under crosswind and reduced their airspeed under tailwind. Our work enhances our understanding of how migrating birds respond to changing wind conditions during their long-distance journeys through migratory corridors

    Correlative Aspects of Imposition of Dormancy in Caryopses of Aegilops kotschyi

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    The association between mental health trajectories and somatic symptoms following a second lockdown in Israel : a longitudinal study

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    Objectives To identify mental health prospective trajectories before and after a second lockdown during the COVID-19 pandemic and their associations with somatic symptoms. Design Prospective Study. Setting Population-based study drawn from a probability-based internet panel of over 100 000 Israelis. Participants Adults aged 18 years or more, representative of the adult Israeli population. The participants were measured at two time points (time 1 (T1) pre-second lockdown N=1029; response rate=76.17%; time 2 (T2) post-second lockdown N=764; response rate=74.24%). Main outcome measures Trajectories of anxiety and adjustment disorder based on clinical cut-off score for probable diagnoses across T1-T2, somatic symptoms at T2. The four trajectories: stable-low, (no probable diagnosis), stable-high (stable probable diagnosis), exacerbation (no probable diagnosis at T1, probable diagnosis at T2), recovery (probable diagnosis at T1, no probable diagnosis at T2). Results Three anxiety trajectories predicted probable somatic symptoms (stable-high OR=6.451; exacerbation OR=5.379; recovery OR=2.025) compared with the stable-low trajectory. The three adjustment disorder trajectories also predicted somatic symptoms (stable-high OR=4.726; exacerbation OR=6.419; recovery OR=4.666) compared with the stable-low trajectory. Conclusions Our data show elevated somatic symptoms among those whose mental health trajectories were poor, exacerbated and those who recovered following the second lockdown. The presentation of somatic symptoms may mask psychological vulnerabilities, even among those who appear to have recovered from the stressor. This indicates that lockdown may be a double-edged sword and should be carefully administered given these populations vulnerabilities

    The Ukraine-Russia war : a symptoms network of complex posttraumatic stress disorder during continuous traumatic stress

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    Objective: This study is aimed to test the symptoms network of ICD-11 Complex Post-traumatic Stress Disorder (CPTSD) symptoms, using data collected from Ukrainian civilians during the 2022 Russia-Ukraine war. Findings can inform our understanding of the stress response in individuals exposed to continuous trauma and give insight into the nature of CPTSD during war. Methods: A network analysis was conducted on CPTSD symptoms as assessed by the International Trauma Questionnaire using data from a nationally representative sample of 2000 Ukrainians. Results: While Post-traumatic Stress Disorder (PTSD) and Disturbances in Self Organization (DSO) clusters did not enmesh, several communities within these clusters were merged. Results highlight that in terms of strength centrality, emotional dysregulation (emotional numbing) and a heightened sense of threat were most prominent. Conclusion: The results confirm the ICD-11 structure of CPTSD but suggest that continuous traumatic stress manifests in more condensed associations between CPTSD symptoms and that emotional regulation may play a vital role in activating the CPTSD network. War-exposed populations could be provided with scalable, brief self-help materials focused on fostering emotion regulation and sense of threat
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