Summary 0[ The present study investigated breeding success and causes of breeding failure of curlew\ a species for which the UK holds internationally important breeding numbers[ Studies were undertaken between 0882 and 0884 in two areas of Northern Ireland\ where the species| breeding range has recently contracted and breeding numbers are declining[ Avian nest predators were abundant in both areas\ whereas foxes were abundant on the Antrim study area but generally were absent from the Lough Erne study area\ which was mainly islands[ 1[ Productivity was estimated to be 9=03Ð9=15~edglings per pair in Antrim and 9=19Ð 9=36~edglings per pair on Lough Erne[ These _gures are lower than most estimates of productivity from other studies of breeding curlew[ The di}erences between the recorded productivity levels and those estimated to be required to maintain a stable population are su.cient to account for the observed decline in Northern Ireland|s breeding curlew population[ 2[ Predation was the main proximate cause of breeding failure\ with nest predation being of most importance in reducing productivity[ Only 2=5Ð08=9) of all nests hatched on each study area in each year\ with nest predation accounting for 74Ð86) of failures[ Survival of chicks from hatching to 20 days of age was 27=4) in Antrim and 08=0Ð18=1) on Lough Erne[ Predation accounted for 63) of chick mortality[ 3[ Nest failure rates were not related to the vegetation height around nests nor to clutch laying date on either study area[ They di}ered among the islands and one shoreside site on Lough Erne[ Almost all nest predation on Lough Erne was attribu! table to avian predators\ but in Antrim foxes probably accounted for most nest predation[ The likelihood of predation on chicks was not related to their hatching date\ hatching weight or body condition[ 4[ The results from this study suggest that predation rates on curlew nests in Northern Ireland may have increased in recent decades[ Levels of predator control in Northern Ireland have declined but there have also been considerable changes in land!use that could bene_t generalist predator species or increase the vulnerability of curlew nests to predation[ It is recommended that large!scale trials of legalized predator control and land!use manipulation should be undertaken to identify appropriate conservation management methods[ Key!words] breeding waders\ nesting success\ population decline\ predation[ Journal of Applied Ecology "0888# 25\ 48Ð63

No abstract

Summary1. Changes in large-scale land use may fragment and degrade habitats, affecting animal species adapted to these habitats. In the UK uplands for example, changes in sheep and game management, and afforestation, have altered the configuration of internationally important moorland habitat and are predicted to have increased predation pressure for a globally unique suite of breeding birds of international conservation importance. 2. Some of these upland bird species have declined, with particular concern over groundnesting waders. Using resurveys of the rapidly declining Eurasian curlew Numenius arquata as a focal species of global conservation concern, we investigate whether upland land use predicts low nesting success and population decline. 3. Curlew population changes over an 8-to 10-year period were positively related to gamekeeper density (a surrogate of predator control intensity) and inversely to the area of woodland surrounding sites, as a likely source of predators to adjacent open ground. Model predictions suggest that increasing woodland cover from 0% to 10% of the land area within 1 km of populated sites requires an increase in human predator control effort of about 48%, to a level associated with high-intensity grouse production, to achieve curlew population stability. 4. Curlew nesting success, known to be a key driver of population trends, was also positively related to gamekeeper density and inversely to woodland area surrounding sites, providing a plausible mechanistic link between land use and population change. 5. Synthesis and applications. Upland land use is associated with curlew declines, with predation a likely mechanism, and this may apply to other breeding waders. The removal of isolated woodland plantations from otherwise unafforested landscapes may help reduce predation pressure across a range of systems including moorland. However, direct predator control may also be important to conserve ground-nesting birds in these landscapes, for example, where moorland management and forestry coexist as major land uses. Predator control may also mitigate climate change effects by enhancing wader productivity, particularly where climate effects coincide with changing land use. Emerging land uses in open landscapes, including native woodland restoration and wind farms, require careful siting to minimize further impacts on open-area breeding birds.

Summary1. Understanding how demographic variation translates into variation in population growth rate (k) is central to understanding population dynamics. Such understanding ideally requires knowledge of the mean, variance and covariance among all demographic rates, allowing the potential and realized contribution of each rate to k to be estimated. Such studies require integrated monitoring of all demographic rates across multiple years and are consequently rare, particularly in declining populations and for species with less tractable life histories. 2. We used 12 years of comprehensive demographic data from a declining ring ouzel (Turdus torquatus) population to estimate the mean, variance and covariance in all major demographic rates and estimate potential and realized demographic contributions to k. 3. Population size decreased from 39 to 13 breeding pairs ()67%) and mean k was 0AE91 during 1998-2009. This decrease did not reflect a substantial concurrent decrease in any single key demographic rate, but reflected varying combinations of demographic rates that consistently produced k < 1. 4. Basic prospective elasticity analysis indicated that k was most sensitive to adult survival, closely followed by early season reproductive success and early brood first-year survival. In contrast, integrated elasticity analysis, accounting for estimated demographic covariance, indicated that k was most sensitive to early brood first-year survival, closely followed by re-nesting rate, early season reproductive success, late-brood first-year survival and adult survival. 5. Retrospective decomposition of variance suggested that first-year survival contributed most to observed variation in k. 6. However, demographic comparison with other related species suggested that adult survival, but not reproductive success or post-fledging survival, averaged lower than expected throughout the 12-year study.7. These data demonstrate that multiple approaches, including comprehensive demographic and comparative analyses and due consideration of conflicting answers, may be necessary to accurately diagnose the demographic basis of population change.

We reviewed the literature to determine the importance of invertebrates for moorland‐breeding birds and considered our findings with respect to the conservation of such species in the UK. The diets of many moorland birds consist predominantly of invertebrates, with a wide range of taxa recorded in the diets of moorland birds during the breeding season. Relatively few taxa (Arachnida, Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera and Oligochaeta) were widely taken, with Diptera and Coleoptera being the most important. Among these latter two insect orders, Carabidae, Curculionidae, Elateridae and Tipulidae were the most important families. Comparisons of the diets of bird families, treated separately according to whether data were derived from adults or chicks, showed that waders take more interstitial invertebrates than passerines, which themselves take more foliage invertebrates. Although we lack detailed experimental data with which to demonstrate the direct effect of particular moorland management prescriptions on some of these key invertebrate taxa for breeding birds, available data suggest that management regimes that create a mosaic of habitats are likely to be most beneficial. In particular, heterogeneity in vegetation structure and species composition, and the presence of wet flushes associated with the synchronized spring emergence of adults of certain insect species, are likely to increase invertebrate food resources for birds.