Royal Society for the Protection of Birds

About: Royal Society for the Protection of Birds is a nonprofit organization based out in Sandy, United Kingdom. It is known for research contribution in the topics: Population & Biodiversity. The organization has 670 authors who have published 1425 publications receiving 88006 citations. The organization is also known as: RSPB & Plumage League.

Long-term impact of changes in sheep Ovis aries densities on the breeding output of the hen harrier Circus cyaneus

Abstract: Summary 1. Livestock grazing is an important form of land use across the globe and changes in grazing pressure can have profound effects on vertebrate populations. 2. In Scotland, over the last decade sheep numbers in many areas have declined from historically high levels, providing an opportunity to explore the implications of these declines for biodiversity. 3. The hen harrier Circus cyaneus is a bird of high conservation importance in the UK, and a species that may be heavily influenced by the indirect effects of sheep on habitat and prey. The hen harrier population on the Orkney Islands in Scotland has been monitored since 1975 and represents an ideal case study for considering the impact of sheep de-stocking on a key predator. 4. Declines in the harrier population were associated with a doubling in sheep numbers between the early 1980s and the late 1990s. Subsequently, as sheep numbers have fallen the harrier population has recovered. These changes indicate an association but no clear mechanism, so we tested whether reductions in sheep numbers have led to increases in harrier prey or preferred foraging habitat. We then tested whether breeding output over the last 33 years correlates with sheep stocking levels or variation in weather conditions (rainfall and temperature). 5. Orkney sheep numbers declined by about 20% between 1998 and 2008. Surveys in 1999 ⁄ 2000 and repeated in 2008 showed increases in rough grassland, the preferred harrier foraging habitat, and increases in a key prey species, the Orkney vole Microtus arvalis orcadensis. 6. Overall, hen harrier breeding output over the last 33 years was significantly negatively correlated to both sheep abundance and spring rainfall. 7. Synthesis and application. This study provides strong evidence for the consequences of changes in sheep numbers on a top predator. Our results indicate that reductions in sheep numbers are likely to prove beneficial for some upland species, particularly small mammals and their predators.

Impact of an exceptional winter flood on the population dynamics of bearded tits (Panurus biarmicus)

Abstract: Mark–recapture data are used to investigate the impact of an exceptional winter flood on the population dynamics of an isolated bearded tit Panurus biarmicus population in north-west England. Adult numbers increased threefold (from 60 to 180 individuals) between 1992 and 2000, but declined by 94% during 2000/2001. This large reduction in numbers was caused by severe over-winter mortality associated with a prolonged flood of the Phragmites litter layer, the main winter foraging habitat of bearded tits, followed immediately by cold weather. At the end of the flood, bearded tits were 20% lighter than during previous winters. Population changes in other years were accurately predicted by annual variation in recruitment, and there was evidence that recruitment was higher following the introduction of artificial nest boxes and was density dependent. This study highlights the potential threat to bearded tits in Europe of predicted increases in the frequency and extent of winter flooding, and the potential utility of measures like artificial nest boxes that aim to promote recruitment. Recent extensions of methodology now permit a detailed exploration of animal population dynamics from mark–recapture data alone.

How butterflies keep their cool: Physical and ecological traits influence thermoregulatory ability and population trends

Abstract: 1. Understanding which factors influence the ability of individuals to respond to changing temperatures is fundamental to species conservation under climate change. 2. We investigated how a community of butterflies responded to fine‐scale changes in air temperature, and whether species‐specific responses were predicted by ecological or morphological traits. 3. Using data collected across a UK reserve network, we investigated the ability of 29 butterfly species to buffer thoracic temperature against changes in air temperature. First, we tested whether differences were attributable to taxonomic family, morphology or habitat association. We then investigated the relative importance of two buffering mechanisms: behavioural thermoregulation versus fine‐scale microclimate selection. Finally, we tested whether species' responses to changing temperatures predicted their population trends from a UK‐wide dataset. 4. We found significant interspecific variation in buffering ability, which varied between families and increased with wing length. We also found interspecific differences in the relative importance of the two buffering mechanisms, with species relying on microclimate selection suffering larger population declines over the last 40 years than those that could alter their temperature behaviourally. 5. Our results highlight the importance of understanding how different species respond to fine‐scale temperature variation, and the value of taking microclimate into account in conservation management to ensure favourable conditions are maintained for temperature‐sensitive species.

Determination of the diet of the stone curlew (Bwhinus oedicnemus) by faecal analysis

Abstract: The value of faecal analysis for estimating the composition of the diet of stone curlews was assessed by examination of the faeces of a captive bird fed on a measured diet. Remains of soft–bodied prey were under–represented in the faeces but the results could be adjusted to allow for this. Estimation of the size of prey was possible by measurement of remnants such as earthworm chaetae and insect mandibles. In some types of prey large specimens left more remnants than small ones and a correction was devised to allow for this. Regurgitated pellets contained large, hard remains and there was no trace of some important prey types such as earthworms. A method is described for estimating the composition of the diet of the wild stone curlews from counts of prey remains in their faeces.

A preliminary assessment of the contribution of nature reserves to biodiversity conservation in Great Britain

Abstract: As a signatory of the Convention on Biological Diversity, the United Kingdom (UK) Government is obliged to conserve and enhance biodiversity. One step towards addressing this goal is to determine the level of biodiversity conservation already achieved within the current array of protected areas. We used national distribution data for ten taxonomic groups, and location information for three reserve networks, to assess the contribution of nature reserves to biodiversity conservation in Great Britain at the 10 km square (=100 km2) resolution. For several taxonomic groups, 10 km squares containing nature reserves had a significantly greater overlap than random networks with both hotspots (areas of high species richness) and complementary areas (sets of sites within which all species are represented). In addition, more than 94% of species from each taxonomic group have been recorded within the 10 km squares of the three reserve networks. These results provide some encouragement in terms of the UK meeting its commitment to conserve biodiversity.