Effects of agri-environmental habitat provision on winter and breeding season abundance of farmland birds

Farmland bird populations continue to show declines in spite of over 20 years of research and implementation of agri-environmental schemes (AES) intended to reverse this. Although it is well known that provision of winter food resources can attract farmland birds, there is continuing uncertainty over the ability of AES to provide tangible benefits for target species in terms of increased abundance. Answering these questions is hampered by interannual fluctuations in bird populations and the mobility and territoriality of farmland birds, which have complicated the interpretation of previous studies. We monitored birds for five years on a large arable estate in central England managed under varying levels of AES uptake (low level uptake of simple and widely applicable AES options, more extensive uptake of more complex AES options), and two control treatments (on-site and off-site). Bird abundance in winter and both total abundance and number of territories in the breeding season were calculated from monthly visits to 16 transects. Several species showed significantly higher winter abundance on AES treatments, particularly granivorous species (e.g. reed bunting, yellowhammer, linnet). Many other species (e.g. blackbird, chaffinch, robin) also showed significant differences in winter abundance between treatments on the estate and off-site controls. In the breeding season, linnet, reed bunting, goldfinch and combined granivorous birds showed higher abundance or number of territories on AES treatments compared to on-site controls. For most other species the differences were only significant between treatments on the estate and off-site controls. Independently of AES treatment, a lower coverage of cereals or greater Shannon diversity of crops in the local landscape also had a positive effect on the abundance of many species. Our results suggest that well-implemented AES can significantly enhance local populations of both farmland specialists of conservation concern and generalist species. Our results also show that, in many cases, these effects were only demonstrable at the farm scale, in comparison with off-site controls. This is probably due to high levels of movement and dispersal of birds resulting in a farm-scale spill-over of beneficial effects of agri-environment measures. Our results therefore highlight the importance of thinking beyond the single-farm scale when designing schemes or studies for monitoring the effectiveness of AES, and the importance of selecting appropriately located controls

Endothelin-1 stimulates oral fibroblasts to promote oral cancer invasion

AbstractAimsThe aims of this study were to examine the role of endothelin-1 (ET-1), a pleiotropic peptide found at elevated levels in a number of malignancies and which has been shown to influence oral cancer cell behaviour via paracrine signalling pathways, on the phenotype of oral fibroblasts.Main methodsThe effect of ET-1 on proliferation and migration of human primary oral fibroblasts was assessed using MTS and scratch assays, respectively. The ability of ET-1 to affect fibroblast contractility was analysed using type-I collagen gels. Changes in gene expression in oral fibroblasts exposed to ET-1 were examined using quantitative PCR. The invasiveness of oral cancer cells in the presence of conditioned media collected from ET-1 treated fibroblasts was determined using 2D Matrigel assays.Key findingsHere we provide evidence that ET-1 increases the migration of oral fibroblasts and induces a more contractile phenotype which is not associated with changes in gene expression indicative of myofibroblast transdifferentiation. In addition we provide evidence that conditioned medium of ET-1-stimulated oral fibroblasts promotes invasion of OSCC cells in vitro.SignificanceIn oral squamous cell carcinoma, a frequently fatal and increasingly common epithelial malignancy of the oral cavity, ET-1 is known to contribute to pro-migratory paracrine signalling between stromal fibroblasts and cancer cells. The ability of ET-1 to modulate the phenotype of human oral stromal fibroblasts, however, has not previously been reported. The findings presented here suggest that targeting the stromal endothelin system may be a viable and novel therapeutic strategy for invasive oral cancer

On bird species diversity and remote sensing – utilizing lidar and hyperspectral data to assess the role of vegetation structure and foliage characteristics as drivers of avian diversity

Avian diversity has long been used as a surrogate for overall diversity. In forest ecosystems, it has been assumed that vegetation structure, composition and condition have a significant impact on avian diversity. Today, these features can be assessed via remote sensing. This study examined how structure metrics from lidar data and narrowband indices from hyperspectral data relate with avian diversity. This was assessed in four deciduous-dominated woods with differing age and structure set in an agricultural matrix in eastern England. The woods were delineated into cells within which metrics of avian diversity and remote sensing based predictors were calculated. Best subset regression was used to obtain best lidar models, hyperspectral models and finally, the best models combining variables from both datasets. The aims were not only to examine the drivers of avian diversity, but to assess the capabilities of the two remote sensing techniques for the task. The amount of understorey vegetation was the best single predictor, followed by Foliage Height Diversity, reflectance at 830 nm, Anthocyanin Reflectance Index 1 and Vogelmann Red Edge Index 2. This showed the significance of the full vertical profile of vegetation, the condition of the upper canopy, and potentially tree species composition. The results thus agree with the role that vegetation structure, condition and floristics are assumed to have for diversity. However, the inclusion of hyperspectral data resulted in such minor improvements to models that its collection for these purposes should be assessed critically

Bioenergetics of desert birds (Sandgrouse : Peteroclididae)

SIGLEAvailable from British Library Document Supply Centre- DSC:DX173251 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Ash dieback: long-term monitoring of impacts on biodiversity

The overall objective of this study was to scope-out the options for a long-term monitoring strategy of the impacts of ash dieback on biodiversity in the UK. This objective was addressed using a 3-day facilitated workshop at CEH Wallingford, bringing together expertise from CEH, various NGOs and the statutory agencies. The main questions addressed were: (1) What are the monitoring needs for ash dieback? (2) How suitable are existing surveys? (3) How does current monitoring need to be enhanced or extended

Great tits Parus major and blue tits Cyanistes caeruleus as indicators of agri-environmental habitat quality

This study examined relationships between habitat and breeding success for two common bird species, the great tit Parus major and blue tit Cyanistes caeruleus. The aim was to determine the potential of these species to act as indicators of food resource availability for birds in managed semi-natural habitats on farmland and thus as a measure of the effectiveness of specific management practices under agri-environment schemes (AES). Breeding success was recorded for four years (2007–2010) using 90 nestboxes on arable farmland in central England. Habitat parameters were derived from high spatial resolution airborne Light Detection and Ranging (LiDAR) and hyperspectral data. Relationships of breeding variables with a range of habitat variables, many of which were influenced by AES management, were evident for both species, despite strong interannual variation in breeding parameters. Relationships were strongest for models using habitat variables within a 100 m radius of the nest, compared to values of 50 and 200 m. Both species showed significant, positive relationships with the area and proximity of tree canopy and, for great tits especially, with hedgerow height and volume. Therefore, tits may act as indicators of the quality of local habitat, particularly within-hedge trees and hedgerows, managed under agri-environmental provision, and provide insight into the spatial arrangement of AES options at the field scale

Modelling the third dimension: Incorporating topography into the movement rules of an individual-based spatially explicit population model

A wide variety of topographical and environmental elements have been shown or proposed to influence the movement decisions of dispersing animals. Most real landscapes have topographical elements such as hills, valleys and urban developments, which can all act to modify a species’ perceptual range and directly influence movement behaviour. If a visual-based perceptual ability enables a dispersing individual to locate suitable habitat patches at a distance, then it is to be expected that topographical features would act to modify the overall success of this strategy. However, the majority of individual-based Spatially Explicit Population Models (SEPM) employ only two-dimensional landscapes. To investigate the effects of topographical elevation on dispersal patterns, a three-dimensional visual-based perceptual range algorithm was added to the dispersal rules of an individual-based SEPM. To explore the possible influences of a behavioural-based response to topography, an algorithm modelling valley-seeking behaviour was also developed. The performance of both algorithms was compared with that of a two-dimensional visual-based perceptual range algorithm. The overall consequences of dispersal under each algorithm were measured by recording population sizes in a target wood in the centre of a modelled, real landscape. The size of the population in the target wood, modelled using both of the three-dimensional algorithms, exhibited sensitivity to the direction of dispersal in interaction with perceptual range, which differed from that predicted by the two-dimensional approach. Population size was dependant on the spatial configuration of habitat patches and on the topography of the landscape, both of which could guide dispersers either towards or away from the target patch depending on the particular combinations of dispersal directions and perceptual ranges selected. Topography was found to have a greater effect on dispersal at shorter perceptual ranges, and thresholds in the results for all three algorithms suggested the existence of species and landscape dependant optimal perceptual ranges. It is recommended that both topography and topographical-based dispersal-altering algorithms, commensurate with the studied species’ behaviour, be incorporated into the movement rule-base of dispersal simulation models. The modelling of topography and its effects on movement in patchy landscapes are seen as essential ingredients in future landscape planning

Geographical and land-use influences on bird species richness in small woods in agricultural landscapes

In this paper we examine the influence of geographical and land-use factors on breeding bird species richness in small woods within farmland. In many European agricultural landscapes, small woods represent the major component of semi-natural habitat available to wildlife. We used census data (for woods of up to 15 ha) from six study areas in four countries (The Netherlands, UK, Denmark and Norway) to construct species-area relationships for woodland birds. An additional relationship for Sweden was obtained from the literature. Species richness, and the parameters of the species-area relationships, were then related to the latitude, longitude and percentage woodland cover of each study area. Overall, species richness across all woods in each study area declined with increasing latitude; the proportion of resident species also declined, but that of migrants increased. Numbers of migrant species also increased with increasing woodland cover. Both the slopes and intercepts of the species-area relationships declined with increasing latitude. Thus not only were fewer species available to colonise individual woods at higher latitudes, but the return in terms of species richness for a given increase in area was also less than at lower latitudes. From the species-area relationships, the numbers of species expected to breed in woods of 1 ha and of 15 ha decreased from 13 and 21, respectively, in The Netherlands (latitude 51.7°) to 7 and 13, respectively, in Denmark (latitude 56.3°). Other factors influencing species richness on both local and geographical scales are discussed

Performance and effectiveness of winter bird food patches established under Environmental Stewardship: results from the Hillesden experiment

The Hillesden experiment is a farm-scale study evaluating the performance of options under Environmental Stewardship. We describe bird usage of winter seed patches (20 patches; three seed mixes) in relation to seed depletion and variation between individual patches. Seed retention declined exponentially in all three mixes; 50% depletion occurred by late November, reaching 80-90% before mid January. In mid winter, Fodder Beet retained more seed (c. 80%) than Millet, Kale, Fodder Radish and Triticale (20-40%). Bird numbers peaked in December/early January (seed depletion 70-90%), but declined rapidly in late January coinciding with seed exhaustion. Seed yields varied between patches (minimum < 1% of maximum). If all patches had performed at the maximum, yield would have increased by about 64%. Bird counts also varied greatly between patches, but trends with seed yield were positive. At a farm-scale, winter bird abundance was significantly greater (granivorous species + 415%) when patches were available