Bridget M. Griffin

Bird ringing in Britain and Ireland in 2003

This is the 67th annual report of the British Trust for Ornithologys Ringing Scheme, covering work carried out, and data received, in 2003. During the year, reports of ringed birds were used to assess the post‐release survival of rehabilitated individuals. Varying proportions of different species were able to re‐enter the population, with Mute Swan Cygnus olor being the most successful. The origins and age structure of Guillemots Uria aalge ringed in Britain & Ireland and found dead after five major oil spills in European waters were found to vary depending on the location of the oil spill. More immature birds and birds from eastern colonies tended to be found after spills that were further south, whereas spills in the north had a greater effect on adults and birds from western colonies. Work on mass gain strategies in Blackbirds Turdus merula showed that they put on mass in winter, when the threat of starvation is greatest, as well as changing mass through the day, again probably in response to the likelihood of starvation. A study of the survival of passerines in the few weeks after fledging found that the survival rate during this critical period is only aboutone sixth of the rate in the rest of the first year of life. A study of the demography of Spotted Flycatcher Muscicapa striata showed that changes in post fleding survival were the most likely mechanism for the observed population decline. Data gathered as part of the Constant Effort Sites (CES) Scheme showed that adult abundance among resident species was generally high, following a good breeding season in 2002. When compared to 2002, fledgling productivity in 2003 was lower, probably as a resultof cold, wetweather during the breeding season. A total of 111 Retrapping Adults for Survival (RAS) studies submitted data covering 43 species. Target species for future workwere identified. Continuing work on the winter movements of farmland passerines showed variations in the distances moved by different species. Over 11,000 Swallows Hirundo rustica were ringed aspartofthe Swallow Roost Project. The total number of birds ringed (848,532) increased for the second year and was 5% above the mean of the previous five years (1998–2002). The recovery total (11,554) was also 5% up on the five‐year mean (1998–2002). Recoveries of 180 BTO‐ringed birds and 76 ringed abroad are presented in the report; those included confirm known or suspected movement patterns or are unexpected movements.

Bird ringing in Britain and Ireland in 2004

This is the 68th annual report of the British Trust for Ornithologys Ringing Scheme, covering work carried out, and data received, in 2004. During the year, changes in bird survival in relation to winter weather were studied. In almost all cases, there was a greater influence of weather on first‐year than adult survival. A paper providing guidelines to help those setting up demographic monitoring schemes for waders was produced, with ringing as a key component. Concern about a reduction in reporting rates of ringed birds led to a study of the changes. Declines were found across nearly all taxonomic groups and may reflect a combination of changes in reporting behaviour, ringing behaviour or bird behaviour. A study of the timing of muirburning used the ringing dates of pulli in conjunction with nest record data to assess its possible effect on breeding birds. There appears to be little reason for differences in cut‐off dates for muirburning in different regions and at different altitudes, but further work is required to quantify more fully the effects on moorland birds. Data gathered as part of the Constant Effort Sites (CES) Scheme showed increases in the numbers of adults of several, mainly migrant, species, possibly as a result of high rainfall in Africa south of the Sahara. Productivity was good for most species. Cettis Warbler Cettia cetti was added to the list of species covered and a study of habitat on CE sites showed that vegetation management mitigates the effect of habitat progression on catching rates. Data for 117 Retrapping Adults for Survival (RAS) studies were submitted. Over 12,000 Swallows Hirundo rustica were ringed as part of the Swallow Roost Project. The total number of birds ringed (881, 920) was the highest ever, showing an 18% increase on the mean of the previous five years (1999–2003). The recovery total (11,930) also increased (by 9% compared to the mean of the previous five years). Recoveries of 154 BTO‐ringed birds and 102 ringed abroad are presented in the report. They include records that confirm suspected or known migration patterns as well as the more unexpected movements

Bird ringing in Britain and Ireland in 2002

This is the 66th annual report of the British Trust for Ornithologys Ringing Scheme covering work carried out and data received in 2002. The BTO continues to work to understand the causes of bird population declines. During the year a major report on the demography of House Sparrows† and Starlings was completed. The work showed that while the decline in House Sparrows is likely to be due to a decline in the survival rate of first‐year birds, changes in productivity (the number of young birds entering the population) appear to have helped to halt the decline in recent years. For Starlings, changes in survival of first‐year birds was the best way of explaining the population decline, although changes in adult survival rate may also be implicated in eastern Britain. Work on wader age ratios showed that the proportion of juvenile waders in flocks caught in winter in Britain & Ireland may provide information about breeding success of high arctic species. Such data are hard to gather on the breeding grounds because of their remoteness and the dispersed nature of the breeding birds. A novel analysis of recoveries was able to show that the origins of Willow Warblers moving through Dungeness Bird Observatory in the autumn varied through the migration period and that the patterns of movement had changed in recent years. Data from the Constant Effort Sites (CES) Scheme showed that adult abundance in 2002 was generally lower than in 2001 following poor productivity in that year. Of nine significant changes in catches of adult birds between 2001 and 2002 eight were decreases (Blackbird, Sedge Warbler, Reed Warbler, Garden Warbler, Willow Warbler, Blue Tit, Great Tit and Chaffinch), with one increase (Bullfinch). Productivity generally improved when compared to 2001 with 18 species showing a statistically significant increase between the two years (Wren, Dunnock, Robin, Blackbird, Sedge Warbler, Reed Warbler, Whitethroat, Blackcap, Chiffchaff, Willow Warbler, Long‐tailed Tit, Blue Tit, Great Tit, Treecreeper, Chaffinch, Greenfinch, Bullfinch and Reed Bunting). Data sets for 110 studies of 42 species were submitted as part of the Retrapping Adults for Survival (RAS) Project. The number of birds ringed (791,074) increased, after the drop in 2001 as a result of some land access restrictions imposed due to Foot and Mouth Disease, and was 4% above the mean of the previous five years (1997–2001). The recovery total (11,042) was similar to the five‐year mean (1997–2001). Recoveries of 130 BTO‐ringed birds and 63 ringed abroad are presented in the report; those selected for inclusion confirm known breeding or wintering areas or migration routes and also show a number of significant or unusual movements.

Bird ringing in Britain and Ireland in 2001

This is the 65th annual report of the British Trust for Ornithologys Ringing Scheme covering work carried out and data received in 2001. As part of the BTOs 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 (1996–2000), 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 (1996–2000). 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 Egret involving Britain & Ireland, the first recoveries of BTO‐ringed Honey Buzzards, a BTO‐ringed American Golden Plover recovered in Italy, an Hungarian‐ringed Knot found in England and the first foreign‐ringed Yellow‐browed Warbler (from Norway) to be reported in Britain & Ireland.

Fattening strategies of British & Irish Barn Swallows Hirundo rustica prior to autumn migration

For migratory birds, regulation of energy reserves is crucial for survival during the migratory journey, and may also affect subsequent stages of the life cycle. Although Barn Swallows Hirundo rustica are able to feed en route, recent studies in Italy and Spain have demonstrated that they accumulate fat stores prior to departing for the wintering grounds. We investigated factors affecting pre-migratory body-mass gain in Swallows roosting at 41 sites in Britain & Ireland using data from 543 catches between July and September in 2002–06. Mean body mass of both adult and juvenile Swallows increased prior to migration, but adults gained more mass than juveniles. There was strong evidence that the increase was a result of birds building up fat reserves in preparation for migration. Swallows caught at more-southerly roosts developed larger fuel reserves than those caught in the north. The pattern of body-mass increase mirrored that of birds caught in southern Europe, although British & Irish Swallows gained less mass and fattening began earlier. These results suggest that British & Irish Swallows may stage in southern Britain, gaining sufficient fuel reserves to allow them to travel to the Continent, where further fattening is likely to occur.

Bird ringing in Britain and Ireland in 2007

This is the 71st annual report of the British Trust for Ornithologys Ringing Scheme, covering work carried out, and data received, in 2007. In partnership with EURING, a web‐based application was developed to map migration routes of waterfowl species identified as being those with the highest potential to carry Highly Pathogenic Avian Influenza H5N1 across Europe. This application used recovery data held in the EURING database. The 25th year of Constant Effort Site (CES) ringing demonstrated how the heavy rainfall during the summer of 2007 had a largely negative effect on breeding success, with productivity of ten species significantly lower than the long‐term average, although that of four species was significantly higher. These contrasting fortunes are likely to be related to the timing of the heaviest rains in relation to breeding stage. For several species, there were also continued declines in adult abundance and there is particular concern for Sedge Warbler, Reed Bunting, Lesser Whitethroat and Linnet, which reached their lowest‐ever levels since CES monitoring began. Data for 96 Retrapping Adults for Survival (RAS) studies were submitted, covering 34 species, including six Red‐listed species and 14 that are Amber‐listed. The total number of birds ringed (786,070) was 7% lower than the mean of the previous five years. This reduction may have been influenced by the heavy rainfall in 2007, which affected breeding success of some species and may have led to fewer opportunities for ringing activities. The recovery total (13,156) was higher than the mean of the preceding five years and the number of recoveries of foreign‐ringed birds (1,368) was the highest annual total ever reported. Recoveries of 223 individual birds are presented in the report. They include unexpected movements, movements that confirm suspected or known migration patterns, and longevity records.

Bird ringing in Britain and Ireland in 2005

This is the 69th annual report of the British Trust for Ornithologys Ringing Scheme, covering work carried out, and data received, in 2005. Important research on Oystercatchers Haematopus ostralegus in North Wales showed that survival of adults, recruitment of juveniles and mass of both adults and juveniles were lower during winters when there was mechanised dredging for shellfish. A study of weight changes of House Sparrows Passer domesticus in autumn and winter found that they spread their weight gain through the day, thus potentially decreasing their risk of predation, but increasing their risk of starvation. Data gathered as part of the Constant Effort Sites (CES) Scheme showed an annual increase in adult numbers for five species (one migrant and four residents) and an annual decrease for five species (four migrants and one resident). Productivity was variable with 11 species having above‐average productivity and 13 below‐average. Work began to develop methods to produce annual survival trends by integrating CES data from the 350 sites that have taken part in CES over the last 21 years. Data for 110 Retrapping Adults for Survival (RAS) studies were submitted. Over 13,000 Swallows were ringed as part of the Swallow Roost Project, which ran until 2006. The total number of birds ringed (873,581) was exceeded only in 2004 and was a 12% increase on the mean of the previous five years (2000–04). The recovery total (12,658) was the second highest in the last decade, being exceeded only in 2004, and was 9% higher than the mean of the previous five years. A total of 236 selected recoveries are presented in the report. They include unexpected movements and others that confirm suspected or known migration patterns.

Bird ringing in Britain and Ireland in 2006

This is the 70th annual report of the British Trust for Ornithologys Ringing Scheme, covering work carried out, and data received, in 2006. During the year recoveries of ringed birds were used to assess the possibility of highly pathogenic Avian Influenza H5N1being spread across Europe and into Britain by wild birds. Recovery reports were vital in understanding this risk and advising government. A study of wader survival using existing data showed that monitoring is possible, but is less effective in sites where there are low encounter rates. Constant Effort Site (CES) data show how widely adult numbers can vary from year to year, with six species showing a significant reversal in trend (with five having fallen) from the previous year. There is particular concern for Bullfinch as adult numbers decreased by 16% in 2006, a continuing downward trend that has seen numbers of the species halve since the 1970s. Five species showed a significant increase in productivity when compared to the previous year, while four showed a significant decrease. Data for 106 Retrapping Adults for Survival (RAS) studies were submitted. The final year of fieldwork for the Swallow Roost Project was completed. Although the total number of birds ringed (853,681) was lower than that in both 2005 and 2004, it was a 1% increase on the mean of the years 2002–05. The recovery total (13,785) was the highest since 1991, and was 16% higher than the mean of the previous five years. Recoveries of 251 individual birds are presented in the report. They include unexpected movements, movements that confirm suspected or known migration patterns, and longevity records.

Bird ringing in Britain and Ireland in 2000

This is the 64th annual report of the British Trust for Ornithologys Ringing Scheme presenting work carried out and data received in 2000. Ringing birds is an important tool for conservation and research, providing information on survival, productivity and movements of birds. Much progress has been made in developing Integrated Population Monitoring (IPM) models to identify key aspects of a species’ biology. Studies on Marsh and Willow Tits and on Bullfinches focussed on developing models for these species, which are of particular conservation concern. A further study described some advances in statistical theory that can be used in IPM models. A study of Redshank movements showed differences before and after closure of a tidal barrage in Cardiff Bay in south Wales. Data collected by the Constant Effort Sites (CES) Scheme showed mixed fortunes for breeding birds. Adult numbers increased significantly for four species (Long‐tailed Tit, Sedge Warbler, Reed Warbler and Whitethroat) and four species showed significant declines (Linnet, Garden Warbler, Blackcap and Willow Warbler). Similarly, productivity increased significantly for three species (Blue Tit, Blackcap and Willow Warbler) and decreased significantly for three species (Reed Warbler, Chaffinch and Bullfinch). Initial work on a project to develop standard CES methods across Europe is described. 101 datasets for 43 species were submitted for the Retrapping Adults for Survival (RAS) Project. The number of birds ringed in 2000 (734,235) was 8% lower than the five‐year mean 1995–1999. The recovery total (10,912) was 6% below the mean of the previous five years (1995–1999). Recoveries of 156 BTO‐ringed birds and 81 birds ringed abroad are presented in the report, including a number of significant movements of an unusual nature. Particularly noteworthy are the first report abroad of a BTO‐ringed Shorelark, the first BTO‐ringed Whinchat to be recovered on the wintering grounds and a Great Tit that was ringed at Rybachiy in Russia in September 1999 and recaught in Cleveland in February the following year.

Bird ringing in Britain and Ireland in 2009

This is the 73rd annual report of the British Trust for Ornithologys Ringing Scheme, covering data received and work carried out in 2009. Much of the research carried out during the year looked at ways to improve the analysis of ringing data to understand population change. This included producing survival rates from the Constant Effort Sites (CES) scheme for the first time and further developing methods of analysing our demographic data sets in an integrated manner. Research was also undertaken on the biometric data to investigate how individual condition responds to long‐term environmental change. CES data suggested that the low productivity in 2007 and 2008, combined with one of the coldest winters since 1995/96 for residents, contributed to reduced adult numbers in 2009 in many species. There were significant decreases in Wren Troglodytes troglodytes, Sedge Warbler Acrocephalus schoenobaenus, Reed Warbler A. scirpaceus, Blackcap Sylvia atricapilla, Lesser Whitethroat S. curruca, Willow Warbler Phylloscopus trochilus, Long‐tailed Tit Aegithalos caudatus, Blue Tit Cyanistes caeruleus, Great Tit Parus major, Treecreeper Certhia familiaris, Chaffinch Fringilla coelebs, Greenfinch Carduelis chloris and Reed Bunting Emberiza schoeniclus. However, a good breeding season, for both residents and migrants, resulted in significantly higher productivity for 15 species, but significantly lower for Willow Tit Poecile montana, compared to the long‐term mean (1983–2007). Data for 104 Retrapping Adults for Survival studies were submitted, covering 39 species, three quarters of which are Birds of Conservation Concern. The total number of birds ringed (935,867) was the highest ever recorded, and was over 10% higher than the mean of the previous five years. However, the total number of pulli ringed in 2009 (179,712) was only 5% higher than the preceding five‐year mean, while that of fully grown birds (756,155) was over 13% higher. The recovery total (14,643) was also high. However, this is partly due to changes in the way that records of colour‐ringed and other specially marked birds are stored. The number of recoveries of foreign‐ringed birds (1,314) was higher than the mean of the preceding five years, although this figure is influenced by varying response times of different ringing schemes. Recovery details for 250 individual birds are given in the final section of the report. They include movements that confirm suspected or known migration patterns, unexpected movements and longevity records.