Changing numbers of three gull species in the British Isles

Between-population variation of changes in numbers can provide insights into factors influencing variation in demography and how population size or density is regulated. Here, we describe spatio-temporal patterns of population change of Herring Gull (Larus argentatus), Lesser Black-backed Gull (L. fuscus) and Great Black-backed Gull (L. marinus) in the British Isles from national censuses and survey data. The aim of this study was to test for density-dependence and spatial variation in population trends as two possible, but not mutually exclusive, explanations of population changes with important implications for the understanding of these changes. Between 1969 and 2013 the three species showed different population trends with Herring Gulls showing a strong decline, Great Black-backed Gulls a less pronounced decline and Lesser Black-backed Gulls an increase until 2000 but then a decline since. Population changes also varied between different regions of the British Isles, with the Atlantic coast showing declines and the North Sea coast increases in all three species. Population changes were density-dependent in the Herring Gull, and Lesser Black-backed Gulls showed faster population increases at lower Herring Gull densities. Contrasting numbers of gulls nest in coastal habitats or on roofs (mainly in urban habitats). Herring Gulls seem to seek refuge in urban environments, whereas Lesser Black-backed Gulls expand their range into the urban environment. The large declines in hitherto abundant species create a dilemma for conservation bodies in prioritizing conservation policies. The spatial variation in population changes and the differences between species suggest that there is no single cause for the observed changes, thus requiring region-specific conservation management strategies

The value relevance of disclosures of liabilities of equity-accounted investees: UK evidence

This study examines the value relevance of mandated disclosures by UK firms of the investor-firm share of liabilities of equity-accounted associate and joint venture investees. It does so for the six years following the introduction of FRS 9: Associates and Joint Ventures, which forced a substantial increase in such disclosures by UK firms. Since the increased disclosure requirements were partly motivated by concern that single-line equity accounting concealed the level of group gearing, and in light of previous US results, it is predicted that the mandated investee-liability disclosures have a negative coefficient in a value-relevance regression. The study also examines whether value-relevance regression coefficients on investee-liability disclosures are more negative for joint ventures than for associates and whether they are more negative in the presence of investor-firm guarantees of investee-firm obligations than in the absence of such guarantees. The study reports that the coefficient on all investee-liability disclosures taken together has the predicted negative sign, and is significantly different from zero. It finds little evidence that the negative valuation impact of liability disclosures is stronger for joint venture investees overall than for associate investees overall, or stronger for guarantee cases overall than for non-guarantee cases overall. There is, however, some evidence that the impact for joint venture guarantee cases is stronger than that for joint venture non-guarantee cases and stronger than that for associate guarantee cases

Conservative accounting and linear information valuation models

Prior research using the residual income valuation model and linear information models has generally found that estimates of firm value are negatively biased. We argue that this could result from the way in which accounting conservatism effects are reflected in such models. We build on the conservative accounting model of Feltham and Ohlson (1995) and the Dechow, Hutton and Sloan (1999) (DHS) methodology to propose a valuation model that includes a conservatism-correction term, based on the properties of past realizations of residual income and other information. Other information is measured using analyst-forecast-based predictions of residual income. We use data comparable to the DHS sample to compare the bias and inaccuracy of value estimates from our model and from models similar to those used by DHS and Myers (1999). Valuation biases are substantially less negative for our model, but valuation inaccuracy is not markedly reduced

Increased use of intertidal resources benefits breeding success in a generalist gull species

Determining how resource use impacts on a species’ demography is important, especially in habitats which are being altered by anthropogenic land-use change. If changes result in species consuming resources of reduced quality their demographic traits may be adversely affected. Generalist species are useful when investigating changes in resource availability as they can switch to alternatives if their preferred food becomes unavailable. For species that can forage on marine and terrestrial resources, it is often not known whether a switch from marine to terrestrial resources will have negative consequences. The herring gull, Larus argentatus, is one widespread generalist that opportunistically forages within marine and terrestrial habitats that are increasingly altered by humans. We determined marine and terrestrial resource use of gulls from eight colonies over two years across south-west Scotland and Northern Ireland using pellets and stable isotope analysis of chick feathers, which gave comparable results. Herring gulls in the study region used very little marine offshore resources but birds from colonies located in areas with sheltered coastlines, which provide abundant and diverse marine food from the intertidal zone, foraged more on marine intertidal resources. In contrast, colonies closer to built-up areas used more terrestrial resources. Herring gulls raised larger broods in colonies where they consumed a higher proportion of marine resource. Therefore, where generalist species, such as gulls, switch to an alternative resources that is available to them within their foraging range this may come at a cost of lower breeding success

Fostering resilience-oriented thinking in engineering practice

Round tables discussing the resilience of critical infrastructure systems held in the UK, the USA and New Zealand have provided insight into how organisations are changing the basis of planning and investment decisions to enhance resilience. The events convened stakeholders to explore how resilience is embraced in their sectors and to identify how to advance practice. The overarching premise was to convene a diverse group who would not typically have an opportunity to engage with each other, to share their perspectives on putting resilience thinking into practice. The round tables identified that early-adopting organisations are implementing approaches to decision making that embrace resilience thinking, but such approaches are not yet embedded in common practice across organisations that are responsible for planning and managing critical infrastructure. The findings emphasise that multi-agency coordination and collaboration is required to advance resilience thinking in professional practice and to move beyond traditional risk-based paradigms. Governance and policy interventions will help encourage cross-sector information sharing and enforce responsibility and transparency surrounding exposure to potential shocks and stresses. It is recommended that such interventions could expand on principles and practice in existing emergency-management efforts, on the basis that such efforts are founded on coordinating various groups. </jats:p

A cross-sectional study of retired Great British Olympians (Berlin 1936 - Sochi 2014):Olympic career injuries, joint health in later life, and reasons for retirement from Olympic sport

The relationship between Olympic career sport injury and the long-term musculoskeletal health of the elite athlete remains unclear. This study describes the lifetime prevalence of medical attention injuries that occurred during training and/or competition as part of the athlete’s Olympic career, reasons for retirement from Olympic sport, and the point prevalence of pain and osteoarthritis (OA) among retired Great Britain’s (GB) Olympians