Neonicotinoids are the largest group of systemic insecticides worldwide and are most commonly applied as agricultural seed treatments. However, little is known about the extent to which farmland birds are exposed to these compounds during standard agricultural practices. This study uses winter cereal, treated with the neonicotinoid clothianidin, as a test system to examine patterns of exposure in farmland birds during a typical sowing period. The availability of neonicotinoid-treated seed was recorded post-sowing at 39 fields (25 farms), and camera traps were used to monitor seed consumption by wild birds in situ. The concentration of clothianidin in treated seeds and crop seedlings was measured via liquid chromatography-tandem mass spectrometry, and avian blood samples were collected from 11 species of farmland bird from a further six capture sites to quantify the prevalence and level of clothianidin exposure associated with seed treatments. Neonicotinoid-treated seeds were found on the soil surface at all but one of the fields surveyed at an average density of 2.8 seeds/m2. The concentration of clothianidin in seeds varied around the target application rate, whilst crop seedlings contained on average 5.9% of the clothianidin measured in seeds. Exposure was confirmed in 32% of bird species observed in treated fields and 50% of individual birds post-sowing; the median concentration recorded in positive samples was 12 ng/mL. Results here provide clear evidence that a variety of farmland birds are subject to neonicotinoid exposure following normal agricultural sowing of neonicotinoid-treated cereal seed. Furthermore, the widespread availability of seeds at the soil surface was identified as a primary source of exposure. Overall, these data are likely to have global implications for bird species and current agricultural policies where neonicotinoids are in use, and may be pertinent to any future risk assessments for systemic insecticide seed treatments.

The abundance of many seed-eating birds in lowland temperate agricultural landscapes is thought to be limited by the availability of seed-rich habitats that can sustain birds through the winter. Late winter is a period of food shortage for seed-eating farmland birds, when established conservation measures such as sown mixes of seed-bearing plants are often exhausted of seed. Previous work has shown that ryegrass (Lolium) can provide abundant late-winter seed when protected from defoliation from mid-summer. Here we report an experimental study that assessed the utility to seed-eating farmland birds of unharvested cereal crops and seeded ryegrass in a grassland-dominated agricultural landscape that lacked alternative seed-rich habitats. Although both interventions produced abundant autumn seed, cereal plots were depleted by mid-January whereas ryegrass plots retained significant seed and sustained greater bird usage into late winter. Seed yield was higher on Italian L. multiflorum rather than perennial ryegrass L. perenne plots, and on plots that were protected from further defoliation from late May (perennial) or late June (Italian). Despite intervention plots accounting for 60% and 90% of all winter foraging observations of yellowhammer (Emberiza citrinella) and reed bunting (E. schoeniclus) respectively, and yellowhammer body condition being positively related to the proportion of ryegrass in the diet, provision of cereal crops with or without seeded ryegrass had no effect on local population size of either species. Seeded ryegrass constitutes a practical and widely available means of feeding granivorous birds during late winter but filling that 'hungry gap' may not always have the predicted impacts on farmland bird populations.

Lesser Spotted Woodpeckers Dendrocopos minor have dramatically declined and retracted in range in Britain. Pre-breeding foraging may be critical and, although work has been carried out elsewhere in Europe our knowledge of habitat requirements for British birds is limited.We aim to describe foraging behaviour and selection of foraging locations in the pre-breeding period; and to provide descriptions of nest sites and wider habitat selection for nesting.We recorded foraging behaviour, attributes of foraging trees and nest site characteristics and compared them with random areas within woods. Small branches of live oaks at heights usually in the upper third of the tree were most frequently used for foraging. At a wider scale, areas selected contained more deadwood. Nest cavities were usually placed in the upper half of a tree, and oak was commonly used. For nesting, open areas were selected with more dead trees and a mature structure. Many of the attributes important for foraging and nesting have changed in English woodlands in the direction expected to have negative impacts on this species, except for deadwood. Further work shouldmeasure food availability in areas of differing structures. Knowledge of declining species' resource requirements allows targeted and informed management for conservation.

Capsule The breeding success of Lesser Spotted Woodpeckers Dendrocopos minor is now lower in England than previously reported and also lower than found in studies elsewhere in Europe.Aims To quantify the breeding success and identify the causes of nest failure. To test the hypotheses that breeding success is related to aspects of food limitation and parental care, and inclement weather during the nesting period, or to interactions with Great Spotted Woodpeckers.Methods Nests were monitored in three regions of England, recording survival and causes of failure. We measured aspects of food limitation and parental care, rainfall and Great Spotted Woodpecker interactions at nests, to explore whether there was any evidence that these factors were related to breeding success. We compared results to other studies from the UK and continental Europe.Results Nest survival was 52%. The average number of chicks produced from successful nests was 2.8. Chick-stage daily nest survival was positively related to provisioning rates, indicating that food supply may be limiting. The most common cause of nest failure was presumed starvation of chicks after the disappearance of an adult. Some females ceased visiting nests, leaving provisioning solely to the male. This behaviour has been reported elsewhere in Europe, but in the present study males were unable to compensate fully by increasing their provisioning rates, leading to poor nest survival. Provisioning rates and chick-stage daily nest survival were negatively associated with rainfall. Nest predation by Great Spotted Woodpeckers occurred but was a less frequent cause of failure. Aggressive interactions were recorded between the two woodpecker species but these were unrelated to breeding parameters.Conclusions Low breeding success is most probably related to food shortages in the breeding period. Simple population modelling using parameters from the present study and from published work shows that if the low productivity that we have observed is replicated throughout Britain, it would be sufficient to account for the observed population decline. However, the possibility that survival rates are also low cannot be ruled out.

Declines of farmland birds have been pronounced in landscapes dominated by lowland livestock production and densities of seed-eating birds are particularly low in such areas. Modern livestock production often entails a simple cropping system dominated by ley grassland and maize grown for animal feed. These crops often lack invertebrate and seed resources for foraging birds and can be hostile nesting environments. Cereal-based wholecrop silages (CBWCS) offer potential benefits for farmland birds because they can be grown with minimal herbicide applications and can be spring-sown with following winter stubbles. We compared the biodiversity benefits and agronomic yields of winter-sown wheat and spring-sown barley as alternatives to grass and maize silage in intensive dairy livestock systems. Seed-eating birds foraged mainly in CBWCS fields during summer, and mainly on barley stubbles during winter and this reflected the higher densities of seed-bearing plants therein. Maize and grass fields lacked seed-bearing vegetation and were strongly avoided by most seed-eating birds. Production costs of CBWCS are similar to those of maize and lower than those of grass silage. Selective (rather than broad-spectrum) herbicide application on spring barley crops increased forb cover, reduced yields (by 11%) but caused only a small (<4%) increase in production costs. CBWCS grown with selective herbicide and with following winter stubbles offer a practical conservation measure for seed-eating farmland birds in landscapes dominated by intensively-managed grassland and maize. However, the relatively early harvesting of CBWCS could destroy a significant proportion of breeding attempts of late-nesting species like corn bunting (Emberiza calandra) or yellow wagtail (Motocilla flava). Where late-breeding species are likely to nest in CBWCS fields, harvesting should be delayed until most nesting attempts have been completed (e.g. until after 1st August in southern Britain).