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1. Timing of breeding, an important driver of fitness in many populations, is widely studied in the context of global change, yet despite considerable efforts to identify environmental drivers of seabird nesting phenology, for most populations we lack evidence of strong drivers. Here we adopt an alternative approach, examining the degree to which different populations positively covary in their annual phenology to infer whether phenological responses to environmental drivers are likely to be (i) shared across species at a range of spatial scales, (ii) shared across populations of a species, or (iii) idiosyncratic to populations. 2. We combined 51 long-term datasets on breeding phenology spanning 50 years from nine seabird species across 29 North Atlantic sites and examined the extent to which different populations share early versus late breeding seasons depending on a hierarchy of spatial scales comprising breeding site, small-scale region, large-scale region and the whole North Atlantic. 3. In about a third of cases we found laying dates of populations of different species sharing the same breeding site or small-scale breeding region were positively correlated, which is consistent with the hypothesis that they share phenological responses to the same environmental conditions. In comparison we found no evidence for positive phenological covariation among populations across species aggregated at larger spatial scales. 4. In general we found little evidence for positive phenological covariation between populations of a single species, and in many instances the inter-year variation specific to a population was substantial, consistent with each population responding idiosyncratically to local environmental conditions. Black-legged kittiwake (Rissa tridactyla) was the exception, with populations exhibiting positive covariation in laying dates that decayed with the distance between breeding sites, suggesting that populations may be responding to a similar driver. 5. Our

This article-third in a series of three-uses theoretical frameworks described in Part 1, and empirical markers reported in Part 2, to present evidence on how power dynamics shifted during the early years of a major English community empowerment initiative. We demonstrate how the capabilities disadvantaged communities require to exercise collective control over decisions/actions impacting on their lives and health (conceptualized as emancipatory power) and the exercise of power over these communities (conceptualized as limiting power) were shaped by the characteristics of participatory spaces created by and/or associated with this initiative. Two main types of participatory spaces were identified: governance and sense-making. Though all forms of emancipatory power emerged in all spaces, some were more evident in particular spaces. In governance spaces, the development and enactment of 'power to' emerged as residents made formal decisions on action, allocated resources and managed accountability. Capabilities for alliance building-power with-were more likely to emerge in these spaces, as was residents' resistance to the exercise of institutional power over them. In contrast, in sense-making spaces residents met informally and 'made sense' of local issues and their ability to influence these. These processes led to the development of power within capabilities and power to resist stigmatizing forms of productive power. The findings highlight the importance of designing community initiatives that: nurture diverse participatory spaces; attend to connectivity between spaces; and identify and act on existing power dynamics undermining capabilities for collective control in disadvantaged communities.

In the health field, there is great interest in the role empowerment might play in reducing social inequalities in health. Empowerment is understood here as the processes of developing capabilities that individuals and/or communities need to exercise control over decisions and actions impacting on their lives and health. There is a fundamental problem, however, in identifying and measuring capabilities for collective control that emerge at the level of the collective, with much of the existing literature focusing on individual measures even where community-level processes are concerned. Collective measures need to capture the dynamics of interactions within and between groups, not simply aggregate individual-level measures. This article, Part 2 in a three-part series, takes up the challenge of identifying qualitative markers of capabilities for collective control. We applied the emancipatory power framework (EPF) reported in Part 1 of the series, to qualitative data generated during a longitudinal evaluation of a major English area-based empowerment initiative, the Big Local (BL). We identified empirical 'markers' of shifts towards greater collective control pertaining to each of the 'power' dimensions in the EPF-'power within', 'power with' and 'power to'-and markers of communities exercising 'power over' other institutions/community members. These markers can usefully be applied in the evaluation planning and evaluation of empowerment initiatives. Part 3 in the series uses these markers and a second analytical framework developed during our evaluation of BL to explore how power dynamics unfold in participatory spaces in BL neighbourhoods.

This article-third in a series of three-uses theoretical frameworks described in Part 1, and empirical markers reported in Part 2, to present evidence on how power dynamics shifted during the early years of a major English community empowerment initiative. We demonstrate how the capabilities disadvantaged communities require to exercise collective control over decisions/actions impacting on their lives and health (conceptualized as emancipatory power) and the exercise of power over these communities (conceptualized as limiting power) were shaped by the characteristics of participatory spaces created by and/or associated with this initiative. Two main types of participatory spaces were identified: governance and sense-making. Though all forms of emancipatory power emerged in all spaces, some were more evident in particular spaces. In governance spaces, the development and enactment of 'power to' emerged as residents made formal decisions on action, allocated resources and managed accountability. Capabilities for alliance building-power with-were more likely to emerge in these spaces, as was residents' resistance to the exercise of institutional power over them. In contrast, in sense-making spaces residents met informally and 'made sense' of local issues and their ability to influence these. These processes led to the development of power within capabilities and power to resist stigmatizing forms of productive power. The findings highlight the importance of designing community initiatives that: nurture diverse participatory spaces; attend to connectivity between spaces; and identify and act on existing power dynamics undermining capabilities for collective control in disadvantaged communities.

In the health field, there is great interest in the role empowerment might play in reducing social inequalities in health. Empowerment is understood here as the processes of developing capabilities that individuals and/or communities need to exercise control over decisions and actions impacting on their lives and health. There is a fundamental problem, however, in identifying and measuring capabilities for collective control that emerge at the level of the collective, with much of the existing literature focusing on individual measures even where community-level processes are concerned. Collective measures need to capture the dynamics of interactions within and between groups, not simply aggregate individual-level measures. This article, Part 2 in a three-part series, takes up the challenge of identifying qualitative markers of capabilities for collective control. We applied the emancipatory power framework (EPF) reported in Part 1 of the series, to qualitative data generated during a longitudinal evaluation of a major English area-based empowerment initiative, the Big Local (BL). We identified empirical 'markers' of shifts towards greater collective control pertaining to each of the 'power' dimensions in the EPF-'power within', 'power with' and 'power to'-and markers of communities exercising 'power over' other institutions/community members. These markers can usefully be applied in the evaluation planning and evaluation of empowerment initiatives. Part 3 in the series uses these markers and a second analytical framework developed during our evaluation of BL to explore how power dynamics unfold in participatory spaces in BL neighbourhoods.

Reproductive timing in many taxa plays a key role in determining breeding productivity(1), and is often sensitive to climatic conditions(2). Current climate change may alter the timing of breeding at different rates across trophic levels, potentially resulting in temporal mismatch between the resource requirements of predators and their prey(3). This is of particular concern for higher-trophic-level organisms, whose longer generation times confer a lower rate of evolutionary rescue than primary producers or consumers(4). However, the disconnection between studies of ecological change in marine systems makes it difficult to detect general changes in the timing of reproduction(5). Here, we use a comprehensive meta-analysis of 209 phenological time series from 145 breeding populations to show that, on average, seabird populations worldwide have not adjusted their breeding seasons over time (-0.020 days yr(-1)) or in response to sea surface temperature (SST) (-0.272 days degrees C-1) between 1952 and 2015. However, marked between-year variation in timing observed in resident species and some Pelecaniformes and Suliformes (cormorants, gannets and boobies) may imply that timing, in some cases, is affected by unmeasured environmental conditions. This limited temperature-mediated plasticity of reproductive timing in seabirds potentially makes these top predators highly vulnerable to future mismatch with lower-trophic-level resources(2).

Technological advances in recent years have seen an explosion of tracking and stable isotope studies of seabirds, often involving repeated measures from the same individuals. This wealth of new information has allowed the examination of the extensive variation among and within individuals in foraging and migration strategies (movements, habitat use, feeding behaviour, trophic status, etc.) in unprecedented detail. Variation is underpinned by key life-history or state variables such as sex, age, breeding stage and residual differences among individuals (termed ‘individual specialization’). This variation has major implications for our understanding of seabird ecology, because it affects the use of resources, level of intra-specific competition and niche partitioning. In addition, it determines the responses of individuals and populations to the environment and the susceptibility to major anthropogenic threats. Here we review the effects of season (breeding vs. nonbreeding periods), breeding stage, breeding status, age, sex and individual specialization on foraging and migration strategies, as well as the consequences for population dynamics and conservation.

It is now widely accepted that context matters in evaluations of the health inequalities impact of community-based social initiatives. Systems thinking offers a lens for uncovering the dynamic relationship between such initiatives and their social contexts. However, there are very few examples that show how a systems approach can be applied in practice and what kinds of evidence are produced when this happens. In this paper, we use data from ethnographic fieldwork embedded within a multi-site mixed method evaluation to demonstrate how a systems approach can be applied in practice to evaluate the early stages of an area-based empowerment initiative – Big Local (funded by the Big Lottery Fund and delivered by Local Trust). Taking place in 150 different local areas in England and underpinned by an ethos of resident-led collective action, Big Local offers an illustration of the applicability of a systems approach to better understand the change processes that emerge as social initiatives embed and co-evolve within a series of local contexts. Findings reveal which parts of the social system are likely to be changed, by what mechanisms, and with what implications. They also raise some salient considerations for knowledge generation and methods development in public health evaluation, particularly for the evaluation of social initiatives where change does not necessarily happen in linear or predictable ways. We suggest future evaluations of such initiatives require the use of more flexible designs, encompassing qualitative approaches capable of capturing the complexity of relational systems processes, alongside more traditional quantitative methods.

It is now widely accepted that context matters in evaluations of the health inequalities impact of community-based social initiatives. Systems thinking offers a lens for uncovering the dynamic relationship between such initiatives and their social contexts. However, there are very few examples that show how a systems approach can be applied in practice and what kinds of evidence are produced when this happens. In this paper, we use data from ethnographic fieldwork embedded within a multi-site mixed method evaluation to demonstrate how a systems approach can be applied in practice to evaluate the early stages of an area-based empowerment initiative – Big Local (funded by the Big Lottery Fund and delivered by Local Trust). Taking place in 150 different local areas in England and underpinned by an ethos of resident-led collective action, Big Local offers an illustration of the applicability of a systems approach to better understand the change processes that emerge as social initiatives embed and co-evolve within a series of local contexts. Findings reveal which parts of the social system are likely to be changed, by what mechanisms, and with what implications. They also raise some salient considerations for knowledge generation and methods development in public health evaluation, particularly for the evaluation of social initiatives where change does not necessarily happen in linear or predictable ways. We suggest future evaluations of such initiatives require the use of more flexible designs, encompassing qualitative approaches capable of capturing the complexity of relational systems processes, alongside more traditional quantitative methods.

Parasitic infection has a direct physiological cost to hosts but may also alter how hosts interact with other individuals in their environment. Such indirect effects may alter both host fitness and the fitness of other individuals in the host's social network, yet the relative impact of direct and indirect effects of infection are rarely quantified. During reproduction, a host's social environment includes family members who may be in conflict over resource allocation. In such situations, infection may alter how resources are allocated, thereby redistributing the costs of parasitism between individuals. Here, we experimentally reduce parasite burdens of parent and/or nestling European shags (Phalacrocorax aristotelis) infected with Contracaecum nematodes in a factorial design, then simultaneously measure the impact of an individual's infection on all family members. We found no direct effect of infection on parent or offspring traits but indirect effects were detected in all group members, with both immediate effects (mass change and survival) and longer-term effects (timing of parents’ subsequent breeding). Our results show that parasite infection can have a major impact on individuals other than the host, suggesting that the effect of parasites on population processes may be greater than previously thought.

Background Evaluation of community empowerment initiatives for their effects on health inequalities presents a paradox to researchers. By definition, such initiatives aim to empower people to influence decisions that affect their lives. However, once empowered, people might not necessarily take the decisions that the originators of the intervention desired. The inability to control the implementation of an intervention goes against all the basic principles of intervention trials. We studied a community empowerment initiative, using a systems approach, to see whether any ensuing diversity of implementation could be used as an advantage rather than be a problem for an evaluation design. Methods We conducted qualitative in-depth case studies in ten intervention neighbourhoods in England, including a total of 150 resident interviews and ethnographic observation, interviews with the national organisations involved, and a review of plans from 30 intervention sites. Data were coded in NVivo (version 10) in a pre-defined thematic framework. Narrative memos were developed and compared and contrasted across sites. Findings The initiative's overarching objective was to increase confidence and skills to enable residents to identify priorities and take action in their neighbourhoods. Our fieldwork found that the core objective was pursued in different ways: building connections across people living or working in the neighbourhood, promoting social participation, improving or so-called lifting an area's external reputation, achieving material improvements (eg, parks), and addressing debt or unemployment. Diversity in starting points of local area systems also contributed to divergence in the aspirations that residents identified, the actions being taken to achieve them, and the change in processes that ensued. Interpretation Understanding interventions as events in systems offers an approach that shifts the focus of assessment from what works to what happens when an intervention

Parasites play key ecological and evolutionary roles through the costs they impose on their host. In wild populations, the effect of parasitism is likely to vary considerably with environmental conditions, which may affect the availability of resources to hosts for defense. However, the interaction between parasitism and prevailing conditions is rarely quantified. In addition to environmental variation acting on hosts, individuals are likely to vary in their response to parasitism, and the combined effect of both may increase heterogeneity in host responses. Offspring hierarchies, established by parents in response to uncertain rearing conditions, may be an important source of variation between individuals. Here, we use experimental antiparasite treatment across 5 years of variable conditions to test how annual population productivity (a proxy for environmental conditions) and parasitism interact to affect growth and survival of different brood members in juvenile European shags (Phalacrocorax aristotelis). In control broods, last-hatched chicks had more plastic growth rates, growing faster in more productive years. Older siblings grew at a similar rate in all years. Treatment removed the effect of environment on last-hatched chicks, such that all siblings in treated broods grew at a similar rate across environmental conditions. There were no differences in nematode burden between years or siblings, suggesting that variation in responses arose from intrinsic differences between chicks. Whole-brood growth rate was not affected by treatment, indicating that within-brood differences were driven by a change in resource allocation between siblings rather than a change in overall parental provisioning. We show that gastrointestinal parasites can be a key component of offspring's developmental environment. Our results also demonstrate the value of considering prevailing conditions for our understanding of parasite effects on host life-history traits. Establishing how envir

Carry-over effects have major implications for individual fitness and population and evolutionary dynamics. The strength of these effects is dependent on an individual's intrinsic performance and the environmental conditions it experiences. However, understanding the relative importance of environmental and intrinsic effects underpinning seasonal interactions has proved extremely challenging, since they co-vary. A powerful approach is longitudinal measurement of individuals across a range of conditions whereby each animal is effectively acting as its own control. We related time spent foraging during the nonbreeding period to subsequent breeding performance in European shags Phalacrocorax aristotelis. By following individuals for up to six years, we could test simultaneously for extrinsic and intrinsic effects using random regression modelling. We detected significant annual and among-individual variation in daily foraging time during the late winter, and clear variation among individuals in the quadratic relationship between foraging time and date. Shorter foraging times were associated with earlier and more successful breeding, driven by differences among years and individuals, with no evidence of individual variation in the slope of these relationships. That both environmental and intrinsic variation shape carry-over effects has important implications for population responses to environmental change.

The processes driving age-related variation in demographic rates are central to understanding population and evolutionary ecology. An increasing number of studies in wild vertebrates find evidence for improvements in reproductive performance traits in early adulthood, followed by senescent declines in later life. However, life history theory predicts that reproductive investment should increase with age as future survival prospects diminish, and that raised reproductive investment may have associated survival costs. These non-mutually exclusive processes both predict an increase in breeding performance at the terminal breeding attempt. Here, we use a 30-year study of wandering albatrosses (Diomedea exulans) to disentangle the processes underpinning age-related variation in reproduction. Whilst highlighting the importance of breeding experience, we reveal senescent declines in performance are followed by a striking increase in breeding success and a key parental investment trait at the final breeding attempt.