Representing the acquisition and use of energy by individuals in agent-based models of animal populations

Summary 1. Agent-based models (ABMs) are widely used to predict how populations respond to changing environments. As the availability of food varies in space and time, individuals should have their own energy budgets, but there is no consensus as to how these should be modelled. Here, we use knowledge of physiological ecology to identify major issues confronting the modeller and to make recommendations about how energy budgets for use in ABMs should be constructed. 2. Our proposal is that modelled animals forage as necessary to supply their energy needs for maintenance, growth and reproduction. If there is sufficient energy intake, an animal allocates the energy obtained in the order: maintenance, growth, reproduction, energy storage, until its energy stores reach an optimal level. If there is a shortfall, the priorities for maintenance and growth/reproduction remain the same until reserves fall to a critical threshold below which all are allocated to maintenance. Rates of ingestion and allocation depend on body mass and temperature. We make suggestions for how each of these processes should be modelled mathematically. 3. Mortality rates vary with body mass and temperature according to known relationships, and these can be used to obtain estimates of background mortality rate. 4. If parameter values cannot be obtained directly, then values may provisionally be obtained by parameter borrowing, pattern-oriented modelling, artificial evolution or from allometric equations. 5. The development of ABMs incorporating individual energy budgets is essential for realistic modelling of populations affected by food availability. Such ABMs are already being used to guide conservation planning of nature reserves and shell fisheries, to assess environmental impacts of building proposals including wind farms and highways and to assess the effects on nontarget organisms of chemicals for the control of agricultural pests. Keywords: bioenergetics; energy budget; individual-based models; population dynamics.

Animal disease and the limits of local knowledge: dealing with ticks and tick-borne diseases in South Africa

Some proponents of local knowledge, such as Sillitoe (2010), have expressed second thoughts about its capacity to effect development on the ‘revolutionary’ scale once predicted. Our argument in this article follows a similar route. Recent research into the management of livestock in South Africa makes clear that rural African livestock farmers experience uncertainty in relation to the control of stock diseases. State provision of veterinary services has been significantly reduced over the past decade. Both white and African livestock owners are to a greater extent left to their own devices. In some areas of animal disease management, African livestock owners have recourse to tried-and-tested local remedies, which are largely plant-based. But especially in the critical sphere of tick control, efficacious treatments are less evident, and livestock owners struggle to find adequate solutions to high tickloads. This is particularly important in South Africa in the early twenty-first century because land reform and the freedom to purchase land in the post-apartheid context affords African stockowners opportunities to expand livestock holdings. Our research suggests that the limits of local knowledge in dealing with ticks is one of the central problems faced by African livestock owners. We judge this not only in relation to efficacy but also the perceptions of livestock owners themselves. While confidence and practice varies, and there is increasing resort of chemical acaricides we were struck by the uncertainty of livestock owners over the best strategies.

Proctolaelaps euserratus, an ecologically unusual melicharid mite (Acari, Mesostigmata) associated with animal and human decomposition.

Proctolaelaps euserratus Karg, 1994 (Acari, Mesostigmata, Melicharidae), exclusivelly known from the Galápagos Islands till now, is newly reported from decaying matter of animal and human decomposition in various countries of Europe (Slovakia, Spain, United Kingdom). In consequence of high levels of necrophilia, the species is considered to be ecologically unusual among the other melicharids, which are primary associated with other than necrophilic habitats, such as galleries of subcorticolous beetles, bumble bee nests, flowers, etc. Proctolaelaps euserratus is reviewed, morphologically re-described (with first diagnostic characters for males), and considered as a new potential marker for later stages of decomposition, namely butyric fermentation and dry decomposition as classified in modern concepts of forensic acarology.

Combined effects of global change pressures on animal-mediated pollination

Pollination is an essential process in the sexual reproduction of seed plants and a key ecosystem service to human welfare. Animal pollinators decline as a consequence of five major global change pressures: climate change, landscape alteration, agricultural intensification, non-native species, and spread of pathogens. These pressures, which differ in their biotic or abiotic nature and their spatiotemporal scales, can interact in nonadditive ways (synergistically or antagonistically), but are rarely considered together in studies of pollinator and/or pollination decline. Management actions aimed at buffering the impacts of a particular pressure could thereby prove ineffective if another pressure is present. Here, we focus on empirical evidence of the combined effects of global change pressures on pollination, highlighting gaps in current knowledge and future research needs.

Inferring animal husbandry strategies in coastal zones through stable isotope analysis: new evidence from the Flemish coastal plain (Belgium, 1st-15th century AD)

In a proof-of-concept study, Britton et al. (2008) demonstrated that the isotopic composition of halophytic plants can be traced in the skeletal tissues of their animal consumers. Here we apply the method to domestic herbivore remains (n = 303) from nine archaeological sites in or near the Flemish coastal plain (Belgium), where, prior to embankments, salt-marshes offered extensive pasture grounds for domestic herbivores. The sites span a period of ∼1500 years (Roman to late medieval period), during which the coastal landscape was progressively transformed from little managed wetlands to a fully embanked polder area. The bulk collagen data show variations between sites and over time, which are consistent with this historical framework and are interpreted as reflecting environmental change and differences in animal management in the coastal plain throughout the late Holocene. The study demonstrates the immense value of faunal stable isotope analysis for characterising coastal husbandry strategies beyond the means of traditional zooarchaeological techniques.

Tactical ethics: how the discourses of fairtrade and black economic empowerment change and interact in wine networks from South Africa to the UK.

This paper explores the spaces and power relations of ethical foodscapes. Ethics can offer a commodity a valuable unique selling point in a competitive marketplace but managing the changeable and multiple motivations for stakeholder participation throughout the commodity chain in order to utilise this opportunity is a complex negotiation. Through exploring the spaces and relations within three South African– UK ethical wine networks, the discursive tactics used to sustain these are uncovered. The discourses of Fairtrade, Black Economic Empowerment and organics are highly adaptive, interacting with each other in such a way as to always be contextually appealing. This ‘tactical mutability’ is combined with ‘scales of knowing’, which, this paper argues, are essential for network durability. ‘Scales of knowing’ refers to the recognition by stakeholders of the potential for different articulations of a discourse within the network, which combines with ‘tactical mutability’ to allow for a scalar, contextual and ’knowing’ (im)mutability to ensure the discourse’s continued appeal. However, even when one discourse is the ‘lead’ it always folds within it linkages to other ethical discourses at work, suggesting that ethical practice is mutually supportive discursively. This means that at the producer end ethical interactions may offer more capacity to enact genuine transformation than the solo operations of a discourse.

Educating integrated catalysts: transforming business schools toward ethics and sustainability

Joining the sharpening critique of conventional University-based business school education, we argue that educating integrated catalysts is necessary to meet current sustainability challenges. The key feature of moving toward the integration required at the individual level is focusing on developing students' capacity for moral and cognitive maturity. Practically, this makes the practice of genuine dialogue focal as core interpersonal method for educating management students. In supporting such education, business schools must however first transform themselves. Acting as transformative social enterprises, they can demonstrate being a part in critically questioning and improving the impact and relevance of management on the flourishing of wider society and the practice of an ethically oriented economy. We offer practical suggestions and implications for future business education reform.

Market research and the ethics of big data

The term 'big data' has recently emerged to describe a range of technological and commercial trends enabling the storage and analysis of huge amounts of customer data, such as that generated by social networks and mobile devices. Much of the commercial promise of big data is in the ability to generate valuable insights from collecting new types and volumes of data in ways that were not previously economically viable. At the same time a number of questions have been raised about the implications for individual privacy. This paper explores key perspectives underlying the emergence of big data, and considers both the opportunities and ethical challenges raised for market research.