Bird ringing in Britain and Ireland in 2001

Abstract

This is the 65th annual report of the British Trust for Ornithology's Ringing Scheme covering work carried out and data received in 2001. As part of the BTO's production of the landmark Migration Atlas: movements of the birds of Britain & Ireland, which will review movements of birds using Britain & Ireland, novel approaches to the investigation of the movement patterns and distances were developed. These allow the objective comparison of whether different species are sedentary, short-distance or long-distance migrants and the investigation of differential migration between birds of different age and sex. The BTO continues to carry out a programme of work investigating the declines in bird populations. In 2001, an investigation of Song Thrush population dynamics showed that the survival rates of young birds was key in the population decline; reduction in survival rates also seemed to have driven the fall in numbers of Marsh Tits. Work on movements of waders between roosts on the Moray Basin showed little movement for most species; important information when the possible effects of disturbance are being considered. An investigation of the biometrics of the Redshank wintering on Severn Estuary found that the proportions of Icelandic and British breeders varied between sites; again an important factor in assessing the possible consequences of disturbance. A pilot project, which is investigating the collection of data on movements and demography of farmland passerines in winter is described. Data collected as part of the Constant Effort Sites (CES) Scheme showed significant changes in the numbers of seven species between 2000 and 2001. Of these, five resident species (Blackbird, Blue Tit, Great Tit, Chaffinch and Greenfinch) and one migrant (Whitethroat) showed increases. Only one species (Willow Warbler) decreased. By contrast, productivity tended to be low with 11 species, both residents (Dunnock, Robin, Blackbird, Long-tailed Tit, Blue Tit, Greenfinch and Reed Bunting) and migrants (Sedge Warbler, Reed Warbler, Blackcap and Chiffchaff) showing significant declines. Progress on the EURO-CES project, which aims to develop standard protocols for CES fieldwork and data capture across Europe is reported. Data sets for 86 studies of 42 species were submitted as part of the Retrapping Adults for Survival (RAS) Project. The first detailed analysis of Pied Flycatcher data from RAS-type studies showed that survival rates vary between different areas of the country and confirms the value of this project. The numbers of birds ringed in 2001 (648,936) was 16% below the mean of the previous five years (1996)(1997)(1998)(1999)(2000), largely as a result of Foot and Mouth Disease, which restricted the areas ringers had access to. The recovery total (10,692) was 6% lower than the five-year mean (1996)(1997)(1998)(1999)(2000). Recoveries of 195 BTO-ringed birds and 77 birds ringed abroad are presented in the report and include a number of unusual or significant movements. Of particular note are the first recovery of a Great White E...

Bird ringing in Britain and Ireland in 2002

“…Fifteen species met these criteria, seven of these showing a decrease. Just over half of these species (Mallard, Sparrowhawk, Common Tern, Razorbill, Puffin, Starling, Goldfinch and Siskin) appeared in the corresponding table in the 2001 report (Clark et al 2002a).…”

“…The 2001 report (Clark et al 2002a) contained the most recent five-yearly summary tables of all recoveries received since the Scheme began in 1909, broken down by country of finding or origin. In addition, the 2001 report included longevity records for all species.…”

The influence of climatic conditions in breeding grounds and migratory flyways on a subalpine Norwegian Willow Warbler (Phylloscopus trochilus) population

“…The recovery from this great Sahelian drought has also been monitored by analyses of satellite images which show an increase in greenness over large parts of the Sahel since the early-and mid-1980s, when the peak of this Sahelian desiccation was seen (Herrmann et al 2005). Some significant reductions in long-distance migrant species from the 1960s towards the 1990s were found to be correlated with changes in rainfall in their African winter quarters (Winstanley et al 1974, Peach et al 1991, Boehning-Gaese & Bauer 1996, and lately more stable situations, and even some recoveries, after the termination of this long dry spell are observed for some of the same African migrants (e.g., Clark et al 2002, Thingstad et al 2006, Karlsson 2007, Balmer et al 2013.…”

Ringing recoveries confirm higher wader mortality in severe winters

“…The scheme covers Britain & Ireland and, each year, approximately 40,000 waders are ringed and over 400 are subsequently reported (eg Clark et al 2002). Although the numbers ringed in different areas of the country are not currently recorded electronically, the distribution of reports of dead ringed birds gives an indication of the spatial and temporal distribution of mortality.…”