Oystercatchers and cockles : a predatory-prey study

Oystercatchers Haematopus ostralegus and cockles Cerastoderma edule were studied with the aim of understanding the behaviour of predators and the consequences which this behaviour has on the cockle population. At Traeth Melynog, Anglesey, the cockle density declined down the shore and those at the bottom were larger, older and heavier than those at the top. This pattern was caused by the spat settling at the top of the shore combined with downshore movement of some cockles. As a consequence, both flesh content and size were correlated with prey density. The profitability (flesh eaten per minute handling time) of cockles increased with their size. According to optimal foraging theory, these larger ones should therefore have been preferred, and this proved to be so. The rate at which oystercatchers ate cockles followed a type II functional response. The plateau was not caused solely by handling time, nor were satiation or interference important. Analysis of the functional responses of other birds feeding on one prey species showed that in each case the behaviour also conformed with a type II distribution yet neither handling time nor satiation appeared responsible. To account for this, a theoretical model was developed which generates type II functional responses from optimal foraging theory. Another model was developed which predicts the aggregative numerical response for a given level of interference. Because of correlations between density, size and flesh content within the cockle population at I Traeth Melynog, this model could not be directly applied to the data. But the basic assumption of the model - that oystercatchers obeyed the ideal free distribution - could be tested. It gave a poor fit to the data. There was little measurable interference between oystercatchers feeding on cockles. The number of oystercatchers on the Ribble fluctuated in parallel with the cockle population. Much of this change appeared to be due to an influx of young birds. This suggests that young birds seek a suitable estuary whilst adults tend to return to the one found whilst young. Thus the change in oystercatcher numbers was an aggregative numerical response rather than a population numerical response. Due to correlations within the cockle population at Traeth Melynog, profitability reached a maximum value at 25-100 cockles per m2. Therefore the oystercatchers concentrated their feeding at these relatively low cockle densities. As a result, cockle mortality due to predation by oystercatchers was inversely density dependent over most of the range of densities. However, since cockle movement took place, this pattern of mortality could not be detected in the cockle population

Governance explains variation in national responses to the biodiversity crisis

SUMMARYGrowing concern about the biodiversity crisis has led to a proliferation of conservation responses, but with wide variation between countries in the levels of engagement and investment. Much of this variation is inevitably attributed to differences between nations in wealth. However, the relationship between environmentalism and wealth is complex and it is increasingly apparent that other factors are also involved. We review hypotheses that have been developed to explain variation in broad environmentalism and show that many of the factors that explain such variation in individuals, such as wealth, age and experience, also explain differences between nation states. We then assess the extent to which these factors explain variation between nation states in responses to and investment in the more specific area of biodiversity conservation. Unexpectedly, quality of governance explained substantially more variation in public and state investment in biodiversity conservation than did direct measures of wealth. The results inform assessments of where conservation investments might most profitably be directed in the future and suggest that metrics relating to governance might be of considerable use in conservation planning.</jats:p

Comparing groups versus individuals in decision making: A systematic review protocol

Background Biodiversity management requires effective decision making at various stages. However decision making in the real world is complex, driven by multiple factors and involves a range of stakeholders. Understanding the factors that influence decision making is crucial to addressing the conflicts that arise in conservation. Decisions can be made either by individuals or by groups. This precise context has been studied extensively for several decades by behavioural economists, social psychologists and intelligence analysts. The observations from these disciplines can offer useful insights for biodiversity conservation. A systematic review on group versus individual decision making is currently lacking. This systematic review would enable us to synthesize the key insights from these disciplines for a range of scenarios useful for conservation. Methods The review will document studies that have investigated differences between group and individual decision making. The focus will be on empirical studies; the comparators in this case are decisions made by individuals while the intervention is group decision making. Outcomes include level of bias in decision outcomes or group performance. The search terms will include various combinations of the words “group”, “individual” and “decision-making”. The searches will be conducted in major publication databases, google scholar and specialist databases. Articles will be screened at the title and abstract and full text level by two reviewers. After checking for internal validity, the articles will be synthesized into subsets of decision contexts in which decision making by groups and individuals have been compared. The review process, all extracted data, original studies identified in the systematic review process and inclusion and exclusion decisions will be freely available as Additional file 1 in the final review.NM is funded by the Fondation Weiner Anspach in Belgium. WJS is funded by Arcadia. LVD was supported under the Biodiversity and Ecosystem Service Sustainability (BESS) Programme, grant code NE/K015419/1. GES is funded by The Nature Conservancy.This is the final version of the article. It first appeared from BioMed Central via http://dx.doi.org/10.1186/s13750-016-0066-

The role of churches in maintaining bird diversity: A case study from southern Poland

© 2018 Elsevier Ltd With the human population increasing there have been losses in biodiversity. A common feature of mankind is religious beliefs with various associated positive and negative consequences for biodiversity. Religion also has associated religious sites, many of which have a long history. The role of churches in benefitting biodiversity has not received attention. To examine the impact of churches we measured the taxonomic, phylogenetic and functional diversity of birds around Christian churches and compared this with matched farmsteads. We surveyed 101 churches and equal number of farmsteads in villages of southern Poland. We measured structural and compositional characteristics (e.g. number of trees, shrubs, number of buildings and height) at both churches and farmsteads. General additive models, ordination and rarefactions methods were used in data analysis. Species richness, abundance and phylogenetic diversity were each higher at churches than at farmsteads. The species composition differed between building types but functional diversity was similar at both types of buildings. Bird species richness and abundance were correlated with the church's age. Previous studies showed village farmsteads supported high species diversity, thus our current findings that churches are richer show they may increase bird diversity in studied villages. We suggest that the green surroundings and tall towers create strong environmental gradient that enhances species richness, functional and phylogenetic diversity. There are over ten thousand churches in Poland, and similar places of worship are present in many religions, thus this habitat may be important for sustaining local taxonomic, functional and phylogenetic biodiversity in different global areas

Where on Earth Are the Best-50 Time Servers?

© 2019, Springer Nature Switzerland AG. We present a list of the Best-50 public IPv4 time servers by mining a high-resolution dataset of Stratum-1 servers for Availability, Stratum Constancy, Leap Performance, and Clock Error, broken down by continent. We find that a server with ideal leap performance, high availability, and low stratum variation is often clock error-free, but this is no guarantee. We discuss the relevance and lifetime of our findings, the scalability of our approach, and implications for load balancing and server ranking

Simple study designs in ecology produce inaccurate estimates of biodiversity responses

Monitoring the impacts of anthropogenic threats and interventions to mitigate these threats is key to understanding how to best conserve biodiversity. Ecologists use many different study designs to monitor such impacts. Simpler designs lacking controls (e.g. Before-After (BA) and After) or pre-impact data (e.g. Control-Impact (CI)) are considered to be less robust than more complex designs (e.g. Before-After Control-Impact (BACI) or Randomised Controlled Trials (RCTs)). However, we lack quantitative estimates of how much less accurate simpler study designs are in ecology. Understanding this could help prioritise research and weight studies by their design’s accuracy in meta-analysis and evidence assessment. 2. We compared how accurately five study designs estimated the true effect of a simulated environmental impact that caused a step-change response in a population’s density. We derived empirical estimates of several simulation parameters from 47 ecological datasets to ensure our simulations were realistic. We measured design performance by determining the percentage of simulations where: (i) the true effect fell within the 95% Confidence Intervals of effect size estimates, and (ii) each design correctly estimated the true effect’s direction and magnitude. We also considered how sample size affected their performance. 3. We demonstrated that BACI designs performed: 1.3-1.8 times better than RCTs; 2.9-4.2 times vs BA; 3.2-4.6 times vs CI; and 7.1-10.1 times vs After designs (depending on sample size), when correctly estimating true effect’s direction and magnitude to within ±30%. Although BACI designs suffered from low power at small sample sizes, they outperformed other designs for almost all performance measures. Increasing sample size improved BACI design accuracy but only increased the precision of simpler designs around biased estimates. 4. Synthesis and applications. We suggest that more investment in more robust designs is needed in ecology since inferences from simpler designs, even with large sample sizes may be misleading. Facilitating this requires longer-term funding and stronger research-practice partnerships. We also propose ‘accuracy weights’ and demonstrate how they can weight studies in three recent meta-analyses by accounting for study design and sample size. We hope these help decision-makers and meta-analysts better account for study design when assessing evidence

Spatial Gaps in Global Biodiversity Information and the Role of Citizen Science

Due to a range of constraints, the availability of biodiversity-related information varies considerably over space, time, taxa and types of data, thus causing gaps in knowledge. Despite growing awareness of this issue among scientists, it is still poorly known how, and whether, scientific efforts have contributed towards overcoming these information gaps. Focusing on spatial gaps in global biodiversity data, we show that accumulation rates of non-bird species occurrence records stored in the Global Biodiversity Information Facility have not improved, and have even potentially declined, over the past three decades in data-poor, often biodiversity-rich, regions. Meanwhile, one citizen science project, eBird, has been making a considerable contribution to the collection and sharing of bird records, even in data-poorest countries and is accelerating the accumulation of bird records globally. We discuss the potentials and limitations of citizen science projects for tackling gaps in biodiversity information, particularly from the perspective of biodiversity conservation.T.A. was supported by the European Commission’s Marie Curie International Incoming Fellowship Programme (PIIF-GA-2011-303221) and the Isaac Newton Trust and W.J.S. by the Arcadia Fund. Thanks to Timothy Beardsley, René van der Wal and two anonymous reviewers for their comments on an earlier draft and M. Amano for all the support.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Oxford University Press