The landscape ecology of brown hares and European rabbits in pastures in the north east of England

The declines of the brown hare (Lepus europaeus), a priority species for conservation in the UK, may have been caused by changes in agricultural management. This study aims to identify hare distribution, density, habitat selection and demography in grasslands in order to benefit their future conservation. In addition, this study aims to investigate the impact of current agricultural management on the populations of the European wild rabbit (Oryctolagus cuniculus), a major agricultural pest and potential competitor for hares. Hare and rabbit populations were surveyed in several large, pasture-dominated, sites in north–east England between 2007 and 2009. Estimated density of brown hares in the studied region was far higher than the published national average density for this species in pastures but with very large variation between superficially similar sites. We explored a new method to survey hares using night-time line transect distance sampling and compared this method with day time surveys. Night-time distance sampling produced improved precision estimates of hares with considerably less survey effort by maximising detectability during surveys. Hares and rabbits had different habitat requirements in grassland areas and areas dominated by intensive sheep grazing produced the lowest hare densities and in most cases were associated with high rabbit densities. Field size was an important determinant of the distribution of both hares and rabbits but with contrasting effects for the two species. Predator control appeared more important in increasing rabbit numbers than hares in the studied region. Our results indicate that recent changes in pasture management in the UK might favour high rabbit densities with potentially significant economic impacts for the agricultural sector. Hare productivity was high but female fertility and survival, in particular juvenile survival, were relatively low. Hares in the studied region were generally in good condition and reached sizes comparable with hares from arable areas. Population modelling suggested the hare population in the area was slowly increasing but was susceptible to decline even at relatively moderate levels of hunting. Radio-tracking indicated that habitat heterogeneity was important for hares at both between and within field levels. Hares preferentially used field margins during both active and inactive periods and selected woodland edges and unimproved grassland during diurnal periods, suggesting that they might benefit from measures designed to increase heterogeneity and re-establishment of non-farmed habitat features, particularly field margins. Equally, hares avoided sheep grazed fields with short swards for both foraging and resting indicating that reducing grazing intensity in pastural areas would also be beneficial for hare conservation. We suggest that grassland management could be adapted in order to minimize damage by high numbers of rabbits and increase the presence and abundance of the brown hare, a species of conservation concern in Europe and the UK

The landscape ecology of brown hares and European rabbits in pastures in the north east of England

The declines of the brown hare (Lepus europaeus), a priority species for conservation in the UK, may have been caused by changes in agricultural management. This study aims to identify hare distribution, density, habitat selection and demography in grasslands in order to benefit their future conservation. In addition, this study aims to investigate the impact of current agricultural management on the populations of the European wild rabbit (Oryctolagus cuniculus), a major agricultural pest and potential competitor for hares. Hare and rabbit populations were surveyed in several large, pasture-dominated, sites in north–east England between 2007 and 2009. Estimated density of brown hares in the studied region was far higher than the published national average density for this species in pastures but with very large variation between superficially similar sites. We explored a new method to survey hares using night-time line transect distance sampling and compared this method with day time surveys. Night-time distance sampling produced improved precision estimates of hares with considerably less survey effort by maximising detectability during surveys. Hares and rabbits had different habitat requirements in grassland areas and areas dominated by intensive sheep grazing produced the lowest hare densities and in most cases were associated with high rabbit densities. Field size was an important determinant of the distribution of both hares and rabbits but with contrasting effects for the two species. Predator control appeared more important in increasing rabbit numbers than hares in the studied region. Our results indicate that recent changes in pasture management in the UK might favour high rabbit densities with potentially significant economic impacts for the agricultural sector. Hare productivity was high but female fertility and survival, in particular juvenile survival, were relatively low. Hares in the studied region were generally in good condition and reached sizes comparable with hares from arable areas. Population modelling suggested the hare population in the area was slowly increasing but was susceptible to decline even at relatively moderate levels of hunting. Radio-tracking indicated that habitat heterogeneity was important for hares at both between and within field levels. Hares preferentially used field margins during both active and inactive periods and selected woodland edges and unimproved grassland during diurnal periods, suggesting that they might benefit from measures designed to increase heterogeneity and re-establishment of non-farmed habitat features, particularly field margins. Equally, hares avoided sheep grazed fields with short swards for both foraging and resting indicating that reducing grazing intensity in pastural areas would also be beneficial for hare conservation. We suggest that grassland management could be adapted in order to minimize damage by high numbers of rabbits and increase the presence and abundance of the brown hare, a species of conservation concern in Europe and the UK

Identifying pathways of exposure to highway pollutants in great crested newt (Triturus cristatus) road mitigation tunnels: Exposure pathways of highway pollutants to Triturus cristatus

Road mitigation tunnels are increasingly deployed for amphibians but very little is known about chemical pollution in such schemes. We assessed pollution pressures associated with road runoff at a major great crested newt mitigation scheme in England. Sediments and waters in the mitigation system were analysed for major physico-chemical parameters, trace metals and total petroleum hydrocarbons and compared to a nearby reference site. Seven out of eight tested metals including copper, zinc, lead and iron were in significantly greater concentrations in the tunnels than at a reference site and at environmentally significant concentrations. Water samples also exhibited elevated concentrations of aluminium and chromium and occasionally extreme alkaline pH associated with leaching of portlandite in tunnel cements. High conductivity values in waters and sediments corresponding with seasonal de-icing salt application were also apparent. The study highlights the potential pollutant pressures for amphibians associated with large-scale urban development and road mitigation schemes

Effectiveness of small road tunnels and fences in reducing amphibian roadkill and barrier effects at retrofitted roads in Sweden.

Schemes to reduce road impacts on amphibians have been implemented for decades in Europe, yet, several aspects on the effectiveness of such schemes remain poorly understood. Particularly in northern Europe, including Sweden, there is a lack of available information on road mitigation for amphibians, which is hampering implementation progress and cost-effectiveness analyses of mitigation options. Here, we present data derived from systematic counts of amphibians during spring migration at three previous hot-spots for amphibian roadkill in Sweden, where amphibian tunnels with guiding fences have been installed. We used the data in combination with a risk model to estimate the number of roadkills and successful crossings before vs. after mitigation and mitigated vs. adjacent non-mitigated road sections. In mitigated road sections, the estimated number of amphibians killed or at risk of being killed by car traffic decreased by 85-100% and the estimated number successfully crossing the road increased by 25-340%. Data, however, suggested fence-end effects that may moderate the reduction in roadkill. We discuss possible explanations for the observed differences between sites and construction types, and implications for amphibian conservation. We show how effectiveness estimates can be used for prioritizing amphibian passages along the existing road network. Finally, we emphasize the importance of careful monitoring of amphibian roadkill and successful crossings before and after amphibian passages are constructed

Synthetic Biology Policy Recommendations

This submission of evidence aims to address some aspects of the following questions: - What are the key biological security opportunities, challenges, threats and vulnerabilities facing the UK (now and in 5 years)? - How should the government prioritise its efforts to identify and respond to these

Detectability counts when assessing populations for biodiversity targets.

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

Volunteer Conservation Action Data Reveals Large-Scale and Long-Term Negative Population Trends of a Widespread Amphibian, the Common Toad (Bufo bufo).

Rare and threatened species are the most frequent focus of conservation science and action. With the ongoing shift from single-species conservation towards the preservation of ecosystem services, there is a greater need to understand abundance trends of common species because declines in common species can disproportionately impact ecosystems function. We used volunteer-collected data in two European countries, the United Kingdom (UK) and Switzerland, since the 1970s to assess national and regional trends for one of Europe's most abundant amphibian species, the common toad (Bufo bufo). Millions of toads were moved by volunteers across roads during this period in an effort to protect them from road traffic. For Switzerland, we additionally estimated trends for the common frog (Rana temporaria), a similarly widespread and common amphibian species. We used state-space models to account for variability in detection and effort and included only populations with at least 5 years of data; 153 populations for the UK and 141 for Switzerland. Common toads declined continuously in each decade in both countries since the 1980s. Given the declines, this common species almost qualifies for International Union for the Conservation of Nature (IUCN) red-listing over this period despite volunteer conservation efforts. Reasons for the declines and wider impacts remain unknown. By contrast, common frog populations were stable or increasing in Switzerland, although there was evidence of declines after 2003. "Toads on Roads" schemes are vital citizen conservation action projects, and the data from such projects can be used for large scale trend estimations of widespread amphibians. We highlight the need for increased research into the status of common amphibian species in addition to conservation efforts focusing on rare and threatened species

Terrestrial or marine species distribution model: Why not both? A case study with seabirds.

Funder: Arcadia FundFunder: MAVA FoundationSpecies reliant on both the terrestrial and marine realms present a challenge for conventional species distribution models (SDMs). For such species, standard single-realm SDMs may omit key information that could result in decreased model accuracy and performance. Existing approaches to habitat suitability modeling typically do not effectively combine information from multiple realms; this methodological gap can ultimately hamper management efforts for groups such as seabirds, seals, and turtles. This study, for the first time, jointly incorporates both terrestrial information and marine information into a single species distribution model framework. We do this by sampling nearby marine conditions for a given terrestrial point and vice versa using parameters set by each species' mean maximum foraging distance and then use standard SDM methods to generate habitat suitability predictions; therefore, our method does not rely on post hoc combination of several different models. Using three seabird species with very different ecologies, we investigate whether this new multi-realm approach can improve our ability to identify suitable habitats for these species. Results show that incorporating terrestrial information into marine SDMs, or vice versa, generally improves model performance, sometimes drastically. However, there is considerable variability between species in the level of improvement as well as in the particular method that produces the most improvement. Our approach provides a repeatable and transparent method to combine information from multiple ecological realms in a single SDM framework. Important advantages over existing solutions include the opportunity to, firstly, easily combine terrestrial and marine information for species that forage large distances inland or out to sea and, secondly, consider interactions between terrestrial and marine variables.This work has been funded by Stichting Ave Fenix Europa. NP is funded by Research England; SOP and WJS were funded by Arcadia, The David and Claudia Harding Foundation and MAVA Foundatio

What Works in Conservation 2021

This book provides an assessment of the effectiveness of 2526 conservation interventions based on summarized scientific evidence. The 2021 edition contains substantial new material on bat conservation, terrestrial mammal conservation and marine and freshwater mammals, thus completing the evidence for all mammal species categories. Other chapters cover practical global conservation of primates, amphibians, bats, birds, forests, peatlands, subtidal benthic invertebrates, shrublands and heathlands, as well as the conservation of European farmland biodiversity and some aspects of enhancing natural pest control, enhancing soil fertility, management of captive animals and control of freshwater invasive species. It contains key results from the summarized evidence for each conservation intervention and an assessment of the effectiveness of each by international expert panels. The accompanying website www.conservationevidence.com describes each of the studies individually, and provides full references. This is the sixth author-approved edition of What Works in Conservation, which is revised on an annual basis

The effect of rainfall upon the behaviour and use of under-road culverts in four amphibian species

This is a pre-copyedited, author-produced PDF of an article accepted for publication in Bioscience Horizons following peer review. The version of record Gleeson T., Petrovan S., & Muir A. P. (2018). The effect of rainfall upon the behaviour and use of under-road culverts in four amphibian species. Bioscience Horizons, 11, 1–10, is available online at: https://doi.org/10.1093/biohorizons/hzz001Habitat fragmentation and road mortalities are major contributors towards declines in amphibian populations. This has seen the introduction of culverts, passages that run under roads and provide safe passage for amphibians. Research investigating the effects of rainfall upon amphibian culvert use is limited. This study, conducted at Frankfield Loch in Glasgow, assesses how time elapsed since rainfall influences migration behaviour and the use of culverts across four different species; common toads (Bufo bufo), common frogs (Rana temporaria and newts, a group composed of smooth newts (Lissotriton vulgaris) and palmate newts (Lissotriton helveticus). Analysis of images taken by a custom made, time lapse camera found that significantly fewer common toads (r = 0.148, n = 468, p = 0.001) and common frogs (r = −0.175, n = 106, p = 0.037) used the culvert as time since rainfall increased. This may have been caused by the culvert not maintaining wet enough conditions for amphi- bians. The study also found that more newts (r = 0.272, n = 92, p = 0.004) and common toads (r = 0.531, n = 19, p = 0.010) were using the culvert to move away from Frankfield Loch as time since rainfall increased. An increase in juvenile newts was also observed as time since rainfall increased (r = 0.214, n = 92, p = 0.020). This may have been caused by a decrease in baro- metric pressure, which follows a decrease in rainfall, acting as a cue for migration and juvenile dispersal. The study recom- mends careful consideration of the design of each culvert, incorporating species-specific preferences and the requirements of juveniles. The study also suggests that where possible the culvert should be designed to hold water for longer