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 decline in the thickness of eggshells of thrushes, Turdus spp., in Britain

Abstract: The thickness of eggshells of four species of thrush, Turdus spp., was estimated by an index based on the mass and linear dimensions of blown eggs in museum collections from Britain. Shell thickness was also measured directly for two species and was highly correlated with the index. Widespread declines in eggshell thickness since the nineteenth century were found in all species. There have been no previous reports of trends in eggshell thickness of this long duration and large spatial scale. The cause of the declines is unknown, but, for three of the four species, eggshell thinning began before the introduction of the organochlorine pesticide DDT, which caused eggshell thinning in predatory and fish–eating birds from 1947 onwards. The effect of acid deposition on the availability of calcium–rich prey is a plausible explanation.

Conservation management of Lapwing Vanellus vanellus on lowland arable farmland in the UK

Abstract: Lapwing Vanellus vanellus is known to be declining throughout much of its UK breeding range. The ecological requirements of the species are well known and a variety of mechanisms exist which can be implemented to help recovery. Arable options within agri-environment schemes can be used to provide breeding habitat throughout the species’ UK range, and targeted recovery projects have been shown to have the potential to deliver increases in breeding pairs at the local level. The farming community need to be made aware of the requirements of Lapwing if agriculture and conservation needs are to be integrated.

Summer diet and body condition of Song Thrushes Turdus philomelos in stable and declining farmland populations

Abstract: Summer diet and body condition were compared in two farmland Song Thrush Turdus philomelos populations in south-east England. One population on mixed farmland was stable and the other on arable farmland was rapidly declining. Summer diet was dominated by earthworms, snails, beetles and insect larvae (mainly Coleoptera and Lepidoptera). In both populations there was a pronounced seasonal decline in the quality of the diet, with preferred earthworms dominating prey items during March-April and snails dominating during June and July. Dry weather during late summer was associated with reduced proportions of earthworms and snails, and increased proportions of spiders in the diet, and dry soil conditions had a weak negative influence on the body weights of chicks (in the arable population) and adults. Despite a tendency for earthworms to constitute a higher proportion of the diet in the stable population, and for snails to constitute a higher proportion of the diet in the declining population, the body condition of chicks and adults appeared to be unrelated to diet composition and did not differ between study populations. Changes in agricultural practices have probably caused a major reduction in the availability of key summer food resources for Song Thrushes on lowland farmland, and we speculate that breeding thrushes mitigate the impacts of food shortage on chicks by confining their nesting attempts to localities and periods where invertebrate food resources are adequate to raise a brood of young.