Philip Wheeler

Farming for pests? Local and landscape-scale effects of grassland management on rabbit densities

In recent decades in the UK, there has been an increasing trend in numbers of the European wild rabbit, a significant agricultural pest typically associated with grassland habitats. However, the relationship between rabbit abundance and grassland management, in particular grazing, has not been sufficiently explained. We studied rabbit densities in seven pasture-dominated sites in north-east England between autumn and spring in two consecutive years, and used generalised linear mixed models and generalised additive models to explore relationships between habitat and management variables and rabbit abundance at local (field) and landscape scales. At the local scale high rabbit densities were significantly associated with small fields and the very short, homogeneous swards created by intensive sheep grazing during autumn and winter. At the landscape scale, high rabbit numbers were associated with sites with most field margins and a predator removal policy. Our results indicate that landscape management may play a central role in explaining rabbit abundance and distribution in grasslands. We suggest that current pasture management may create favourable conditions for high rabbit densities, and consequently boost numbers of this significant pest species.

The relationship between diver experience levels and perceptions of attractiveness of artificial reefs - examination of a potential management tool.

Artificial reefs are increasingly used worldwide as a method for managing recreational diving since they have the potential to satisfy both conservation goals and economic interests. In order to help maximize their utility, further information is needed to drive the design of stimulating resources for scuba divers. We used a questionnaire survey to explore divers’ perceptions of artificial reefs in Barbados. In addition, we examined reef resource substitution behaviour among scuba divers. Divers expressed a clear preference for large shipwrecks or sunken vessels that provided a themed diving experience. Motives for diving on artificial reefs were varied, but were dominated by the chance of viewing concentrated marine life, increased photographic opportunities, and the guarantee of a ‘good dive’. Satisfaction with artificial reef diving was high amongst novices and declined with increasing experience. Experienced divers had an overwhelming preference for natural reefs. As a management strategy, our results emphasize the capacity of well designed artificial reefs to contribute towards the management of coral reef diving sites and highlight a number of important areas for future research. Suggested work should validate the present findings in different marine tourism settings and ascertain support of artificial reefs in relationship to level of diver specialization.

The diet of field volesMicrotus agrestis at low population density in upland Britain

Studies on field volesMicrotus agrestis Linnaeus, 1758 in lowland grasslands have shown them to be unselective grazers. The diet of the field vole in upland Britain was investigated using feeding trials with four of the dominant British upland monocots,Molinia caerulea,Nardus stricta, Deschampsia flexuosa and Eriophorum vaginatum. The suitability of faecal analysis was assessed and then used to analyse the diet of wild voles from faecal samples. Percentages of plant species in the faeces were compared to percentages on the ground in sites dominated byMolinia caerulea, Eriophorum vaginatum,Nardus stricta andCalluna vulgaris. Significant preferences for the grassDeschampsia flexuosa were observed in feeding trials and in the wild while the sedgeEriophorum vaginatum was avoided in both. There was no clear preference forMolinia caerulea andNardus stricta. Preference for plant species was related to palatability and nutrient content. The low nutrient conditions in British uplands mean that voles that live in these environments must be selective feeders to maximise nutrient intake.

Facilitating permeability of landscapes impacted by roads for protected amphibians: patterns of movement for the great crested newt

Amphibian populations are highly vulnerable to road mortality and habitat fragmentation caused by road networks. Wildlife road tunnels are considered the most promising road mitigation measure for amphibians yet generally remain inadequately monitored, resulting in mixed success rates in the short-term and uncertain conservation benefits in the long-term. We monitored a complex multi-tunnel and fence system over five years and investigated the impact of the scheme on movement patterns of two newt species, including the largest known UK population of the great crested newt (Triturus cristatus), a European Protected Species. We used a stage descriptive approach based on capture positions to quantify newt movement patterns. Newt species successfully used the mitigation but the system constituted a bottleneck to movements from the fences to the tunnels. Crossing rates varied widely among years and were skewed towards autumn dispersal rather than spring breeding migration. There was a substantial negative bias against adult male great crested newts using the system. This study indicates that road tunnels could partially mitigate wider connectivity loss and fragmentation at the landscape scale for newt species. However, the observed bottleneck effects and seasonal bias could have population-level effects which must be better understood, especially for small populations, so that improvements can be made. Current requirements for monitoring mitigation schemes post-implementation are probably too short to assess their effectiveness in maintaining connectivity and to adequately understand their population-level impacts.

Artificial reefs and marine protected areas: a study in willingness to pay to access Folkestone Marine Reserve, Barbados, West Indies

Artificial reefs in marine protected areas provide additional habitat for biodiversity viewing, and therefore may offer an innovative management solution for managing for coral reef recovery and resilience. Marine park user fees can generate revenue to help manage and maintain natural and artificial reefs. Using a stated preference survey, this study investigates the present consumer surplus associated with visitor use of a marine protected area in Barbados. Two hypothetical markets were presented to differentiate between respondents use values of either: (a) natural reefs within the marine reserve or (b) artificial reef habitat for recreational enhancement. Information was also collected on visitors’ perceptions of artificial reefs, reef material preferences and reef conservation awareness. From a sample of 250 visitors on snorkel trips, we estimate a mean willingness to pay of US

Detectability Counts when Assessing Populations for Biodiversity Targets

18.33 (median—US

Government subsidized by academia on conservation.

15) for natural reef use and a mean value of US

Distribution and status of threatened and endemic marsupials on the offshore islands of south-east Sulawesi, Indonesia

17.58 (median—US

Ecology, Evolution and Behaviour of Wild Cattle: Anoas Bubalus depressicornis (C. H. Smith, 1827); Bubalus quarlesi (Ouwens, 1910)

12.50) for artificial reef use. The number of marine species viewed, age of respondent, familiarity with the Folkestone Marine Reserve and level of environmental concern were statistically significant in influencing willingness to pay. Regression analyses indicate visitors are willing to pay a significant amount to view marine life, especially turtles. Our results suggest that user fees could provide a considerable source of income to aid reef conservation in Barbados. In addition, the substantial use value reported for artificial reefs indicates a reef substitution policy may be supported by visitors to the Folkestone Marine Reserve. We discuss our findings and highlight directions for future research that include the need to collect data to establish visitors’ non-use values to fund reef management.

Effects of sheep grazing on abundance and predators of field vole (Microtus agrestis) in upland Britain

Efficient, practical and accurate estimates of population parameters are a necessary basis for effective conservation action to meet biodiversity targets. The brown hare is representative of many European farmland species: historically widespread and abundant but having undergone rapid declines as a result of agricultural intensification. As a priority species in the UK Biodiversity Action Plan, it has national targets for population increase that are part of wider national environmental indicators. Previous research has indicated that brown hare declines have been greatest in pastural landscapes and that gains might be made by focussing conservation effort there. We therefore used hares in pastural landscapes to examine how basic changes in survey methodology can affect the precision of population density estimates and related these to national targets for biodiversity conservation in the UK. Line transects for hares carried out at night resulted in higher numbers of detections, had better-fitting detection functions and provided more robust density estimates with lower effort than those during the day, due primarily to the increased probability of detection of hares at night and the nature of hare responses to the observer. Hare spring densities varied widely within a single region, with a pooled mean of 20.6 hares km−2, significantly higher than the reported national average of hares in pastures of 3.3 hares km−2. The high number of encounters allowed us to resolve hare densities at site, season and year scales. We demonstrate how survey conduct can impact on data quantity and quality with implications for setting and monitoring biodiversity targets. Our case study of the brown hare provides evidence that for wildlife species with low detectability, large scale volunteer-based monitoring programmes, either species specific or generalist, might be more successfully and efficiently carried out by a small number of trained personnel able to employ methods that maximise detectability.