Morphology and biomechanics of the nests of the Common Blackbird Turdus merula

Capsule Common blackbirds select different materials, with varying biomechanical properties, to construct different parts of their nest. Aims This study tested the hypothesis that outer components of a nest have a more structural role and so are stronger than materials used to line the cup. Methods Blackbird nests were measured prior to being dismantled to isolate structural components which were tested for mechanical strength and rigidity. Results Outer nest wall materials were significantly thicker, stronger and more rigid than materials in the inner structural wall or the cup lining. In the vertical plane materials used in the structural wall did not differ. By contrast, lining materials from the bottom of the nest cup were significantly thicker, stronger and more rigid than materials from the top of the cup. Conclusion Blackbirds use different materials in nest construction roles suited to their properties and so may be able to recognise the structural properties of these materials. Materials on the outside of the nest may have a key structural role during construction

Use of materials in nest construction by Pied Flycatchers Ficedula hypoleuca reflects localised habitat and geographical location.

Capsule Pied Flycatchers use different materials to construct their nests according to localised habitat and geographical location. Aims This study tested the hypotheses that birds would use the leaves they normally encountered within their breeding territories and that nest composition varied between geographical locations. Methods In Lancashire, Pied Flycatcher nests were collected from nestboxes built in locations dominated by different tree species and were deconstructed to determine which materials were used. Results Materials found in nests generally reflected the localised habitat around the nest rather than showing evidence of active collection from distant sources of material. Nests from Lancashire were significantly different in composition when compared with published data for nests from north Wales and central Spain. The use of moss was dominated by the use of one species in all but two nests. Conclusion Pied Flycatchers exhibit plasticity in nest construction behaviour because they were opportunistic in their choice of most nesting materials although they may be selective in their choice of moss

Report 36: Modelling ICU capacity under different epidemiological scenarios of the COVID-19 pandemic in three western European countries

The coronavirus disease 2019 (COVID-19) pandemic has placed enormous strain on healthcare systems, particularly intensive care units (ICUs), with COVID-19 patient care being a key concern of healthcare system planning for winter 2020/21. Ensuring that all patients who require intensive care, irrespective of COVID-19 status, can access it during this time is essential. This study uses an integrated model of hospital capacity planning and epidemiological projections of COVID-19 patients to estimate the spare capacity of key ICU resources under different epidemic scenarios in France, Germany and Italy across the winter period of 2020/21. In particular, we examine the effect of implementing suppression strategies of varying effectiveness, triggered by different numbers of COVID-19 patients in ICU. The use of a ‘dual-demand’ (COVID-19 and non-COVID-19) patient model and the consideration of multiple ICU resources that determine capacity (beds, doctors, nurses and ventilators) and the interdependencies between them, provides a detailed insight into potential capacity constraints this winter. Without sufficient mitigation, we estimate that COVID-19 ICU patient numbers will exceed those seen in the first peak, resulting in substantial capacity deficits, with beds being consistently found to be the most constrained resource across countries. Lockdowns triggered based on ICU capacity could lead to large improvements in spare capacity during the winter season, with pressure being most effectively alleviated when lockdown is triggered early and implemented at a higher level of suppression. In many cases, maximum deficits are reduced to lower levels which can then be managed by expanding supply-side hospital capacity, to ensure that all patients can receive treatment. The success of such interventions also depends on baseline ICU bed numbers and average non-COVID-19 patient occupancy. We find that lockdowns of longer duration reduce the total number of days in deficit, but triggering lockdown earlier when COVID-19 ICU occupancy is lower is more effective in minimising deficits. Our results highlight the dependencies between different metrics, suggesting that absolute benefits of different strategies must be weighed against the feasibility and drawbacks of different amounts of time spent in lockdown

Tail myology and flight behaviour: Differences between caracaras, falcons and forest falcons (Aves, Falconiformes)

Caracaras, falcons and forest falcons, which are representative of the three subfamilies of the family Falconidae, have different flight behaviour. Since, during flight, the tail works in coordination with the wings, the tail muscles could be indicative of the type of flight behaviour. The aim of this work was to describe in detail the little-known tail muscles of the Falconidae and to explore their possible association with this different behaviour, by using the muscle mass as an indicator. To this end, the tail muscles of 18 specimens representing the three subfamilies of Falconidae were dissected, weighed and their percentage to the body mass calculated. The possible differences in tail muscle mass between Falconinae and Polyborinae were explored with a Bayesian statistical approach. In all species, the muscles depressor caudae and levator caudae had the highest mass values (0.028%–0.329% and 0.120%–0.274%, respectively), in accordance with the key movements performed during flight, that is, the tail depression and elevation. The total muscle masses of Falconinae and those of Polyborinae were significantly different (p < 0.05). This difference can be related with the different flight behaviour of falcons and caracaras, that is, fast and erratic flight, respectively.Fil: Mosto, María Clelia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Picasso, Mariana Beatriz Julieta. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Montes, Martin Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Krone, Oliver. Leibniz Institute For Zoo And Wildlife Research.; Alemani

Composition of bird nests is a species-specific characteristic

Bird nests represent an extended phenotype of individuals expressed during reproduction and so exhibit variability in composition, structure and function. Descriptions of nests based on qualitative observations suggest that there is interspecific variation in size and composition but there are very few species in which this has been confirmed. For these species, data of the amounts of different materials indicate that nest construction behaviour is plastic and affected by a variety of factors, such as prevailing temperature, geographic location, and availability of materials. The lack of data on nest composition is hampering our understanding of how nests achieve their various functions and how different species solve the problem of building a nest that will accommodate incubation and allow successful hatching of eggs. This study deconstructed nests of four species of the Turdidae, four species of the Muscicapidae, and six species of the Fringillidae and quantified the size of the nests and their composition. These data were used to test: (1) whether nest size correlated with adult bird mass; (2) whether it was possible to distinguish between species on the basis of their nest composition; and (3) whether, within a species, it was possible to distinguish between the cup lining and the rest of the nest based on composition. Most but not all nest dimensions correlated with bird mass. Principal component analysis revealed species differences based on nest composition and discriminant analysis could distinguish cup lining from the outer nest based on material composition. Intraspecific variation in composition varied among species and in general fewer types of material were found in the cup lining than the outer nest. These data provide insight into how nests are constructed by the different species and in conjunction with studies of the mechanical, thermal and hydrological properties of a nest, will begin to reveal how and why individual species select particular combinations of materials to build a nest

Individual variation in orientation promotes a 3000-km latitudinal change in wintering grounds in a long-distance migratory raptor

Migrating juvenile birds rely on endogenous information in choosing the direction in which to fly, but such input may be overridden by social interactions with experienced individuals. We tagged seven juvenile Short-toed Eagles Circaetus gallicus with GPS transmitters in southern Italy. This trans-Saharan migrant flies mainly by soaring and is therefore not well adapted to performing long water crossings. Five of the seven tagged juveniles used the longer but apparently safer route towards the Strait of Gibraltar, and two migrated along a southerly trajectory and subsequently spent the winter in Sicily, apparently forced to do so by the 150-km-wide Sicily Channel. One of these individuals took the longer route the following autumn. These results, combined with long-term (15 years) visual field observations involving thousands of individuals, suggest that inexperienced Short-toed Eagles may learn their migratory routes from experienced adults, whereas some of them migrate south in response to an innate orientation instinct. Transport costs, inherited information and geography apparently interact, forcing some Short-toed Eagles to winter 3000 km to the north of the majority of their conspecifics.The study has been funded by the Osservatorio Faunistico of Regione Basilicata through the Parco Regionale Gallipoli Cognato – Piccole Dolomiti Lucane

Search for CP Violation in the Decay Z -> b (b bar) g

About three million hadronic decays of the Z collected by ALEPH in the years 1991-1994 are used to search for anomalous CP violation beyond the Standard Model in the decay Z -> b \bar{b} g. The study is performed by analyzing angular correlations between the two quarks and the gluon in three-jet events and by measuring the differential two-jet rate. No signal of CP violation is found. For the combinations of anomalous CP violating couplings, ${\hat{h}}_b = {\hat{h}}_{Ab}g_{Vb}-{\hat{h}}_{Vb}g_{Ab}$ and $h^{\ast}_b = \sqrt{\hat{h}_{Vb}^{2}+\hat{h}_{Ab}^{2}}$, limits of \hat{h}_b < 0.59$and$h^{\ast}_{b} < 3.02$ are given at 95\% CL.Comment: 8 pages, 1 postscript figure, uses here.sty, epsfig.st

Search for Branons at LEP

We search, in the context of extra-dimension scenarios, for the possible existence of brane fluctuations, called branons. Events with a single photon or a single Z-boson and missing energy and momentum collected with the L3 detector in e^+ e^- collisions at centre-of-mass energies sqrt{s}=189-209$ GeV are analysed. No excess over the Standard Model expectations is found and a lower limit at 95% confidence level of 103 GeV is derived for the mass of branons, for a scenario with small brane tensions. Alternatively, under the assumption of a light branon, brane tensions below 180 GeV are excluded

Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP

Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~ events. Spin correlations are favoured by data, and found to agree with the Standard Model predictions. In addition, correlations between the W-boson decay planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events. Decay-plane correlations, consistent with zero and with the Standard Model predictions, are measured

Search for Branons at LEP

We search, in the context of extra-dimension scenarios, for the possible existence of brane fluctuations, called branons. Events with a single photon or a single Z-boson and missing energy and momentum collected with the L3 detector in e^+ e^- collisions at centre-of-mass energies sqrt{s}=189-209$ GeV are analysed. No excess over the Standard Model expectations is found and a lower limit at 95% confidence level of 103 GeV is derived for the mass of branons, for a scenario with small brane tensions. Alternatively, under the assumption of a light branon, brane tensions below 180 GeV are excluded