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Capsule The third survey of breeding waders in Northern Ireland showed large declines in the abundance of Eurasian Curlew, Northern Lapwing and Common Snipe since 1987.Aims To estimate the size of the breeding populations of selected breeding wader species in Northern Ireland in 2013 and population changes since previous surveys in 1987 and 1999.Methods Complete surveys of all potentially suitable breeding habitats were undertaken in randomly selected 2 km squares in each of 146 land-dominated 10 km squares across Northern Ireland. Square selection and a two-visit field method replicated previous surveys conducted in 1987 and 1999.Results Northern Ireland breeding populations of Eurasian Curlew, Northern Lapwing and Common Snipe were estimated to be 526 (±95% CI: 252–783), 860 (277–1545) and 1123 pairs (527–1782), respectively. These estimates represent significant declines in abundance of 82%, 89% and 78% respectively since 1987.Conclusion Breeding populations of Eurasian Curlew, Northern Lapwing and Com...

Capsule Bird and seed abundances decreased in both standard and enhanced Agri-Environment Scheme seed mixtures (plots of seed-bearing crops) between November and February.Aims We analysed effects of Agri-Environment seed mixture type (‘standard’ or ‘enhanced’), plot age and non-target species on seed and bird abundance.Methods Surveys were conducted in November/December and January/February on 36 standard and 19 enhanced seed mixtures to test effect of plot type and age on abundance of buntings, finches and seeds.Results Bunting and finch densities decreased between January/February and November/December. Seed decreased by approximately 70% between surveys, plot type did not affect depletion. Second-year plots contained nearly 90% less seed, and non-significantly lower bunting and finch densities. Bunting densities were positively related to cereal seed abundance, and finch densities to non-cereal seed; these relationships did not differ between plot types. There was no evidence that non-target species af...

Capsule Bunting densities decreased in winter wheat stubbles between November/December and January/February, but not in spring barley stubbles.Aims We investigated bird use and vegetation in relation to Agri-Environment Scheme over-winter stubble type and preceding crop.Methods We surveyed 15–17 fields each of: ‘standard’ Agri-Environment Scheme stubble on Entry Level Stewardship farms (EF6); ‘standard’ Agri-Environment Scheme stubble on Higher Level Stewardship farms (HF6); stubble preceded by low-input cereal (HF15); extended over-winter stubble (EF22) and non-Agri-Environment Scheme stubble in November/December 2011 and January/February 2012. Stubbles were preceded by spring barley or winter wheat crops.Results Previous cropping and time of year were the main factors influencing bird densities: bunting densities declined in winter wheat stubbles between surveys, but not in spring barley stubbles.Conclusion The main factor limiting the ability of over-winter stubbles to reverse national population trend...

Capsule Mealworm provisioning increased clutch size and chick survival in garden-nesting House Sparrows.Aim We tested experimentally whether invertebrate availability limits reproductive success in garden-nesting House Sparrows Passer domesticus.Methods Mealworms were provided in feeders as supplementary food for House Sparrows nesting in suburban and rural domestic gardens. Surveys of provisioning adult sparrows were used to determine mealworm usage and nest outcomes were monitored.Results Provisioning parent sparrows travelled up to 165 m from nests to collect mealworms, but most usage of supplementary food was confined to nests within 30 m of feeders. Mealworm provisioning increased clutch size and chick survival which together increased fledgling production by 55%.Conclusions Management interventions that increase the availability of invertebrate prey for garden-nesting House Sparrows have the potential to stimulate substantial increases in reproductive success.

Capsule Empirical support is provided for the design and field methods associated with a replicated supplementary feeding experiment. Aims We tested assumptions associated with a supplementary feeding experiment in which counts of House Sparrows were used to infer impacts of feeding mealworms and seed on reproductive output and population size. Methods Supplementary food was provided at 33 House Sparrow colonies spread across suburban London, with 33 unfed colonies serving as controls. We compared the characteristics of fed and unfed colonies and tested whether competition for mealworms increased with colony size. We tested whether counts of young sparrows reflected variation in reproductive output and whether supplementary feeding affected the distribution of young sparrows. Results Fed and unfed colonies were similar with respect to habitat, cat density, background feeding and initial colony size. Intensity of feeder usage increased with colony size. Counts of fledglings and juveniles were positively co...

Capsule Yellow Wagtails successfully raised two consecutive broods in landscapes dominated by autumn-sown crops and did not require spring crops or fallow plots for later nesting. Aims To assess whether arable landscapes dominated by winter cropping provide habitats that allow Yellow Wagtails to raise two successful broods. To assess the utility of spring cultivated agri-environment fallow plots as a nesting and foraging habitat for Yellow Wagtails. Methods Nesting success and foraging behaviour of Yellow Wagtails was monitored on lowland arable farmland dominated by winter cropping during two successive breeding seasons. Results Yellow Wagtails successfully raised first and second broods mainly in winter cereals, with later nests being more successful. Some nests were initiated in bean fields where egg-stage failure rates were high, probably as a consequence of depredation. Fallow plots were not used for nesting but, along with other areas of sparse vegetation, were regularly used for foraging. Conclusio...

Capsule Despite negative effects of inorganic fertilizer on weeds and invertebrates in cereal fields, impacts on bird usage were weak and non-linear. Aim To assess the effects of inorganic fertilizer application to winter cereals on breeding-season usage by farmland birds. Methods We measured bird usage of winter-sown cereal fields across a gradient of inorganic fertilizer inputs and tested for influences of management intensity and availability of semi-natural habitat on species richness and abundance of farmland birds. Results Avian species richness and bird abundance were unrelated to fertilizer inputs, and declined at higher levels of total vegetation cover. Sky Lark abundance increased, while Yellow Wagtail counts declined with the extent of semi-natural habitat. Sky Lark abundance increased with vegetation cover and peaked at an intermediate level of weed species richness. Yellow Wagtail counts peaked at intermediate levels of fertilizer inputs. Conclusions Compared with much of western Europe, cereal production in central Hungary is characterized by modest fertilizer inputs and large areas of semi-natural habitat. There was little evidence that increased applications of fertilizer are likely to have negative impacts on farmland birds, although increased application might reduce habitat suitability for Yellow Wagtails. Loss of semi-natural habitat is likely to have negative impacts on Sky Larks.

Capsule Oilseed Rape was the preferred breeding season habitat for Reed Buntings on arable farmland and reduced this species' dependence on wet features. Aims To identify preferred breeding season habitats for Reed Buntings on arable farmland and factors influencing the attractiveness of Oilseed Rape. Methods Summer usage of arable fields by nesting and foraging farmland birds was assessed from a random sample of arable fields in Nottinghamshire, England. Generalized linear models were used to identify habitat and landscape predictors of Reed Bunting breeding density and of foraging by other farmland birds. Results Occupancy rates and densities of Reed Buntings were approximately four times greater in Oilseed Rape fields than in cereals or set-aside. Reed Buntings commonly nested in Oilseed Rape fields more than 100 m from wet features, but the same was not true of cereals or set-aside fields. Usage of Oilseed Rape by farmland birds was promoted by weediness, bare patches and nearby wet features, and redu...

Capsule There are regional and habitat differences, but no long-term decline in numbers. Aims To review the evidence for declining Swallow populations in Britain, based on the British Trust for Ornithology's long-running Common Birds Census (CBC) and suggest possible causes. Methods Trends were fitted to CBC data for 1964–98 using a generalized linear modelling framework and analysed with regard to specific regions and habitats. Current habitat use, particularly of different farming types, was characterized using data from the Breeding Bird Survey. Correlations between Swallow population size and loss of nest-sites and rainfall in the non-breeding grounds were examined. Results Although Swallow numbers show large annual fluctuations, there is no evidence for a long-term decline on CBC plots. Numbers seem to have declined on farms in eastern England and in non-farmland habitats, but were not correlated with changes in cattle numbers or with an index of regional changes in nest-site availability. The number...

We present a method for studying post-fledging survival rates from data on national ringing recoveries. The approach extends the classical two-age-class models of Brownie et al. (1985) to include a third age-class of birds ringed as nestlings. The models can incorporate age-class-specific and year-specific variation in reporting rates and survival rates. Unlike intensive resighting studies at single sites, this approach does not confound death with emigration and provides estimates of survival which are representative of a larger geographical area. We implemented the models with SURVIV software, using likelihood-ratio tests to assess the significance of possible age and year effects art survival rates or reporting rates. We demonstrate this approach using a set of data an British-ringed Song Thrushes Turdus philomelos. In this case, we were unable to detect any age-class-specific or year-specific variation in reporting rates and, although the survival rates of first-year and adult Song Thrushes varied significantly between years, post-fledgling survival did not show any detectable inter- annual variation. Song Thrushes ringed as nestlings had a 0.38 chance (95% CI = 0.30-0.45) of surviving the 63-day post- fledging period (here defined as the period separating the average dates of birds ringed as nestlings and birds ringed as independent first-year birds). [KEYWORDS: Population]

Ring recovery data were used to assess changes in the survival rates of Cormorants in Britain and Ireland between 1965 and 1994. It was found that 99% were ringed as nestlings, thus necessitating an assumption of constant reporting rate across age-classes. The wide geographical spread of ringing effort since 1965 produced sufficient recoveries to enable analyses of trends in survival and reporting rates, but regional subdivisions of the data resulted in high sampling correlations between survival estimates. The assumption of a constant reporting rate across age-classes may be violated for British and Irish Cormorants, because first-year birds are more likely to be shot or caught in fishing nets than older birds and they have a differing seasonal pattern of recoveries. A simple simulation showed that first-year, but not adult, survival estimates were particularly sensitive to age-specific variation in reporting rates. However, the observed trend in first-year survival appeared robust to the assumption of c...

The Constant Effort Sites (CES) Ringing Scheme of the British Trust for Ornithology aims to provide annual measures of change in the abundance and productivity of common breeding passerines in scrub and wetland habitats in Britain and Ireland. Changes in the sizes of the annual catches, from a set of standard mist nets operated during 12 summer (May–August) visits, are combined across sites to produce estimates of the percentage change in adult and juvenile numbers. The proportion of juveniles in the catch is used as a relative measure of breeding productivity. Methods are presented for calculating standard errors of between-year changes in both adult and juvenile catches, and changes in the proportion of juveniles. Present levels of precision are summarized and predictions are made concerning likely improvements in precision from a larger CES Scheme. For most of the species considered there was little evidence that between-year changes in catches of adults at CE sites have differed between habitats, regi...

Capsule The annual survival rate of adult female Goldeneye in Scotland was 83.9% (se = ±4.1%).