The registration of pesticides follows guidance published by the European Food Safety Authority (EFSA). As a default, the EFSA guidance document on risk assessment for birds and mammals assumes that animals feed exclusively on pesticide-treated fields. However, the guidance document suggests refining the risk via the proportion of food animals obtain from a treated field or specific crop (expressed via the portion of diet obtained from a treated area [PT value]). The EFSA guidance equalizes the portion of food taken from a treated area per day with the portion of time spent potentially foraging over the course of a day within this area. Therefore, radiotracking is commonly used to gather species-, crop-, and season-specific PT data, and radio telemetry of continuously tracked farmland species can deliver individual PT values for a given day, crop, and species. In the present study the authors introduce a way of calculating long-term PT values based on empirically recorded data via telemetry field studies for the most appropriate use in wildlife risk assessment of pesticides. The novel aspect of the proposal is that the authors follow the prerequisite given by EFSA to cover the long-term risk by introducing 21-d PT values that aim to cover both intra- and inter-individual variability of foraging focal farmland species in cropped habitats. Currently, the intra-individual variability is not taken into account for PT calculations. The authors demonstrate this approach and discuss EFSA guidance input requirements for PT values recorded in field studies, based on a PT field study conducted with woodpigeons (Columba palumbus) radiotracked in an agricultural landscape in the United Kingdom. The results indicate that a 21-d PT value considering intra-individual variability gives a more appropriate PT value for long-term risk assessments. Environ Toxicol Chem 2017;36:1270-1277. © 2016 SETAC.

Increasing agricultural intensification has put farmland bird populations under great stress. Although organically managed farms tend to have higher densities of farmland birds than conventionally managed holdings, differences in crop management may also lead to differences in breeding success. With the use of agrochemicals prohibited on organic farms, weeds are controlled using mechanical methods that may pose a threat to ground‐nesting birds. This study compares the territory densities and nesting success of the Lapwing Vanellus vanellus on organic and conventional arable farms in the Netherlands. Territory densities were generally higher on organic farms, although in one year nesting success was lower on organic than on conventional farms. This was caused by higher nest loss resulting from farming activities on organic farms. There were no differences in predation rates. The results of this study show that breeding Lapwings may face potential threats on organic farms. To sustain or enhance Lapwing populations on these farms, additional conservation measures should be implemented.

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SummaryAs a result of agricultural intensification, populations of farmland birds have been in steep decline for several decades. Reduction in food abundance has been mentioned as one factor behind these declines. Extensive farm management, such as use of organic methods, is expected to provide more food for birds. In this study we compared invertebrate prey abundance for birds during the breeding season between organic and conventional arable farms. We made comparisons for three different groups of birds: (1) birds feeding on soil-living invertebrates (earthworms), (2) birds feeding on ground-dwelling invertebrates and (3) birds feeding on aerial invertebrates. Invertebrate abundance was compared between organic and conventional farms, crop and non-crop habitats, and between crop and non-crop habitats under the same farm management. On organic sites, earthworm abundance was 2-4 times higher than on conventional sites, but no differences were found between crop types. Total abundance of ground-dwelling invertebrates did not differ between organic and conventional sites, but positive effects were found for several individual taxonomic groups, such as carabid beetles and spiders. On organic farms, invertebrate abundance was higher in carrots, cereals and onions compared to other crops; on conventional farms this was true for onions. When compared with most crops, ground-dwelling invertebrate abundance was low in uncropped field margins and on ditch banks. On organic farms, aerial invertebrate abundance was approximately 70% higher than on conventional farms. On cereal fields, aerial invertebrates were especially abundant.