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McMahon, Barry J.
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McMahon, Barry J.
Official Name
McMahon, Barry J.
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Now showing 1 - 10 of 20
- PublicationSurvey evaluation for species richness of farmland birds(Birdwatch Ireland, 2012-12)
; ; ; ; To estimate biodiversity it may be important to establish whether increased data can be obtained from repeated surveys. Bird species richness was determined after repeated surveys in winter and in the breeding season. Data were collected over two breeding seasons and two winter seasons at nine sites, with three surveys in each winter and four surveys in each breeding season using a standard method. Poisson models were used to determine differences in total cumulative species richness recorded after each additional survey. There were significant increases in species richness in winter between survey one and survey two and between survey two and survey three across nine sites. There was a significant increase between survey one and survey two for resident breeding species richness. Based on pure species richness, three surveys recorded at least 95% of the total observed species richness recorded after four surveys in the breeding season within the agricultural survey area.328 - PublicationEvaluation of Red Grouse (Lagopus lagopus scoticus) habitat in the Connemara National ParkThe Red Grouse is a red-listed species and as such is of conservation concern in Ireland. These species are typically breeding birds which have been in rapid decline over the last 25 years or whose populations have been severely reduced over the last 100 years (Newton et al. 1999). This study investigated the habitats that were utilised by grouse in the Connemara National Park from mid June to August 2005. Three sites were surveyed within the Park, each covering an area of 250m x 250m. Two of these sites contained evidence of grouse utilising the area (such as feathers and droppings) and a control site containing no evidence of utilisation by grouse. Each of the sites was surveyed for heather percentage cover, maximum heather height and growth form as well as its invertebrate fauna. Grouse diet was also studied by analysis of droppings. The percentage cover of heather and the maximum heather height on the sites with grouse was found to be higher than that of the control site. The total numerical abundances of ground beetles (Order Coleoptera, Family Carabidae), per site were not significantly different but differences were apparent among other invertebrate groups between the control and the sites with grouse. Analysis of the droppings showed that their diet consisted mostly of Ling Heather which made up 84% of all fragments in the droppings. Bell Heather and Cross-leaved Heath were the next most abundant items with 4.4% and 2.2% respectively. Material other than heather constituted 1.4% of the diet with the remaining 8.2% of the fragments remaining unidentified.
461 - PublicationRegional and farm system drivers of avian biodiversity within agriculture ecosystems(Association of Applied Biologists, 2013-12)
; ; ; ; Farm-wide bird surveys were carried out on 119 grass-based farms located in three separate regions in Ireland during the winter and breeding seasons. Data relating to livestock production system (dairy or non-dairy) and participation in the Irish agrienvironment scheme (AES) at the time, the Rural Environmental Protection Scheme, were collected. GLMMs were used to establish the factors influencing bird populations during the winter and breeding season. Region and farming system had significant effects on avian biodiversity and there were frequently greater numbers on more intensively managed dairy farms, compared with less intensive non-dairy farms. AES participation had no significant effect on bird populations. Our findings demonstrate a clear influence of region and farm system on avian biodiversity, and suggest that the greater resource availability in more intensive farm systems may actually be beneficial for certain components of farmland biodiversity.849 - PublicationIrish agriculture and farmland birds, research to date and future prioritiesOf the total land area of Ireland, 62% is devoted to agricultural production, thus highlighting the importance of this land use to biodiversity. European farmland birds have experienced rapid decline in the last thirty years. This is emphasised by the fact that lowland farmland provides breeding or wintering habitat to over 120 bird species of European Conservation Concern and this constitutes the largest number supported by any habitat. Of the18 species of birds that are of high conservation concern in Ireland, 13 are associated with agricultural habitats. Extensive research has been carried out in the UK and Europe to establish the cause and how to reverse the decline in farmland birds. A limited amount of work has been carried out in Ireland; however more work is required as it cannot be assumed that findings relating to the farmland bird ecology in the UK and Europe will apply in the Irish situation. It is apparent that extensification of agriculture through the vehicle of agri-environmental schemes is the method of choice to reverse the declines in bird diversity in farmland both in Europe and Ireland. It is the responsibility of policy, conservation and agricultural production agencies to embrace these schemes in order to optimise production and reverse the declines in Irish farmland birds.
1614 - PublicationThe impact of farming on over-wintering bird populations(Faculty of Agriculture, UCD in association with Teagasc, 2003)
; ; ; Field boundaries and fields in stubble, set-aside, winter wheat and improved grassland in County Kildare were surveyed for birds on 15 occasions between October 2001 and February 2002. A total of 40 species was recorded on all sites during the period of the study. Arable farming that retains stubble throughout the winter supports the greatest species richness and diversity with the lowest being recorded on improved grassland. Individual species showed preference for certain sites. Seed-feeding species, yellowhammer and skylark, preferred stubble while invertebrate-feeding species, fieldfare and meadow pipit preferred grassland. The analysis demonstrated that certain components of habitat were responsible for differences in species present and density.238 - PublicationSquirrelpox virus reservoir expansion on the east coast of Ireland(Springer, 2015-03-03)
; ; ; ; ; ; The European red squirrel (Sciurus vulgaris) has suffered a 20 % decline in range in Ireland since the introduction of the eastern grey squirrel (Sciurus carolinensis) in 1911. In the UK, squirrelpox virus (SQPV) has been identified as being a major contributor to the decline of red squirrel populations but has only recently been confirmed in a red squirrel from Wicklow in Ireland with anecdotal references to a previous outbreak in the Shankill area of south County Dublin and a case in Kilmacanogue, north County Wicklow. The current study examined a sample of grey squirrels from these areas for SQPV seroprevalence. Enzyme-linked immunosorbent assay (ELISA) tests were carried out on sera from 51 grey squirrels culled from two sites in south County Dublin, areas A and B, and a third site in north County Wicklow, area C. The results indicated declining SQPV seroprevalence rates moving northwards from Wicklow, 55 % in area C, 50 % in area B and 11 % in area A. The low levels of seropositivity in Killiney (A) suggest that this is the wave-front of grey squirrel expansion from Wicklow and that the population may not yet have reached the threshold density for SQPV transmission to the red squirrel population to occur. The results of this study indicate that there is potential overlap between seropositive grey squirrel populations and susceptible red squirrel populations with obvious implications for conservation and management.342Scopus© Citations 1 - PublicationAn assessment of bird species within Irish agricultural landscapes using the Field Boundary Evaluation and Grading System.(Taylor & Francis, 2010-02-04)
; ; ; Capsule The Field Boundary Evaluation and Grading System (FBEGS) is a useful predictor of bird populations found in field boundaries located in southeast Ireland. Aims To assess the potential of FBEGS to evaluate the ecological quality of field boundaries in agricultural ecosystems and as a tool for the measurement of bird populations within field boundaries. Methods Surveys of bird populations were made in selected field boundaries on 50 farms in southeast Ireland in winter and during the breeding season. FBEGS surveys were also carried out on field boundaries to assess ecological quality. glms were fitted to assess the utility of the FBEGS Index as a predictor of bird populations. Results The FBEGS Index was an effective predictor of bird populations in the breeding season, but had limited use in predicting bird populations in winter. Within the overall FBEGS Index, the Associated Features score was a good predictor for populations in both the winter and breeding seasons. In addition, the Boundary Structural score of the field boundary was also an accurate predictor of birds in the breeding season. Conclusion The FBEGS Index has high potential for predicting the effect that changes in the farmed landscape will have on bird populations.426Scopus© Citations 7 - PublicationInteractions between livestock systems and biodiversity in South-East Ireland(Elsevier, 2010-10-15)
; ; ; ; ; Botanical and arthropod surveys at field level, and bird counts within field boundaries were undertaken on the same random sample of 50 grass-based farms in SE Ireland. Additional data relating to farm system, farm-level nutrient inputs, stocking rates, and participation (or otherwise) in the Irish Rural Environment Protection Scheme (REPS) were collated. Generalized linear models (GLM) showed that farm system was a predominant influence explaining observed biological diversity. Both sward plant and arthropod diversity were greater on non-dairy (drystock) farms, but total arthropod abundance was greater on dairy farm swards. Both the breeding bird abundance and species richness were significantly greater in field boundaries on dairy, compared with non-dairy farms. These insights have relevance to the debate regarding the most effective use of public expenditure on agri-environment policy, and suggest that such incentive schemes need to become more clearly customised to realise the conservation potential of different farming systems.1153Scopus© Citations 23 - PublicationFarmland birds and the field boundary evaluation and grading system in Ireland(Faculty of Agriculture, UCD in association with Teagasc, 2005-07)
; ; ; Field boundaries are important habitats for birds within the agricultural landscape. In this study, bird surveys were carried out during the winter and breeding season on nine farms in the east and south-east of Ireland and field boundaries at each site were assessed using the Field Boundary Evaluation and Grading System (FBEGS). Poisson regression demonstrated that FBEGS scores were a good predictor of both winter and breeding bird species richness and diversity within the field boundaries studied. We interpret these preliminary results with caution since our sample size was relatively small (compared to the wide variety of field boundary types found in Ireland) and no single combination of field boundary attributes is likely to be optimum for all bird species. However, our results suggest that FBEGS may be a useful surrogate indicator of overall field boundary bird diversity and we discuss the consequent implications for agri-environmental policy, and for the possible adaptation and use of FBEGS as a tool to monitor the impact of changing farm management practice.1101 - PublicationAntibiotic resistance patterns in Escherichia coli from gulls in nine European countriesBackground: The prevalence of antibiotic resistant faecal indicator bacteria from humans and food production animals has increased over the last decades. In Europe, resistance levels in Escherichia coli from these sources show a south-to-north gradient, with more widespread resistance in the Mediterranean region compared to northern Europe. Recent studies show that resistance levels can be high also in wildlife, but it is unknown to what extent resistance levels in nature conform to the patterns observed in human-associated bacteria. Methods: To test this, we collected 3,158 faecal samples from breeding gulls (Larus sp.) from nine European countries and tested 2,210 randomly isolated E. coli for resistance against 10 antibiotics commonly used in human and veterinary medicine. Results: Overall, 31.5% of the gull E. coli isolates were resistant to ]1 antibiotic, but with considerable variation between countries: highest levels of isolates resistant to ]1 antibiotic were observed in Spain (61.2%) and lowest levels in Denmark (8.3%). For each tested antibiotic, the Iberian countries were either the countries with the highest levels or in the upper range in between-country comparisons, while northern countries generally had a lower proportion of resistant E. coli isolates, thereby resembling the gradient of resistance seen in human and food animal sources. Conclusion: We propose that gulls may serve as a sentinel of environmental levels of antibiotic resistant E. coli to complement studies of human-associated microbiota.
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