Time filter

Source Type

Box, United Kingdom

Ewing S.R.,Royal Society for the Protection of Birds | Rebecca G.W.,Royal Society for the Protection of Birds | Heavisides A.,Scottish Raptor Study Groups | Court I.R.,Northern England Raptor Forum | And 4 more authors.
Bird Study | Year: 2011

Capsule The third national Merlin survey estimated a UK population of 1162 breeding pairs (95% CI: 891-1462). Aims To estimate the number of breeding Merlins (with associated 95% confidence intervals) in the UK and the four countries (Scotland, England, Wales and Northern Ireland), and to compare these with the relevant estimates from the 1993-94 Merlin survey. In addition, to calculate estimates of change for several regional populations with complete survey coverage during both national surveys. Methods A subset of 10-km squares (Raptor Study Group squares and randomly sampled squares) was surveyed across the breeding distribution of Merlins in the UK using standardised methods devised during the 1993-94 national survey. Results The population estimate for Merlins in the UK was 1162 breeding pairs, and in Britain was 1128 pairs (95% CI: 849-1427), which although 13% lower, was not significantly different from the British estimate of the 1993-94 survey. Scotland held the bulk (733 pairs) of the UK Merlin population, and smaller numbers of 301 pairs, 94 pairs and 32 pairs were estimated for England, Wales and Northern Ireland, respectively. The population estimate for Wales may have been biased upwards by low coverage in the south of the country. Marked declines were noted in several regional Merlin populations, particularly in areas of northern England. Conclusions The 2008 Merlin survey suggests that the population in Britain has remained relatively stable since 1993-94, but with local declines, particularly in northern England. Currently, little is known about important drivers of regional population change in Merlins, but changes in land-use, prey populations and climate are likely to be important factors. © 2011 British Trust for Ornithology. Source

Amar A.,RSPB Scotland | Amar A.,University of Cape Town | Court I.R.,Northern England Raptor Forum | Davison M.,Northern England Raptor Forum | And 4 more authors.
Biological Conservation | Year: 2012

Wildlife crime can be difficult to quantify, and its true impact on populations can be underestimated if rates are under-recorded. The illegal killing of birds of prey is an important form of wildlife crime, which in the UK, is often associated with land managed for the recreational shooting of red grouse Lagopus lagopus scoticus. In the UK, increases in peregrine falcons Falco peregrinus following recovery from organo-chlorine pesticides have not been uniform, with slow growth and localised declines in some areas, including those managed for red grouse shooting. In this study, we combined 1081 peregrine nest histories across northern England between 1980 and 2006 with a remotely sensed map of grouse moor management, to test whether breeding performance was lower in areas with active management for grouse shooting. Productivity of pairs on grouse moors was 50% lower than pairs breeding on non-grouse moor habitat. However, clutch size and brood size of successful nests did not differ between habitat types, suggesting that food constraints were unlikely to explain this difference. Population models suggested source-sink dynamics, with populations on grouse moors unable to sustain themselves without immigration. Population data confirmed that growth rates were indeed lower on grouse moors than on non-grouse moor sites. Analysis of wildlife crime data confirmed that persecution of the species was more frequent on grouse moors than in other habitat types. This population will be more secure, and better able to function as a barometer of environmental health and climate change, if illegal persecution of the species ceases on areas of land managed for grouse shooting. © 2011 Elsevier Ltd. Source

Discover hidden collaborations