Open Air Laboratories (OPAL): a community-driven research programme

OPAL is an English national programme that takes scientists into the community to investigate environmental issues. Biological monitoring plays a pivotal role covering topics of: i) soil and earthworms; ii) air, lichens and tar spot on sycamore; iii) water and aquatic invertebrates; iv) biodiversity and hedgerows; v) climate, clouds and thermal comfort. Each survey has been developed by an inter-disciplinary team and tested by voluntary, statutory and community sectors. Data are submitted via the web and instantly mapped. Preliminary results are presented, together with a discussion on data quality and uncertainty. Communities also investigate local pollution issues, ranging from nitrogen deposition on heathlands to traffic emissions on roadside vegetation. Over 200,000 people have participated so far, including over 1000 schools and 1000 voluntary groups. Benefits include a substantial, growing database on biodiversity and habitat condition, much from previously unsampled sites particularly in urban areas, and a more engaged public.

Impact of biodiversity-climate futures on primary production and metabolism in a model benthic estuarine system

Background

Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production) to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB) are vital for autochthonous carbon fixation. The level of in situ production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO₂ concentrations (370, 600, and 1000 ppmv), temperature (6°C, 12°C, and 18°C) and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (Hydrobia ulvae, Corophium volutator and Hediste diversicolor) in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness.

Results

The effects of elevated CO₂ concentration, temperature and invertebrate diversity were not additive, rather they interacted to determine MPB biomass, and overall this effect was negative. Diversity effects were underpinned by strong species composition effects, illustrating the importance of individual species identity.

Conclusions

Overall, our findings suggest that in natural systems, the complex interactions between changing environmental conditions and any associated changes in invertebrate assemblage structure are likely to reduce MPB biomass. Furthermore, these effects would be sufficient to affect the net metabolic balance of the coastal ecosystem, with important implications for system ecology and sustainable exploitation.

Use of proximity loggers and network analysis to quantify social interactions in free-ranging wild rabbit populations

Context Social structure of group-living animals has important implications for processes such as gene flow, information transfer, resource utilisation, and disease spread. However, due to the difficulties associated with measuring relationships among wild animals and deriving meaningful estimates of social structure from these interactions, quantifying sociality of evasive species can be challenging. Aims Our aim was to quantify the pattern of social interactions among free-ranging European wild rabbits (Oryctolagus cuniculus) in a temperate region of Australia. Methods We used proximity logging devices to collect data on the dyadic interactions among two populations of rabbits. We then applied recently developed social structure and network analytical techniques to infer estimates of sociality and contact networks from recorded interactions. Key results We found large heterogeneities in the strength of association indices and network centrality measures within but not between populations. Network analytical techniques revealed clustering of rabbits into distinct social groups. Conclusions Most associations within social groups were strong and highly stable over time whereas interactions between groups were rare and transient, indicating low levels of inter-group mixing. Despite the apparent differences in habitat quality between sites, the network characteristics were extremely similar between the two populations. Implications Our results highlight the importance of heterogeneities in individual behaviour in determining the dynamics of directly transmitted diseases at the population level.

Marine biodiversity-ecosystem functions under uncertain environmental futures

Anthropogenic activity is currently leading to dramatic transformations of ecosystems and losses of biodiversity. The recognition that these ecosystems provide services that are essential for human well-being has led to a major interest in the forms of the biodiversity-ecosystem functioning relationship. However, there is a lack of studies examining the impact of climate change on these relationships and it remains unclear how multiple climatic drivers may affect levels of ecosystem functioning. Here, we examine the roles of two important climate change variables, temperature and concentration of atmospheric carbon dioxide, on the relationship between invertebrate species richness and nutrient release in a model benthic estuarine system. We found a positive relationship between invertebrate species richness and the levels of release of NH(4)-N into the water column, but no effect of species richness on the release of PO(4)-P. Higher temperatures and greater concentrations of atmospheric carbon dioxide had a negative impact on nutrient release. Importantly, we found significant interactions between the climate variables, indicating that reliably predicting the effects of future climate change will not be straightforward as multiple drivers are unlikely to have purely additive effects, resulting in increased levels of uncertainty.

Assessment of temporal trends in ecosystem health using an holistic indicator

The Ecosystem Approach to environmental management, with its explicit acknowledgment of the environmental, social and economic elements within ecological systems, is becoming increasingly adopted by managers and policy makers. However, there are few specific prescriptions as to exactly how these different elements should be integrated, or examples where historical changes have been tracked. Here, we assess the potential benefits and challenges of applying an Ecosystem Approach to management using one particular method, the Holistic Ecosystem Health Indicator (HEHI), which integrates data from the ecological, social and interactive dimensions into a single composite index of ecosystem 'health'. We apply it to one of the best-documented catchments in the UK, the Ythan Estuary in Aberdeenshire, Scotland, based on a 50-year time series of data. The evaluation of ecosystem health over time is lacking in previous applications of HEHI, yet is crucial for the assessment of the utility of this approach to ecosystem management. The application of HEHI yielded different insights to those revealed from the traditional application of biophysical approaches for managing the Ythan. Overall, ecological health declined through the 50-year period, although it increased marginally in the last decade, while social and interactive dimensions followed the opposite trend. HEHI indicated a steady increase in ecosystem health overall except for the last decade, when it declined marginally. Our evaluation of the application of ecosystem health for the Ythan revealed major data gaps. For the approach to be used more widely, issues of data availability and the temporal and geographical mismatch between ecological and social research boundaries need to be overcome.

The species-area relationship and confounding variables in a threatened monkey community

This study investigates the species-area relationship (SAR) for forest monkeys in a biodiversity hotspot. The Udzungwa Mountains of Tanzania are well-suited to investigate the SAR, with seven monkey species in a range of fragment sizes (0.06-526 km(2)). We test the relationship between species richness and forest fragment size, relative to human and environmental factors. We distinguish resident and transitory species because the latter have an "effective patch size" beyond the area of forest. Forest area was the strongest (log-linear) predictor of species richness. However, forest area, elevation range and annual moisture index were intercorrelated. Previous knowledge of the relationship between elevation and tree communities suggests that the SAR is largely a result of habitat heterogeneity. Isolation by farmland (matrix habitat) also had a significant negative effect on species richness, probably exacerbated by hunting in small forests. The effect of area and isolation was less for transitory species. The human influence on species' presence/absence was negatively related to the extent of occurrence. Weaker relationships with temperature and precipitation suggest underlying climatic influences, and give some support for the influence of productivity. A reduced area relationship for smaller forests suggests that fragment sizes below 12-40 km(2) may not be reliable for determining SAR in forest monkeys. Further practical implications are for management to encourage connectivity, and for future SAR research to consider residency, matrix classification and moisture besides precipitation.

Identifying conflicts and opportunities for collaboration in the management of a wildlife resource: a mixed-methods approach

ContextThe sustainable management of many common-pool ecological resources can be strengthened through collaboration among stakeholder groups. However, the benefits of collaborative management are often not realised because of conflicts of interest among stakeholders. Effective strategies for enhancing collaborative management require an understanding of the trade-offs that managers make between different management outcomes and an understanding of the socioeconomic and location-specific differences that drive these preferences. Approaches based on quantitative or qualitative methods alone often fail to reveal some of the underlying factors inhibiting collaboration. AimsOur aim was to understand the relative importance that private-sector deer managers attach to changes in the following three outcomes of deer management: deer numbers, deer-related road-traffic accidents (RTAs) and deer impacts on conservation woodlands. MethodsWe used a mixed-methods approach, combining choice-experiment methodology with qualitative analysis of focus-group discussions from 10 study regions throughout Britain. Key resultsOur results showed that most of the private-sector stakeholders responsible for deer-management decisions at the local level would prefer to see a future with fewer deer-related RTAs but do not want to see a future with lower deer population levels. This is especially the case for those stakeholders managing for sporting purposes and those that rely on deer as a financial resource. ConclusionsThe preferences of many private-sector stakeholders responsible for deer management are at odds with those of private landowners currently experiencing economic and conservation damage from deer, and with the aims of government and non-government bodies seeking to reduce grazing and browsing damage through lower deer densities. Similar barriers to collaborative management are likely to exist in any situations where ecological resources deliver an unequal distribution of benefits and costs among stakeholders. ImplicationsOvercoming barriers to collaboration requires enhanced understanding of how different collaborative mechanisms are viewed amongst the stakeholder community and how collaborative management can be promoted. More holistic approaches to deer management, which include greater public awareness, additional road-traffic speed restrictions and appropriate fencing, or perhaps include deer-population reduction as only one of a suite of mechanisms for delivering multiple benefits from the land, are likely to gain more support from private-sector stakeholders. Mixed-methods approaches can provide an important first step in terms of both quantifying preferences in relation to the management of ecological resources and enabling detailed insights into the motivations and behaviours underlying them.

Interdisciplinary approaches for the management of existing and emerging human - wildlife conflicts

Human–wildlife conflicts are increasing throughout the world, principally due to a combination of human population growth, increased pressure on land and natural resources and climate change. Many human–wildlife conflicts stem from differences in objectives between various stakeholder groups, especially where the wildlife in question is a resource that can be exploited for economic or cultural benefit, or where the conservation of wildlife is at odds with human population growth or development pressure. Conflicts can be exacerbated by an incomplete understanding of their causes and/or inappropriate intervention measures. Many traditional forms of intervention are also subject to increasing scrutiny and criticism from society. Here, we highlight the potential strategic benefits that can be made by an interdisciplinary approach to human–wildlife conflict situations, by integrating knowledge and understanding across the natural and social sciences. We also stress the potential tactical benefits from combining new approaches to management with more traditional ones. We emphasise the potential contribution of more recent developments in decision-making under conditions of limited data availability and uncertainty. Finally, we recommend that monitoring should play a more prominent role, both in assessing the role of stakeholder engagement in participatory decision-making and in contributing to the evidence base that will allow competing hypotheses about specific systems to be evaluated in an iterative manner.

Contact networks in a wildlife-livestock host community: identifying high-risk individuals in the transmission of bovine TB among badgers and cattle

BACKGROUND

The management of many pathogens, which are of concern to humans and their livestock, is complicated by the pathogens' ability to cross-infect multiple host species, including wildlife. This has major implications for the management of such diseases, since the dynamics of infection are dependent on the rates of both intra- and inter-specific transmission. However, the difficulty of studying transmission networks in free-living populations means that the relative opportunities for intra- versus inter-specific disease transmission have not previously been demonstrated empirically within any wildlife-livestock disease system.

METHODOLOGY/PRINCIPAL FINDINGS

Using recently-developed proximity data loggers, we quantify both intra- and inter-specific contacts in a wildlife-livestock disease system, using bovine tuberculosis (bTB) in badgers and cattle in the UK as our example. We assess the connectedness of individuals within the networks in order to identify whether there are certain 'high-risk' individuals or groups of individuals for disease transmission within and between species. Our results show that contact patterns in both badger and cattle populations vary widely, both between individuals and over time. We recorded only infrequent interactions between badger social groups, although all badgers fitted with data loggers were involved in these inter-group contacts. Contacts between badgers and cattle occurred more frequently than contacts between different badger groups. Moreover, these inter-specific contacts involved those individual cows, which were highly connected within the cattle herd.

CONCLUSIONS/SIGNIFICANCE

This work represents the first continuous time record of wildlife-host contacts for any free-living wildlife-livestock disease system. The results highlight the existence of specific individuals with relatively high contact rates in both livestock and wildlife populations, which have the potential to act as hubs in the spread of disease through complex contact networks. Targeting testing or preventive measures at high-contact groups and individuals within livestock populations would enhance the effectiveness and efficiency of disease management strategies.

Wildlife Research in a changing world

Wildlife populations on both land and in the sea are under increasing pressure from both direct and indirect anthropogenic impacts. Threats to wildlife, such as over-exploitation, habitat loss, invasive species, infectious disease and climate change persist; yet in some situations, wildlife populations are the subject of management to reduce their unwanted impacts on economic, agricultural and conservation interests. The contrasting requirements of declining and overabundant populations, sometimes existing as part of the same ecosystem, mean that wildlife management needs to be viewed increasingly as part of an integrated social–ecological system. Moreover, solutions to wildlife-management problems may require new combinations of ecological knowledge, technological innovation and an understanding of the social and economic factors involved. The disciplinary scope of Wildlife Research will be broadening to reflect these changes. Wildlife Research has tended to focus on terrestrial systems in the past, but research approaches and findings are increasingly relevant across different environments, and consequently, we will also be expanding our coverage of freshwater and marine systems. We are planning to publish at least one Special Issue each year, to highlight new areas of research and the increasing internationalisation of wildlife management, and we welcome suggestions for these. We are also pleased to be able to offer fast-track publication of papers that contain results of high topical significance or policy relevance. We hope that the increased topical, disciplinary and geographical coverage of Wildlife Research will enhance its position as one of the leading international journals in applied ecology and environmental management.

Control of bovine tuberculosis in British livestock: there is no 'silver bullet'

Bovine tuberculosis (bTB; Mycobacterium bovis) is a bacterial infection of cattle that also affects certain wildlife species. Culling badgers (Meles meles), the principal wildlife host, results in perturbation of the badger population and an increased level of disease in cattle. Therefore, the priority for future management must be to minimize the risk of disease transmission by finding new ways to reduce the contact rate among the host community. At the farm level, targeting those individuals that represent an elevated risk of transmission might prove to be effective. At the landscape level, risk mapping can provide the basis for targeted surveillance of the host community. Here, we review the current evidence for bTB persistence in Britain and make recommendations for future management and research.

Dynamic interactions among badgers: implications for sociality and disease transmission

1. Direct interactions between individuals play an important part in the sociality of group-living animals, their mating system and disease transmission. Here, we devise a methodology to quantify relative rates of proximity interaction from radio-tracking data and highlight potential asymmetries within the contact network of a moderate-density badger population in the north-east of England. 2. We analysed radio-tracking data from four contiguous social groups, collected over a 3-year period. Dynamic interaction analysis of badger dyads was used to assess the movement of individuals in relation to the movement of others, both within and between social groups. Dyads were assessed with regard to season, sex, age and sett use pattern of the badgers involved. 3. Intragroup separation distances were significantly shorter than intergroup separation distances, and interactions between groups were rare. Within groups, individuals interacted with each other more often than expected, and interaction patterns varied significantly with season and sett use pattern. Non-mover dyads (using the main sett for day-resting on > 50% of occasions) interacted more frequently than mover dyads (using an outlier sett for day-resting on > 50% of occasions) or mover-non-mover dyads. Interactions between group members occurred most frequently in winter. 4. Of close intragroup interactions (< 50 m separation distance), 88.6% were associated with a main sett and only 4.4% with outlier setts. Non-mover dyads and non-mover-mover dyads interacted significantly more often at the main sett than mover-only dyads. These results highlight the importance of the main sett to badger sociality and support the suggestion that badger social groups are comprised of different subgroups, in our case based on differential sett use patterns. 5. Asymmetries in contact structure within a population will affect the way in which diseases are transmitted through a social network. Assessment of these networks is essential for understanding the persistence and spread of disease within populations which do not mix freely or which exhibit heterogeneities in their spatial or social behaviour.

Selection of line-transect methods for estimating the density of group-living animals: lessons from the primates

We review the four major contemporary methods for estimating density of group-living animals from line-transect sampling: perpendicular modelling of group centers, perpendicular modelling of center of measurable individuals, strip transects and animal-observer distance. The efficacy of each method is evaluated to produce a simple selection guide. We review the literature and use field data from the Udzungwa Mountains, Tanzania. The review is relevant to all group-living animals; however, examples are drawn from the primates. Perpendicular methods have better mathematical justification than non-perpendicular methods. For perpendicular methods using detection function models, it is preferable to measure group location using center of measurable individuals, as group centers are hard to estimate. The assumptions of detection function models are often broken in poor visibility habitats or with unhabituated animals. Alternatively strip transects may be used where there are reliable data on group spread and/or visibility. Strip transects are also the most practical, along with the animal-observer method; however, the latter lacks mathematical justification. We conclude that there are arguments for continued use of all four methods. In certain situations the use of raw encounter rates may also be considered. The appropriate method is determined by minimizing bias and considering time, resources and field conditions.

Alien invasive vertebrates in ecosystems: pattern, process and the social dimension

The rate of biological invasions has increased dramatically over recent centuries. Alien invasive vertebrates have significant adverse effects on biodiversity, and island fauna are especially susceptible. Human-induced environmental change is likely to exacerbate these negative impacts of alien invasive species. However, invasion biology has advanced considerably over the last two decades, with improvement in understanding of the processes of establishment and spread. New developments in spatial modelling have elucidated the way in which behavioural processes at the individual level can drive population-level patterns such as spread. Combined with new genetic insights into the process of invasion, these advances may assist in the development of novel, better-targeted management strategies that provide new options in how to deal with the threat posed by invasive species. Decisions about whether to and how we should intervene are questions for all sectors of society, but research on the social and cultural impacts of invasive species is largely lacking. There are many opportunities for enhancing the social dimensions of invasive species research, and integrated assessments of the social, economic and environmental impacts of species provide one potential avenue. As part of this, there is also a need to increase stakeholder participation in the decision-making process regarding alien invasive species. These more holistic approaches are essential if we are to reduce the impact of alien invasive species to within acceptable limits in the face of rapid environmental change.

Wild deer as a source of infection for livestock and humans in the UK

Wild deer can feature in the epidemiology of a wide range of livestock and human diseases in the United Kingdom by representing a source of disease via various transmission routes. This review highlights current and possible future infections of deer in the UK which may have an impact on livestock and/or human health. Increases in deer abundance as well as range expansion are likely to exacerbate the potential for disease persistence due to the formation of multi-species deer assemblages, which may act as disease reservoirs. Climatic changes are likely to have a direct impact on the presence and abundance of various pathogens and their vectors, so that with a warming climate exotic diseases may play a role in future UK livestock and wildlife disease management. This paper highlights the need for a monitoring strategy for wildlife diseases, in particular infections in wild deer, in the UK.

Bovine tuberculosis in southern African wildlife: a multi-species host-pathogen system

This review examines the current situation of bovine tuberculosis (bTB) in southern African savannah systems, and uses theory on multi-species host-pathogen systems to suggest possible options for future research and management. In southern Africa, the buffalo (Syncerus caffer) and the Kafue lechwe [Marsh antelope] (Kobus leche) have been found to be maintenance hosts for this disease, but the importance of other host species is becoming apparent. The role of other host species in the maintenance and spread of the disease varies, depending on the spatial distribution and resource utilization patterns of the species, disease susceptibility, transmission modes and the ecology of both host(s) and vector(s). Future research needs to identify the pathogenicity of bTB in each of the host species, and the mechanisms and rates of inter- and intra-specific transmission among different species, in order to develop multi-host models to understand the development and spread of the disease.

The health of wild red and sika deer in Scotland: an analysis of key endoparasites and recommendations for monitoring disease

Monitoring the health of wildlife populations is important for understanding and controlling the risk of infections to livestock, humans and/or other wildlife. In this paper, we analyse the results of surveys of parasites and non-specific signs of diseases carried out on organs from 638 red and 107 sika deer culled in four regions of Scotland between 1991 and 1997. Infections of the lung by Elaphostrongylus spp. were significantly greater in red than sika deer. Older animals were more heavily infected with Elaphostrongylus spp. and Sarcocystis spp., and infections with Sarcocystis spp. tended to be heavier in more recent years. The results suggest that a combination of key indicator parasite species and non-specific signs of disease may be useful for monitoring the health of wildlife populations at a national scale. However, they also demonstrate that such monitoring needs to be long-term, carried out according to standard protocols and at an appropriate resolution to enable integration with data on other potentially influential environmental factors.

Mortality due to fox predation in free-range poultry flocks in Britain

Information derived from questionnaires sent to producers of free-range eggs, chickens, turkeys and geese was used to assess the extent of fox predation in terms of the density of the fox population and farm management factors. The mean reported bird mortality was less than 2 per cent for all the producers, but there were marked differences between them. Egg producers reported losing many more birds to foxes than other types of producer (up to 1000 birds in a laying cycle). On average, egg and goose producers lost the highest proportions of their total flocks (0.5 per cent). The extent of predation was not associated either with large-scale estimations of the density of the fox population or with variations in the farms' habitat. Chicken predation was not linked to differences in types of housing or fencing. However, there was a positive association between losses due to other causes and chicken predation. The results suggest that changes in farm management would be the most cost-effective means of reducing fox predation, rather than greater fox control.

Factors influencing the incidence and scale of bovine tuberculosis in cattle in southwest England

Bovine tuberculosis (TB) in cattle is a major economic problem in Britain. In the past 25 years, the infection has been concentrated in the southwest region of England. We investigated the effects of agricultural and farm-management characteristics on the occurrence and scale of TB in cattle in the region (1988-1996) using logistic and linear regression. Factors relating to the existence of previous infection in cattle and the management of cattle and badgers are all linked to the incidence of the infection--but those related specifically to the management of cattle are of overriding importance in determining the scale of the problem. Although our analysis was conducted at a large spatial scale, the results suggest that improvements to the procedure for testing and managing TB in cattle, reductions in cattle stocking density, a greater human input in herd management and more-carefully targeted badger culling all might contribute to reducing the incidence and/or number of herd breakdowns.

Modelling the costs of fox predation and preventive measures on sheep farms in Britain

Economic analysis is a useful tool to aid decisions on what to do about wildlife impacts, such as those of vertebrate predators on livestock farmers. The case-study of lamb predation by foxes in Britain is used to develop a theoretical economic model, with the aim of determining a financially optimal solution to minimise the total costs of livestock predation at the farm-level. Total costs include output losses and expenditure on preventive and control measures, in this case indoor housing and lethal fox control. The model is tested empirically with data from a questionnaire survey of sheep farmers and field data on fox population densities in Britain. Regression analyses are used to determine the relationships between lamb losses and expenditure on indoor housing, fox population density and other non-management characteristics. The effect of fox abundance on the cost of fox control is also assessed. Marginal analysis is used to determine the total cost-minimising solution from the farmer's point-of-view, in terms of how many ewes should be housed indoors and for how long, as well as how many foxes should be killed in addition to any lethal control already carried out. Optimal solutions vary according to farm characteristics, including flock size and the regional location of farms. In all cases, to minimise the costs of predation, as many ewes as possible should be housed. However, it is not worthwhile housing them for more than a day after lambing. Efficient fox predation management does not necessarily mean that lamb losses should be reduced to zero, and additional fox control is not worthwhile on the majority of farms. The analysis provides a framework for future evaluations of wildlife impacts and cost-effective management of these problems.

Population recovery of common brushtail possums after local depopulation

Brushtail possums (Trichosurus vulpecula) were live-trapped for two years prior to and following depopulation in two ~6-ha areas of native forest in New Zealand. The populations had recovered to 55% of the original density at one site and 40% of the original density at the other site, two years after the depopulation. The post-removal populations responded to reduced density with a higher proportion of females breeding, higher survival rate of young, and less seasonal fluctuation in body condition. The initial recolonisation was probably mainly due to surrounding animals shifting their ranges into the depopulated area, rather than long-range dispersal, which resulted in an even sex ratio in the recovering populations. The greater proportion of adult males in the post-removal populations is likely to increase sexual contact rates for females. This would enhance the dissemination of a viral-vectored biological control agent through the population, when used as part of an integrated control program.

The current and future management of wild mammals hunted with dogs in England and Wales

There is increasing concern about the use of lethal methods to control wild mammal populations, especially those methods that may have significant impacts on animal welfare. The continued use of dogs to hunt wild mammals in England and Wales, principally foxes (Vulpes vulpes), red deer (Cervus elaphus), brown hares (Lepus europaeus) and mink (Mustela vison), has become a focus for political debate and has been the subject of a recent UK government inquiry. This paper reports the results of a questionnaire study to quantify the use, effectiveness and acceptability of the different methods currently used to manage these four species, and future changes in management following a possible ban on hunting with dogs. There was no straightforward relationship between culling pressure and perceived pest status of the different species from the questionnaire data. For foxes and brown hares, the proportion of land managers (practitioners) carrying out lethal control was higher than that considering these species to be pests. However, the reverse was the case for mink. The most frequently used and effective control methods, which were most acceptable to practitioners and public alike, were various forms of shooting. The general public perceived hunting with dogs as one of the least acceptable means of control for all four species. Practitioners thought that hunting with dogs for red deer and the use of terriers against foxes were among the least acceptable forms of control, but considered hunting with dogs in other situations and for other species to be relatively acceptable. Most practitioners said a ban on hunting with dogs would make no difference to their management of the four species. A ban on hunting with dogs would have minimal impact on populations of foxes, red deer and mink, but it may be of conservation benefit to hares.

Factors associated with fox (Vulpes vulpes) predation of lambs in Britain

Red foxes (Vulpes vulpes) are believed to have an economic impact on farming through predation on lambs, poultry and game. Investigation of the causes behind variation in the impact of predation between farms is required to improve management of these problems. A questionnaire survey of sheep farmers was combined with field data on relative fox population abundance to investigate some of the factors associated with both the occurrence and scale of perceived fox predation in Britain. Reported lamb losses to foxes were generally low but there was a large range in perceived levels of predation, from 0.0008 to 0.26 lambs per ewe, with 59% of respondents reporting that they had lost at least one lamb to a fox at their most recent lambing. Flock size was an important factor determining perceived fox predation. Fox predation was more likely to have occurred on larger farms, but, when it did, fewer lambs were perceived lost per ewe. Various other non-management characteristics, including regional location, had an influence on fox predation. Fox abundance was positively associated with perceived predation. Indoor lambing was an important preventive measure against fox predation. However, the effect of fox control on livestock predation was difficult to determine because of potential reactive behaviour by farmers to lamb losses. The analyses indicate that multivariate rather than univariate techniques should be used in the assessment of predator impacts and in making management recommendations. The identification of farm characteristics associated with fox predation, such as location and indoor lambing, enables the potential identification of problem farms where preventive management should be targeted.

Spatial interactions and habitat use of rabbits on pasture and implications for the spread of rabbit haemorrhagic disease in New South Wales

Successful control of European rabbit (Oryctolagus cuniculus) populations in Australia has been achieved with the use of disease, initially myxomatosis and more recently rabbit haemorrhagic disease (RHD). Predicting the effectiveness of disease as a control agent depends on understanding the spatial and social organisation of its host population. We radio-tracked 37 rabbits from adjacent burrow systems during May and June 1999. Surface-dwelling rabbits had larger home ranges and core areas and a higher proportion of vegetation cover in their ranges than warren-based rabbits. Interactions between rabbit dyads from the same warren showed greater range overlap than those involving rabbits from different warrens and those involving itinerants. Static interaction was high and positive for intra-warren dyads, but low and negative for inter-warren, warren–surface and surface–surface dyads. These patterns of range use and interaction behaviour create a hierarchical contact and transmission structure within the rabbit population that is likely to vary according to external factors such as population density, resource availability, season, climate and the environment. Quantifying these links between the environment and the transmission process is important to increase our understanding of RHD as an effective management tool for rabbit populations.