A comparison of winter bird communities in agricultural grassland and cereal habitats in Ireland: implications for Common Agricultural Policy reform

McMahon, Barry J.; Carnus, Tim; Whelan, John

doi:10.1080/00063657.2012.758227

Cited by 10 publications

(12 citation statements)

References 41 publications

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“…The disturbance of farmland ecosystems (in conjunction with fragmentation) has adversely affected more specialised farmland species [20]. European agricultural policy plays a vital role in shaping landscape management within these ecosystems [12,21]. There are increasing concerns that EU agricultural policy and a demand for increased food production will put added pressure on farmland biodiversity [22].…”

Section: Reasons For Decline In European Farmland Birdsmentioning

confidence: 99%

Opportunities within the Revised EU Common Agricultural Policy to Address the Decline of Farmland Birds: An Irish Perspective

hUallacháin

Copland²,

Buckley

et al. 2015

Diversity

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Abstract:The loss of global biological diversity continues despite on-going conservation efforts. Agriculture is the major terrestrial land use in Europe and any conservation efforts to protect biological diversity must address sustainable use of these food production systems. Using Ireland, within the European Union policy framework, as an example, the declines in farmland birds are discussed. The opportunities afforded to farmland bird conservation as a result of the recent reform to the Common Agricultural Policy (CAP) are outlined. The potential for revised and refined CAP, specifically agri-environment schemes, to deliver benefits for biodiversity and for farmland bird species within Irish agricultural ecosystems is explored. Despite all the efforts to date and the significant resources invested in implementing agri-environment measures and schemes, few attempts have been made to collect monitoring and surveillance data with which to quantitatively assess the effectiveness of schemes, and measures that are designed to assist in the recovery of farmland biodiversity, including bird species, in Ireland.

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Section: Reasons For Decline In European Farmland Birdsmentioning

confidence: 99%

Opportunities within the Revised EU Common Agricultural Policy to Address the Decline of Farmland Birds: An Irish Perspective

hUallacháin

Copland²,

Buckley

et al. 2015

Diversity

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“…Spatial and temporal scales are a key issue for agrienvironmental schemes (Siriwardena 2010), as well as the management of locally significant habitat types (MacMahon et al 2013). For Corncrakes, spatial and temporal features of grass mowing are crucial: survival of adults, chicks and nests depend on methods and extent of mowing (Green et al 1997a(Green et al , 1997b.…”

Section: Short Reportmentioning

confidence: 99%

The introduction of subsidies for grassland conservation in the Italian Alps coincided with population decline in a threatened grassland species, the CorncrakeCrex crex

Brambilla

Pedrini

2013

Bird Study

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“…Many reasons have been proposed for the existence of overdispersion (Lindén & Mäntyniemi , McMahon et al . 2013a). When explanatory variables are available, it is common simply to quantify their effect on the mean.…”

mentioning

confidence: 99%

“…If so, the data should follow a negative binomial distribution, with the mean–variance relationship governed by an additional parameter that quantifies the flocking or other aggregation behaviour on the response variable (McMahon et al . 2013a).…”

mentioning

confidence: 99%

“…Such data arise when the variance of the counts is larger than the mean, as opposed to the standard Poisson probability distribution, which requires their equality. Many reasons have been proposed for the existence of overdispersion (Lind en & M€ antyniemi 2011, McMahon et al 2013a. When explanatory variables are available, it is common simply to quantify their effect on the mean.…”

mentioning

confidence: 99%

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A novel method for quantifying overdispersion in count data and its application to farmland birds

McMahon

Purvis

Sheridan

et al. 2017

Ibis

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The statistical modelling of count data permeates the discipline of ecology. Such data often exhibit overdispersion compared with a standard Poisson distribution, so that the variance of the counts is greater than that of the mean. Whereas modelling to reveal the effects of explanatory variables on the mean is commonplace, overdispersion is generally regarded as a nuisance parameter to be accounted for and subsequently ignored. Instead, we propose a method that models the overdispersion as a biologically interesting property of a data set and show how novel inference is provided as a result. We adapted the double hierarchical generalized linear model approach to create an easily extendible model structure that quantifies the influence of explanatory variables on the overdispersion of count data, and apply it to farmland birds. These data were from a study within Irish agricultural ecosystems, in which total bird species abundance and the abundance of farmland indicator species were compared on dairy and non‐dairy farms in the winter and breeding seasons. In general, overdispersion in bird counts was greater on dairy farms than on non‐dairy farms, and for total bird numbers, overdispersion was greatest on dairy farms in winter. Our code is fitted using the Bayesian package Rstan, and we make all code and data available in a GitHub repository. Within a Bayesian framework, this approach facilitates a meaningful quantification of the effects of categorical explanatory variables on any response variable with a tendency to overdispersion that has a meaningful biological or ecological explanation.

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A comparison of winter bird communities in agricultural grassland and cereal habitats in Ireland: implications for Common Agricultural Policy reform

Cited by 10 publications

References 41 publications

Opportunities within the Revised EU Common Agricultural Policy to Address the Decline of Farmland Birds: An Irish Perspective

Opportunities within the Revised EU Common Agricultural Policy to Address the Decline of Farmland Birds: An Irish Perspective

The introduction of subsidies for grassland conservation in the Italian Alps coincided with population decline in a threatened grassland species, the CorncrakeCrex crex

A novel method for quantifying overdispersion in count data and its application to farmland birds

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