Corn Bunting Miliaria Calandra Research Articles

Energy crops affecting farmland birds in Central Europe: insights from a miscanthus-dominated landscape

The expansion of energy crops such as miscanthus Miscanthus x giganteus has changed the habitat of European farmland birds. However, most studies on the subject are based in Western Europe. We surveyed the avian community in a sample bioenergy landscape in Poland to investigate the pattern of use of the crop by birds in Central Europe. During a year-long survey, 80 species were noted, with 32 sighted in miscanthus. The number of bird sightings was negatively correlated with the area covered by miscanthus in study plots. In contrast to results from Western Europe, most woodland-generalist bird species tended to avoid miscanthus. Farmland species (e.g. the corn bunting Miliaria calandra; the tree sparrow Passer montanus; the starling Sturnus vulgaris; the yellowhammer Emberiza citrinella) were less frequently sighted in the crop than in other habitats. Only a few species were sighted more often in miscanthus than in other habitats, e.g. the marsh warbler Acrocephalus palustris; the reed bunting Emberiza schoeniclus; the whinchat Saxicola rubetra. The potential impact of expanded miscanthus cropping on bird communities in Central and Eastern Europe may diverge from predictions derived from studies based in Western Europe due to differing habitat preferences and bird densities between the regions. For a majority of farmland species, the crop may constitute only a suboptimal, supplementary habitat, with only a few birds potentially adapting to the exploitation of bioenergy plantations.

СОВРЕМЕННОЕ РАСПРОСТРАНЕНИЕ И ОЦЕНКА ОБИЛИЯ СТЕПНОГО ЖАВОРОНКА (MELANOCORYPHA CALANDRA) И ПРОСЯНКИ (MILIARIA CALANDRA) (PASSERIFORMES, AVES) НА СЕВЕРЕ НИЖНЕГО ПОВОЛЖЬЯ И СОПРЕДЕЛЬНЫХ ТЕРРИТОРИЯХ

СОВРЕМЕННОЕ РАСПРОСТРАНЕНИЕ И ОЦЕНКА ОБИЛИЯ СТЕПНОГО ЖАВОРОНКА (MELANOCORYPHA CALANDRA) И ПРОСЯНКИ (MILIARIA CALANDRA) (PASSERIFORMES, AVES) НА СЕВЕРЕ НИЖНЕГО ПОВОЛЖЬЯ И СОПРЕДЕЛЬНЫХ ТЕРРИТОРИЯХ

Integrating Open Access Geospatial Data to Map the Habitat Suitability of the Declining Corn Bunting (Miliaria calandra)

The efficacy of integrating open access geospatial data to produce habitat suitability maps for the corn bunting (Miliaria calandra) was investigated. Landsat Enhanced Thematic Mapper Plus (ETM+), Shuttle Radar Topography Mission (SRTM) and Corine (Coordination of Information on the Environment) land cover data for the year 2000 (CLC2000) were processed to extract explanatory variables and divided into three sets; Satellite (ETM+, SRTM), CLC2000 and Combined (CLC2000 + Satellite). Presence-absence data for M. calandra, collected during structured surveys for the Catalan Breeding Bird Atlas, were provided by the Catalan Ornithological Institute. The dataset was partitioned into an equal number of presence and absence points by dividing it into five groups, each composed of 88 randomly selected presence points to match the number of absences. A logistic regression model was then built for each group. Models were evaluated using area under the curve (AUC) of the receiver operating characteristic (ROC). Results of the five groups were averaged to produce mean Satellite, CLC2000 and Combined models. The mean AUC values were 0.69, 0.81 and 0.90 for the CLC2000, Satellite and the Combined model, respectively. The probability of M. calandra presence had the strongest positive correlation with land surface temperature, modified soil adjusted vegetation index, coefficient of variation for ETM+ band 5 and the fraction of non-irrigated arable land.

How to improve agri-environment schemes to achieve meadow bird conservation in Europe? A case study in the Saône valley, France

Ongoing meadow bird demographic trends in Europe raise the question of the effectiveness of public policy aiming to halt biodiversity loss. In this study, we attempted to understand the success and failures in one of the first French Agri-Environment Schemes (AES), 20 years after its implementation. After annually postponing grass harvesting to 1 or 15 July in 25 % of a 3,000-ha lowland meadow system, we observed a clear demographic increase in the Eurasian Curlew Numenius arquata, the Whinchat Saxicola rubetra and the Yellow Wagtail Motacilla flava. No positive effects were recorded for the Skylark Alauda arvensis, the Corn Bunting Miliaria calandra and the Reed Bunting Emberiza schoeniclus, possibly as a result of increased competition with Whinchats and Yellow Wagtails, and the Corncrake Crex crex declined sharply despite the implemented measures. The successful results were attributed, for the Curlew to the species’ early nesting and high adult survival, for the Whinchat to the probable support of immigration, and for the Yellow Wagtail to a possible capacity to avoid unfavourable nesting situations. Late breeding and low adult survival may contribute to explain the continuing Corncrake decline. In the study site, late mown AES areas were too small and fragmented to match efficiently the territory aggregations. We recommend to extend AES principles to all the European range of targeted species, even outside the EU, and to develop species-specific spatial strategies.

Measuring the functional responses of farmland birds: an example for a declining seed‐feeding bunting

1. Many farmland bird species have undergone significant declines. It is important to predict the effect of agricultural change on these birds and their response to conservation measures. This requirement could be met by mechanistic models that predict population size from the optimal foraging behaviour and fates of individuals within populations. A key component of these models is the functional response, the relationship between food and competitor density and feeding rate. 2. This paper describes a method for measuring functional responses of farmland birds, and applies this method to a declining farmland bird, the corn bunting Miliaria calandra L. We derive five alternative models to predict the functional responses of farmland birds and parameterize these for corn bunting. We also assess the minimum sample sizes required to predict accurately the functional response. 3. We show that the functional response of corn bunting can be predicted accurately from a few behavioural parameters (searching rate, handling time, vigilance time) that are straightforward to measure in the field. These parameters can be measured more quickly than the alternative of measuring the functional response directly. 4. While corn bunting violated some of the assumptions of Holling's disk equation (model 1 in our study), it still provided the most accurate fit to the observed feeding rates while remaining the most statistically simple model tested. Our other models may be more applicable to other species, or corn bunting feeding in other locations. 5. Although further tests are required, our study shows how functional responses can be predicted, simplifying the development of mechanistic models of farmland bird populations.

COEVOLUTIONARY INTERACTIONS BETWEEN COMMON CUCKOOS AND CORN BUNTINGS

Abstract Although Old World buntings (Emberizinae) may be considered suitable Common Cuckoo (Cuculus canorus) hosts, there is at present no evidence that any of the European species are regularly parasitized. Most historical parasitism records refer to the Yellowhammer (Emberiza citrinella) and Reed Bunting (E. schoeniclus). Both of these species reject almost 100% of experimentally added nonmimetic eggs, and also a considerable proportion of experimentally added conspecific eggs, showing exquisite egg discrimination abilities. In this paper, we report Common Cuckoo parasitism and egg rejection behavior in a Bulgarian population of another Old World Emberizinae, the Corn Bunting (Miliaria calandra). We found this species was regularly parasitized (9%, 8 of 90 nests) and that the parasitism rate was consistent among the three years of our study. Naturally laid Common Cuckoo eggs were fairly good mimics of host eggs and most were accepted (5 of 7). The Corn Bunting proved to be a suitable Common Cuckoo host...

Microhabitat use and social structure in Linnet Carduelis cannabina and Corn Bunting Miliaria calandra at a winter roost in central Spain

Capsule Both species selected particular patches for roosting, and Linnets but not Corn Buntings showed a social structure with males occupying the preferred roosting positions. Aims To evaluate microhabitat preferences of Linnet and Corn Bunting within a winter communal roost, and to examine roost structure according to sex, age and body size. Methods We captured Linnets and Corn Buntings along a habitat gradient in a reed-bed in central Spain when they were coming to roost. Each bird was sexed, aged, and several body traits were measured. We also characterized the habitat patches where the birds were trapped and grouped patches according to their similarity. Results Three groups of patches were defined according to reed structure. Linnets preferred patches with low density of high and thick shoots, while Corn Buntings preferably used patches with intermediate values for these variables. Interspecific competition for preferred positions was not evident. Male Linnets were proportionately more abundant in the preferred patches, and individuals in lower body condition, independent of sex, age or body size, occupied the non-preferred patches. Male Corn Buntings were less abundant, bigger in size, and showed better condition than females, although differences in body size and condition were not apparent among patches within the roost. Conclusion Our results suggest that among-patch differences in structure and location within a reed-bed generate microhabitats that differ in quality for roosting passerines. This habitat heterogeneity in turn seems to be responsible for the social spatial structure observed in Linnets, in which females and individuals in poor physiological condition were displaced, possibly through competition, towards non-preferred positions. The relatively small body size of Linnets compared to Corn Buntings might explain Linnets' preference for patches that seem to provide more protection against harsh weather conditions.

Evaluating the Breeding Bird Survey for producing national population size and density estimates

Capsule The BBS has potential for producing better estimates of habitat-specific densities and population sizes for many UK bird populations than those available previously. Aims To examine the use of the Breeding Bird Survey (BBS) in providing unbiased national population and habitat-specific density estimates of British birds. Methods Line transect data collected by volunteers in 1998 from 2287 1-km squares across the UK were analysed using distance sampling methods to calculate habitat-specific density and abundance estimates. For each species, the habitat-specific decline in detectability with distance from a transect line was modelled and applied at a regional level to incorporate variation in sampling intensity in different areas of the country. Results National population and density estimates calculated here were at a magnitude expected for at least seven species in this study. However, national population size estimates were higher than expected for Starling Sturnus vulgaris, House Sparrow Passer domesticus, Blackbird Turdus merula, Greenfinch Carduelis chloris, Jackdaw Corvus monedula, Whitethroat Sylvia communis, Woodpigeon Columba palumbus and Linnet Carduelis cannabina and lower than expected for Skylark Alauda arvensis, Dunnock Prunella modularis, Song Thrush Turdus philomelos and Corn Bunting Miliaria calandra. These differences are likely to be related to differences in sampling design and survey methods. For example, Starling, House Sparrow, Blackbird, Jackdaw, Greenfinch and Wood Pigeon, which have considerable populations in urban areas, were undoubtedly underestimated by the Common Birds Census (CBC). The counts of species that flock during the breeding season, or are not strongly territorial (e.g. Linnet, Jackdaw and Wood Pigeon) could be biased if detectability is strongly related to flock size. National population estimates of Skylark and Corn Bunting are lower than those based on CBC, but higher, or similar, to targeted national surveys of these species. Possible reasons for the differences between these estimates are considered. Conclusions This study highlights the strength of the BBS over previous data sources in producing national estimates of density and abundance at the habitat and national level. More research on the sex ratio and status of birds counted during surveys, and on the reliability of the detectability functions derived from distance sampling is needed to improve the interpretation of population estimates derived from BBS data.

Exploring the effects of land abandonment on habitat structures and on habitat suitability for three passerine species in a highland area of Central Italy

This study addresses the effects of land abandonment on landscape structure and on the habitat suitability for three passerine species (red-backed shrike Lanius collurio, corn bunting Miliaria calandra and yellowhammer Emberiza citrinella) in a span of 40 years (from 1954 to 1994) in an Appenninic rural area. Aerial photographs were used to compare changes in variables related to landscape structure. Multivariate logistic regression was used to model species–habitat relations. The most important landscape changes highlighted by the present study were an expansion of woodland and scrubland at the expense of complex field mosaics, which were abandoned, and an overall decrease of vertical elements and structural diversity in the areas still being farmed. These highly significant changes affected also the correlations between variables. All of the three bird species showed an association to landscape features which were subject to significant change, such as hedgerows, untilled land, bushes and trees. The long-term effects of land abandonment are likely to be a loss of habitat for farmland birds. Some environmental and socio-economic factors related to land abandonment are also discussed.

Evidence for the indirect effects of pesticides on farmland birds

Indirect effects of pesticides, operating through the food chain, have been proposed as a possible causal factor in the decline of farmland bird species. To demonstrate such a link, evidence is needed of (1) an effect of food abundance on breeding performance or survival; (2) an effect of breeding performance or survival on population change; and (3) pesticide effects on food resources, sufficient to reduce breeding performance or survival, and hence to affect the rate of population change. Evidence under all three categories is only available for one species, the Grey PartridgePerdix perdix, although data showing effects of pesticides on food resources and relationships between food resources and breeding performance are also available for some other species. This paper reports on recent work investigating the effects of pesticides on YellowhammerEmberiza citrinellaand SkylarkAlauda arvensisduring the breeding season. The probability of brood reduction in Yellowhammer was affected by the proportion of the foraging area around the nest which was sprayed with insecticide. No significant effects of pesticides were recorded on Skylark chick condition or growth rate, but sample sizes were small. Invertebrate food abundance affected chick condition (Skylark) and the number of chicks fledging (Yellowhammer and Corn BuntingMiliaria calandra; relationship for the latter derived from re‐analysis of data from an earlier study). Other recent work is briefly reviewed and the current evidence for the indirect effects of pesticides is summarized. Significant knowledge gaps are identified and some of the issues involved in resolving these are discussed.

Effects of habitat on the use of supplementary food by farmland birds in winter

Providing supplementary food for seed‐eating birds in winter is likely to be a key strategy, in some form, in future efforts to conserve farmland biodiversity. We present interim analyses of data on the bird use of artificial feeding sites under the RSPB‐led BirdAid project and the BTO‐led Winter Food for Birds (WFFB) project, investigating the influence of the habitat context at the local and landscape scales on the use of supplementary food by Yellowhammer Emberiza citrinella, Corn Bunting Miliaria calandra, Tree Sparrow Passer montanus, House Sparrow Passer domesticus, Chaffinch, Fringilla coelebs, Greenfinch Carduelis chloris, Goldfinch C. carduelis and Reed Bunting Emberiza schoeniclus. Our results reveal species‐specificity, rather than general patterns, in relationships between habitat variables and counts. The responses of the only species for which both BirdAid and WFFB provided data, the Yellowhammer, differed between the projects, suggesting that the results were not geographically general. The results fail to indicate justifiable firm habitat prescriptions for site locations that would suit a number of species. Clearer patterns were apparent in results with respect to areas of major habitats in the landscapes surrounding feeding sites, which suggested that local abundance could have an important effect on the use of supplementary food. Future analyses of data from these projects will attempt to separate the competing probable habitat influences on local bird abundance and alternative resource availability.

Rule-based predictive models are not cost-effective alternatives to bird monitoring on farmland

Monitoring bird populations is labour-intensive and requires expert knowledge. Development of more cost-effective methods of bird species monitoring is therefore desirable. Simple rule-based (RB) models were developed that predicted the presence of birds in lowland arable farmland in the breeding season. These were based on the presence of key habitat elements required by the birds identified from the literature. Habitat data and bird data were collected independently from 525 transects each of which ran along a field margin. Model performance was tested in five species: grey partridge Perdix perdix, skylark Alauda arvensis, linnet Carduelis cannabina, corn bunting Miliaria calandra and yellowhammer Emberiza citrinella. RB models were not good predictors of species presence. Model performance did not vary appreciably between early or late breeding season or according to geographic region. Skylark had the best performing model, but even in this case the predictive power was low. Prediction of species presence from habitat survey data is therefore unlikely to be a cost-effective method of monitoring birds on British farmland.

The selection of stubble fields by wintering granivorous birds reflects vegetation cover and food abundance

Summary Fields left fallow after harvest (i.e. stubble fields) support high wintering densities of many species of granivorous bird. We examined correlates of use by eight such species of different types of intensively managed wheat and barley stubble fields, organic wheat fields and set‐aside fields on mixed lowland farmland in central England. Field occupancy was studied in relation to the physical characteristics of fields and seed abundance. Higher seed abundance was associated with greater occupancy by linnet Carduelis cannabina, grey partridge Perdix perdix, chaffinch Fringilla coelebs, yellowhammer Emberiza citrinella, reed bunting Emberiza schoeniclus and corn bunting Miliaria calandra. Larger areas of bare earth within stubble fields were associated with greater occupancy by linnet, yellowhammer, reed bunting and corn bunting, but lower occupancy by woodpigeon Columba palumbus. On conventional intensively farmed sites, seed abundance and area of bare earth were significantly greater on barley stubbles than on wheat stubbles. Seed numbers fell throughout the winter in all stubble types, although reductions were greatest on intensive barley stubbles, intermediate on intensive wheat stubble and lowest on undersown organic wheat stubbles. Within fields occupied by linnets, areas used for feeding had significantly greater quantities of seeds known to be important in their diet. Feeding areas also had a greater area of bare earth than randomly selected ‘non‐feeding areas’. Linnets and reed buntings were rarely found on fields where densities of weed seeds important in their diets fell below 250 seeds m−2. In autumn, yellowhammers and grey partridges rarely fed on fields where cereal grain density was below 50 m−2. However, in spring, both species fed on these fields irrespective of grain density, perhaps indicating a switch to other food sources. We suggest that land managers wishing to maximize the value of overwinter stubble fields for granivorous birds locate such fields where there is a substantial natural regeneration of weed flora and where previous cropping (e.g. barley) is likely to offer a sparse stubble with substantial areas of bare ground.

Contrasting patterns of change in the distribution and abundance of farmland birds in relation to farming system in lowland Britain

AbstractPatterns of change in distribution (presence/absence) and abundance since the late 1960s were examined in 20 species of farmland bird in southern Britain in predominantly arable (eastern), predominantly mixed (central) and predominantly grassland (western) regions. Comparisons were made between changes in distribution and in abundance to determine whether these measures show similar relationships to environmental change. Local extinctions of selected species and reductions in species richness were significantly greater in the predominantly grassland region. Decreases in abundance were greatest in seven species in the predominantly arable region, two in the mixed region and nine in the grassland region. Changes in distribution and abundance showed consistent patterns in three species, turtle dove Streptopelia turtur L., yellow wagtail Motacilla flava L. and reed bunting Emberiza schoeniclus L. In another four species, grey partridge Perdix perdix L., lapwing Vanellus vanellus L., tree sparrow Passer montanus L. and corn bunting Miliaria calandra L., decreases in abundance were greatest in the arable region, yet declines in distribution were lowest. For other individual species, changes in distribution were too small to draw any conclusions in relation to farm type. We suggest that modern grassland systems are suboptimal habitats compared to arable or mixed agricultural land for many farmland species that occur at relatively low density in the more western, grass‐dominated region. Declines in abundance are therefore more likely to lead to local extinction in these areas than in eastern areas where abundance is higher. However, the role of changes in grassland management on bird populations requires further research. It is suggested that conclusions drawn from changes in distribution alone, in the absence of supporting data on changes in abundance, may be misleading where the aim is to assess how large‐scale spatial dynamics of populations relate to environmental change.

The phylogenetic status of the Corn Bunting Miliaria calandra based on mitochondrial control‐region DNA sequences

IbisVolume 143, Issue 2 p. 299-303 The phylogenetic status of the Corn Bunting Miliaria calandra based on mitochondrial control-region DNA sequences PATRICIA LM. LEE, Corresponding Author PATRICIA LM. LEE Edward Grey Institute of Field Ornithology, Department of Zoology, South Parks Road, Oxford OX1 3PS, UK*School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea SA2 BPP, UK. Emai1: P.L.M.Lee@swansea.ac.ukSearch for more papers by this authorLYNNE J. RICHARDSON, LYNNE J. RICHARDSON Edward Grey Institute of Field Ornithology, Department of Zoology, South Parks Road, Oxford OX1 3PS, UKSearch for more papers by this authorRICHARD B. BRADBURY, RICHARD B. BRADBURY Edward Grey Institute of Field Ornithology, Department of Zoology, South Parks Road, Oxford OX1 3PS, UKSearch for more papers by this author PATRICIA LM. LEE, Corresponding Author PATRICIA LM. LEE Edward Grey Institute of Field Ornithology, Department of Zoology, South Parks Road, Oxford OX1 3PS, UK*School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea SA2 BPP, UK. Emai1: P.L.M.Lee@swansea.ac.ukSearch for more papers by this authorLYNNE J. RICHARDSON, LYNNE J. RICHARDSON Edward Grey Institute of Field Ornithology, Department of Zoology, South Parks Road, Oxford OX1 3PS, UKSearch for more papers by this authorRICHARD B. BRADBURY, RICHARD B. BRADBURY Edward Grey Institute of Field Ornithology, Department of Zoology, South Parks Road, Oxford OX1 3PS, UKSearch for more papers by this author First published: 28 June 2008 https://doi.org/10.1111/j.1474-919X.2001.tb04487.xCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume143, Issue2April 2001Pages 299-303 RelatedInformation

Corn Bunting Miliaria calandra populations, landscape and land-use in an arable district of eastern England

A study of Corn Buntings Miliaria calandra, a rapidly declining red-listed species in the United Kingdom, was conducted over five years in the intensively cultivated, arable landscape of north-east Essex, eastern England. Mean densities in study plots ranged from 8 to 15 territories per km2, with evidence of a decline over the five years. A total of 278 singing males was located in 247 km2 of farmland, some 2–3% of the U.K. population and therefore of national significance. The distribution of territories was highly clumped and there was marked territory fidelity between years. There was a strong preference for territories encompassing field boundaries without hedges and a general avoidance of hedges. Territories occupied in four or five years were more likely to contain water-filled ditches and/or weedy farm tracks than territories occupied in a single year. Song posts may be important resources. There was little preference shown for particular crops or other land-uses during the breeding season. During the winter period there was a strong selection for feeding on the small amount of grass, and in the late winter period, on stubbles. Lack of feeding opportunities in winter would appear to be critical to Corn Buntings. It is suggested that a retention of stubbles over winter on the 26% of farmland destined for spring sowing could be highly beneficial to Corn Bunting populations and that this could be initially targeted at those areas currently holding dense breeding populations.

Agricultural habitat-type and the breeding performance of granivorous farmland birds in Britain

Conservation concern about granivorous birds has led to the implication of changing agricultural practices as causes of widespread population decline. We investigate relationships between breeding performance and the agricultural environment for ten granivorous farmland bird species (Stock Dove Columba oenas, Skylark Alauda arvensis, Tree Sparrow Passer montanus, Chaffinch Fringilla coelebs, Greenfinch Carduelis chloris, Linnet C. cannabina, Bullfinch Pyrrhula pyrrhula, Reed Bunting Emberiza schoeniclus, Yellowhammer E. citrinella and Corn Bunting Miliaria calandra). We analyse long-term, extensive data from the British Trust for Ornithology's Nest Record Scheme on breeding performance per breeding attempt with respect to farmland type (arable, grazing or mixed) and time (pre- and post-1975–76). The influence of habitat is investigated at two different scales: within the nesting territory and at the landscape level. Relationships between farmland type and (temporal changes in) breeding performance tended to be species-specific, but a few patterns were each common to some species. Improvements in breeding performance occurred across all three farmland types for four declining species. Grazing farmland seems to have deteriorated as breeding habitat for Linnet and arable/mixed farmland for Reed Bunting. Mixed farming at the territory scale supported better breeding performance for four species, three of which (Bullfinch, Yellowhammer and Corn Bunting) have declined concurrently with mixed farming. Pastoral landscapes supported better breeding performance for up to seven species, six of which have undergone large declines. Arable landscapes supported better breeding only for the stable or increasing Chaffinch and Greenfinch. Different relationships between farming regime and breeding performance were found at the two scales considered.

The importance of variation in the breeding performance of seed‐eating birds in determining their population trends on farmland

Summary 1. Changes in agriculture have been linked to widespread declines in farmland bird populations. One approach to the identification of the causes of observed population changes is to investigate historical changes in national demographic rates. 2. We analysed the British Trust for Ornithology’s nest records database to investigate whether long‐term farmland population trends could have been driven by changes in several components of the annual breeding performance of 12 granivorous bird species. Clutch size, brood size, chick : egg ratio and daily nest failure rates were analysed with respect to blocks of years during which abundance (as measured by the Common Birds Census) was increasing, stable or declining. The individual components of breeding performance were combined to provide estimates of the production of fledglings per breeding attempt. 3. Most species’ population declines were not associated with poor breeding performance per attempt. Effects of environmental change on this parameter therefore cannot be a general mechanism behind the major population declines seen. 4. A fall in linnet Carduelis cannabina fledgling production per attempt, driven primarily by increased nest failure rates during the egg period, represented the strongest evidence for an important effect of breeding performance on abundance. This change could have driven the principal population decline (1975–86) for this species. 5. Conversely, at least for the declining turtle dove Streptopelia turtur, skylark Alauda arvensis, tree sparrow Passer montanus, yellowhammer Emberiza citrinella and corn bunting Miliaria calandra, breeding performance per attempt was higher while populations declined. 6. Variation in annual survival and fledgling production per breeding attempt alone could not explain changes in abundance for at least seven species. This may suggest that changes in post‐fledging survival rates and/or the number of breeding attempts per year could have been important. 7. Management to improve over‐winter survival may be critical in reversing the population trends of most declining species, but such management might still best be directed at the breeding season. Post‐fledging survival rates and the number of breeding attempts made within a season are little‐studied demographic variables that are high priorities for future research and long‐term monitoring.

Local extinctions and changes in species richness of lowland farmland birds in England and Wales in relation to recent changes in agricultural land-use

Changes in agricultural land-use may have been responsible for contractions in range that have occurred in a number of bird species over the past three decades. This was considered by examining spatial change in the ranges of 21 farmland bird species at the scale of 10 km squares in relation to spatial change in agricultural land-use variables between the late 1960s and the late 1980s in lowland England and Wales. Seven species showed range declines (local extinction) exceeding 5% over this period and analyses focused on these: Grey Partridge Perdix perdix, Lapwing Vanellus vanellus, Turtle Dove Streptopelia turtur, Yellow Wagtail Motacilla flava, Tree Sparrow Passer montanus, Corn Bunting Miliaria calandra and Reed Bunting Emberiza schoeniclus. Individual species loss and change in species richness tended to be related to variables with strong regional trends, reflecting greater losses in western 10 km squares characterized by pastoral agriculture. It is unlikely that many of the variables selected in the regression models are, in themselves, the causal factors behind changes in the ranges of species and changes in species richness. Lapwing was an exception, agricultural variables associated with grassland being consistently selected. Principal Components Analysis (PCA) was applied to the agricultural variables. This identified a major gradient of change in cropping patterns, involving large increases in areas of wheat Triticum spp. and oilseed rape Brassica napus at the expense of barley Hordeum spp., bare fallow and grass. Local extinctions and change in species richness were consistently related to the first PCA axis, showing that local extinctions have occurred most in those squares where there had been relatively little change in crop types. The greater rate of local extinctions in pastoral regions may be associated with a number of factors, including changes in the management of grass and livestock, edge of range effects (where species in less favoured habitats are more likely to become locally extinct) and source-sink effects. These results highlight the need for further research into the effects of agricultural management on birds in pastoral systems.

Factors affecting corn bunting Miliaria calandra abundance in a Portuguese agricultural landscape

Breeding and wintering abundance of corn buntings in an agricultural landscape of Alentejo (southern Portugal) was assessed in relation to agricultural intensification and other environmental variables during 1994–1997, using distance sampling and multivariate regression. Bird abundance was lowest in intensively managed farmland in both seasons, and was related positively to fallow area in winter and to the presence of game management and oats in spring. Fallows and oats were associated with extensively managed farmland, but the implementation of a managed hunting regime was unrelated to agricultural intensification. The importance of extensive arable systems to corn bunting conservation is discussed.