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Long-term studies can provide powerful insights into the relative importance of different demographic and environmental factors determining avian population dynamics. Here we use 23 years of capture-mark-recapture data (1981-2003) to estimate recruitment and survival rates for a Sand Martin Riparia riparia population in Cheshire, NW England. Inter-annual variation in recruitment and adult survival was positively related to rainfall in the sub-Saharan wintering grounds, but unrelated to weather conditions on the breeding grounds. After allowing for the effects of African rainfall, both demographic rates were negatively density-dependent: adult survival was related to the size of the western European Sand Martin population (probably reflecting competition for resources in the shared wintering grounds) while recruitment was related to the size of the local study population in Cheshire (potentially reflecting competition for nesting sites or food). Local population size was more sensitive to variation in adult survival than to variation in recruitment, and an increase in population size after 1995 was driven mainly by the impact of more favourable conditions in the African wintering grounds on survival rates of adults. Overwinter survival in this long-distance Palaearctic migrant is determined partly by the amount of suitable wetland foraging habitat in the sub-Saharan wintering grounds (which is limited by the extent of summer rainfall) and partly by the number of birds exploiting that habitat. © 2013 British Ornithologists' Union. Source

There is considerable interest in understanding how management may help species and populations cope with climate change (climate change adaptation). I used a population model describing the demography of a southern range-margin European Golden Plover Pluvialis apricaria population vulnerable to climate change to assess the potential benefits associated with site-based adaptation management. Two forms of management were simulated: (1) counteracting management to reduce the severity of the negative climate change impacts, simulated by increasing tipulid (cranefly) abundance, and (2) compensatory management to increase populations through an alternative mechanism, simulated by manipulating nest and chick predation rates. A 1°C rise was estimated to require a doubling of cranefly abundance, or a 35% increase in nest and chick survival rates, to maintain a stable population. For a 2°C rise, a four-fold increase in craneflies or an 80% increase in survival rates would be required for population stability. A model based on likely realistic estimates of the magnitude of benefit associated with both adaptation management options showed that combined, they may significantly reduce the severity of population decline and risk of extinction associated with a relatively large increase in temperature of 5.8°C above 1960-90 levels. Site-based adaptation management may therefore increase the resistance of Golden Plovers to some degree of future climate change. This model framework for informing climate change adaptation decisions should be developed for other species and habitats. © 2011 British Trust for Ornithology. Journal compilation © 2011 British Ornithologists' Union. Source

Bradbury R.B.,RSPB | Stoate C.,Allerton Project | Tallowin J.R.B.,North Wyke Research
Journal of Applied Ecology | Year: 2010

1. Much policy and research in the UK and elsewhere in Europe has been directed towards the conservation of farmland birds. With changes in the drivers of agricultural land management, farmland bird conservation now needs to be considered alongside provision of a range of ecosystem services (ES) indicative of environmentally sustainable land-management.2. We explore the extent to which land management for farmland bird conservation provides 'cultural' ES, before assessing the potential consistency between management for bird species conservation and for a suite of ES that relate to the regulation of ecosystem processes.3. We discuss the potential for co-delivery and trade-offs between farmland bird conservation and regulating ES, at a range of locations and spatial scales.4. Potentially, action to enhance regulating services could provide some co-benefits for farmland bird conservation. However, more targeted management will still be required for certain species.5. Synthesis and applications. Integration of species conservation management practices, in this case in farmland, with provision of other ES will be a significant challenge to land management. This will demand careful planning, at multiple scales, to account for the range of synergies and trade-offs between services, the dependence of service provision on time and location of management, and the dependence of service benefit on the number, locations and preferences of human beneficiaries. © 2010 The Authors. Journal compilation © 2010 British Ecological Society. Source

Higgins J.W.P.-.,RSPB | Dennis P.,Aberystwyth University | Whittingham M.J.,Northumbria University | Yalden D.W.,University of Manchester
Global Change Biology | Year: 2010

Understanding the mechanisms by which climate change will affect animal populations is vital for adaptive management. Many studies have described changes in the timing of biological events, which can produce phenological mismatch. Direct effects on prey abundance might also be important, but have rarely been studied. We examine the likely importance of variation in prey abundance in driving the demographics of a European golden plover (Pluvialis apricaria) population at its southern range margin. Previous studies have correlated plover productivity with the abundance of their adult cranefly (Tipulidae) prey, and modelled the phenology of both plover breeding and cranefly emergence in relation to temperature. Our analyses demonstrate that abundance of adult craneflies is correlated with August temperature in the previous year. Correspondingly, changes in the golden plover population are negatively correlated with August temperature 2 years earlier. Predictions of annual productivity, based on temperature-mediated reductions in prey abundance, closely match observed trends. Modelled variation in annual productivity for a future scenario of increasing August temperatures predicts a significant risk of extinction of the golden plover population over the next 100 years, depending upon the magnitude of warming. Direct effects of climate warming upon cranefly populations may therefore cause northward range contractions of golden plovers, as predicted by climate envelope modelling. Craneflies are an important food source for many northern and upland birds, and our results are likely to have wide relevance to these other species. Research into the potential for habitat management to improve the resilience of cranefly populations to high temperature should be an urgent priority. © 2009 Blackwell Publishing Ltd. Source

Stanbury A.,RSPB
British Birds | Year: 2011

The Common Crane Grus grus was a familiar part of the UK avifauna up until the sixteenth century, although there is more evidence of a regular wintering population than widespread breeding. The species became extinct, probably through overexploitation, with the last evidence of breeding in England in 1542. Cranes subsequently became rare in the UK, but since the 1950s have become increasingly regular passage migrants. Two subadult Cranes, which arrived in the Norfolk Broads in autumn 1979, stayed and eventually bred there in 1981, and Cranes have bred in the Broads every year since. Population growth to 1997 was slow, mainly because of poor productivity, but since then success has improved and the number of pairs has increased steadily. Elsewhere, one pair has bred in Yorkshire since 2002, while up to three pairs have nested in the Fens of East Anglia since 2007. In 2010, there were 13-14 breeding pairs (which fledged eight young), three non-breeding pairs and a wintering population of c. 50 birds in the UK. It is unclear whether the new populations arose from emigration from the Broads or from continental Europe. The Common Crane remains a rare breeding species in the UK, but should continue to colonise new areas if present trends continue. It is not yet known whether one or more of the following factors - habitat availability, predation, human disturbance, collision risk - will constrain population growth. © British Birds 104 . August 2011. Source

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