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Private gardens are recognised as potentially important refugia for butterflies. Yet little is known about how gardens might be contributing to butterfly conservation, as their restricted accessibility has meant that garden habitats are not well‐represented in traditional monitoring schemes.Garden BirdWatch (GBW) is the UK's largest structured bird survey, comprising over 25 years of weekly bird counts from more than 14,000 gardens, predominantly occupying suburban and rural locations. Since 2007, a subset of GBW participants have additionally recorded the weekly abundances of butterflies. Using data for 14 seasons (2007–2020) from 7971 gardens with consistent butterfly monitoring, we present the first garden‐specific, national trends for 22 widespread butterfly species (37% of all UK butterflies).Half of the species investigated increased significantly in abundance in gardens between 2007 and 2020. Conversely, only one species, Wall (Lasiommata megera), showed a marginal reduction, though this change was not statistically significant.A strong, positive association between these new, habitat‐focused trends and those for UK butterflies more broadly, previously reported by the UK Butterfly Monitoring Scheme (UKBMS), indicates that patterns of abundance in gardens are largely a reflection of the changes that are occurring nationally. However, butterflies do appear to be faring better in gardens compared to the wider landscape. Averaging trends across non‐migratory species revealed that GBW recorded significantly greater increases over time than UKBMS.Effective monitoring of butterflies in gardens can produce reliable and informative population trends, and it provides important evidence of the significant role gardens play in sustaining butterfly populations. [ABSTRACT FROM AUTHOR]

Blue Tits Cyanistes caeruleus and Great Tits Parus major wintering in rural areas tended to move further to breed the following breeding season and more frequently cross the urban–rural boundary, than did those wintering in urban gardens. To explore and quantify the movements of birds from winter to breeding season locations across the urban–rural ecotone at the boundary of a large urban area. Birds were colour-ringed at rural and urban/suburban garden ringing sites during the winter. This was followed by breeding season surveys and resighting in the surrounding areas to quantify the movements of colour-ringed birds and changes in habitat selection between seasons. Blue Tits and Great Tits ringed in winter in rural areas tended to move further and selected more urbanized breeding territories the following spring than did urban/suburban garden-ringed conspecifics. This shows that the populations were connected across the urban–rural ecotone by the seasonal movements of individuals, but that net movement was from rural wintering areas to urban breeding habitat. The results suggest that rural populations may not be subsidized by urban wintering birds and winter supplementary feeding, but that the resources in gardens within urban areas, perhaps spring/summer feeding and nestboxes, draw birds in to breed. Combined with independent evidence for lower breeding success in urban areas, this may show the operation of source-sink dynamics. The results suggest important implications for connections between populations, the conservation value of urban areas and potential for the spread of disease, but further work is required to extend evidence and inference to other regions and species. Nevertheless, the approach used here provides a scalable study model that can be applied in other contexts. [ABSTRACT FROM AUTHOR]

Capsule: A playback survey comprising two visits to woodland in early spring can reliably detect Marsh Tits Poecile palustris and permit reasonable estimation of the number of territories. Aims: To assess the efficacy of an efficient survey method for detecting and estimating populations of Marsh Tits. Methods: Detection probability of colour-marked Marsh Tits, surveyed using playback, was assessed with Cormack-Jolly-Seber models. Reliability of territory estimates was compared between colour-marked and largely or wholly unmarked populations. Results: Playback surveys over two visits in early spring were highly effective in detecting individual Marsh Tits. Territory estimates were similar for woods in years where less than 20% of the population was marked compared to years when a higher proportion of birds were colour-marked, although territories may be underestimated in larger woods with unmarked populations. Conclusion: A playback survey comprising two visits in early spring is recommended as an efficient method of surveying Marsh Tit populations and locating individuals. A survey protocol is suggested. [ABSTRACT FROM AUTHOR]

Biometrics are commonly used to compare bird species. For Marsh Tits and Willow Tits in Britain there are few biometric data from birds of known age and sex, despite their value for population analyses in estimating the proportion of males and females in samples. Comparing measurements between the two species could also aid identification and the monitoring of these declining species in Britain. We present biometrics for a large sample of Marsh Tits of known age and sex, and new data for Willow Tits, which act as reliable reference material. Overall, adults of both species were larger than first-years and males were larger than females, but not among first-year Willow Tits. Marsh Tits were slightly larger and heavier than Willow Tits, but Willow Tits had proportionately longer tails. Discriminant analyses produced new equations for separating the species based on wing length and the measurement between the shortest and longest tail feathers. Probabilities were generated for estimating Marsh Tit population structure from samples of ringing data, but there was a greater overlap between sexes in Willow Tit measurements. We conclude by discussing issues of measurement accuracy and consistency in the collection and analysis of biometric data. [ABSTRACT FROM PUBLISHER]

CapsuleAll British Marsh Tits belong to subspeciesPoecile palustris dresseri, being smaller than nominateP. p. palustrisof central Europe. AimsDetermining the subspecies of Marsh Tit in Britain to test whether ssp.P. p. palustrisoccurs in northern England and Scotland, by assessing regional variation in size compared with central European birds. Methods1147 wing length and 250 tail length measurements from 953 Marsh Tits were compared between eight British locations to test for regional variation. Biometrics were compared between birds from Britain and six locations within the continental European range of ssp.palustris. ResultsThere was no regional variation in wing or tail lengths among British Marsh Tits, indicating that all resident birds belong to ssp.dresseri. There was no evidence supporting the existence of ssp.palustrisin northern England. British birds were significantly smaller than those from continental Europe, with proportionately shorter tails, consistent across all age and sex classes. ConclusionAll British Marsh Tits should be considered as ssp.dresseri, with ssp.palustrisbeing limited to continental Europe. With no evidence of regional variation in size within Britain, reliable sexing methods based on biometrics could be applied in demographic studies throughout the country. [ABSTRACT FROM PUBLISHER]

CapsuleSeasonal variation in garden House Sparrow numbers provides a tool to examine overall annual productivity, measuring the combined success of multiple breeding attempts and post-fledging survival. AimsTo develop a metric to use British Trust for Ornithology (BTO) Garden BirdWatch (GBW) data to measure annual productivity in House Sparrows across regions and habitats exhibiting contrasting population trends. MethodsWe examine variation in annual productivity by quantifying the height of the seasonal peak of garden House Sparrows relative to pre-breeding numbers. We use BTO Nest Record Scheme (NRS) data to explore the demographic drivers of variation in this metric and relate differences to BTO/Joint Nature Conservation Committee/Royal Society for Protection of Birds Breeding Bird Survey regional population trends. ResultsGBW annual productivity was similar between rural and urban gardens but was lower in the south and the east of Britain (1.32 fledglings per adult), where populations are declining, than in the north and west where populations are stable (1.37 fledglings per adult). Analysis of NRS data showed similar regional variation in clutch and broods sizes. ConclusionThe intensity of effort required to measure breeding success directly through nest monitoring has limited the scale of data collection but these results suggest that Garden BirdWatch (GBW) data can provide a measure of annual productivity across multiple sites. Regional variation in annual productivity (primarily driven by reduced clutch sizes) mirrors population trends, suggesting that reduced breeding success may be influencing House Sparrow population recovery. [ABSTRACT FROM AUTHOR]

This is the 76th annual report of the British Trust for Ornithology's Ringing Scheme, covering work carried out and data processed in 2012. Demographic integrated population monitoring has been the focus of the Scheme priorities in recent years and models that integrate ringing and nest record data and abundance trends were built for ten species for which sufficient data were available. Population drivers vary between species but they can be split between changes in breeding success, survival, or both. Multi-brooded species exhibited more seasonal variation in reproductive output than single-brooded species. In particular, migratory species showed a seasonal decrease in fledgling output, as do single-brooded species while residents generally showed a seasonal increase in productivity. Constant Effort Site (CES) data showed long-term (1984–2011) declines in four long-distance migrants and five resident species. However, four species (two short-distance migrants and two residents) have increased over the same period. Productivity of migrants monitored by CES was poor in 2012: seven of the eight species showed significant reductions in productivity compared to the five-year average and had the lowest productivity since CES began in 1983. Breeding performance of resident birds was low in 2012, with juvenile:adult ratios significantly lower than those calculated over the preceding five years for 10 of the 16 species. The number of CE sites increased in 2012, with data submitted for 125 sites, the highest total for a decade. The number of active RAS projects increased to 163 in 2012, with 21 new projects, eight of which involved RAS target species. In 2012 the total number of birds ringed (970,957) was the second highest recorded, and included 408,225 first-year birds, 377,199 adults (birds in their second calendar year or older), 23,772 unaged birds and 161,761 nestlings. In addition, there were 249,551 recaptures of ringed birds at or near the ringing site. The reduction in numbers ringed compared to 2012 was probably the result of the record wet weather that most of Britain & Ireland experienced in spring and summer 2012. A total of 18,693 BTO-ringed birds were recovered in 2012, which was lower than in 2011 but higher than in any previous year. This is the result of an increased number of birds ringed in the past 10 years, an increasing number of colour-ringed and tagged birds and subsequent resightings, more ringers within the Ringing Scheme, efforts to increase reports from members of the public of both metal and colour-ringed birds and an improvement in the way recoveries are processed. Recoveries of 22 BTO-ringed and 11 foreign-ringed individual birds that have extended our knowledge of movement of the species or constitute a new longevity record are presented. In total 44,895 nest records were submitted in 2012, the highest annual submission since the scheme began. Of these, 81% originated from England, 9% from Wales and 9% from Scotland, the remaining 1% divided equally between Northern Ireland and the Republic of Ireland. Submissions from England, Scotland and Northern Ireland have all risen by similar proportions since 2007 (18–22%), while those from Wales have increased by 34% over the same period. Long-term annual productivity trends have been calculated for three additional species. Long-term productivity trends were significant for 40 of the 72 species monitored and nine of these trends were negative, indicating a decline in breeding success over time. [ABSTRACT FROM AUTHOR]

This is the 75th annual report of the British Trust for Ornithology's Ringing Scheme, covering data received and work carried out in 2011. A review of priorities for the Scheme identified the need to increase submission of nest records through the Nest Record Scheme and to extend the network of Retrapping Adults for Survival (RAS) studies. Collection of different demographic parameters from the same site (eg nest records, numbers of breeding pairs, adult survival, etc) can provide a powerful tool to identify reasons for population change. Constant Effort Sites (CES) data showed long-term declines in abundance for four migrants (Willow Warbler Phylloscopus trochilus, Lesser Whitethroat Sylvia curruca, Sedge Warbler Acrocephalus schoenobaenus and Reed Warbler Acrocephalus scirpaceus) and three resident species (Willow Tit Poecile montana, Song Thrush Turdus philomelos and Reed Bunting Emberiza schoeniclus). Robin Erithacus rubecula and Reed Bunting had the lowest survival rates since CES began and survival-rate estimates were also significantly below average for Long-tailed Tit Aegithalos caudatus and Wren Troglodytes troglodytes, two small resident species that are particularly vulnerable to cold weather. Abundance of Blue Tit Cyanistes caeruleus, Great Tit Parus major, Goldfinch Carduelis carduelis and Bullfinch Pyrrhula pyrrhula recorded by CES increased. Nine of the 16 resident species covered by CES also had higher-than-average productivity, in particular the highest ever recorded for Dunnock Prunella modularis, Chaffinch Fringilla coelebs and Bullfinch. The number of Constant Effort Sites increased in 2011, with a higher percentage of reedbed habitat covered by the scheme, but fewer dry and wet scrub sites. In 2011 the number of RAS projects increased by 34 to 158. Survival trends were generated for 46 species and the use of colour marks has been promoted to increase the resighting probability of trap-shy species such as House Sparrow Passer domesticus and Starling Sturnus vulgaris, and for species with low recapture probability such as seabirds. As in 2010, the total number of birds ringed in 2011 (1,151,665) was the highest ever. It included 540,696 first-year birds, 383,136 adults (birds in their second calendar year or later) and 27,495 unaged birds. All ringing data for 2011 were computerised. In addition, there were 166,061 recaptures of ringed birds at or near the ringing site. The increased numbers of fully grown birds ringed is probably due to three main factors: high survival of some species, as suggested by CES results, combined with high productivity in 2011 and the increasing number of ringers in the Scheme catching higher numbers of birds. In total 20,702 BTO-ringed birds were recovered (found dead or recaptured away from the ringing site) in 2011, the highest ever as a result of the increased number of birds ringed in the past decade, combined with efforts to increase reports of ringed birds by the public, an increasing number of colour-ringing projects and associated resightings, and a change in the way recoveries are processed. Recoveries of 17 BTO- and 13 foreign-ringed birds that have extended our existing knowledge of movements of a species, are unusual movements, or are a new longevity record are also presented. In 2011 40,845 nest records were submitted (over 70% electronically), the highest total since 1998. Of these, 82% originated from England, 9% from Wales and 8% from Scotland, with the remaining 1% divided equally between Northern Ireland and the Republic of Ireland. Long-term nest productivity trends (1966–2010) were significant for 36 of the 71 species for which sufficient data were available, and seven of these (Nightjar Caprimulgus europaeus, Tree Pipit Anthus trivialis, Willow Warbler, Bullfinch, Coal Tit Periparus ater, Treecreeper Certhia familiaris and Chaffinch) showed a significant decline over time. The 2011 breeding season was characterised by an early start compared to the previous five years, possibly due to the warmest April on record. [ABSTRACT FROM AUTHOR]

This is the 74th annual report of the British Trust for Ornithology's Ringing Scheme, covering data received and work carried out in 2010. Analytical work in the year concentrated on considering how we can improve demographic monitoring, an increasing focus for the Scheme. A broad review of the availability of demographic and count data for terrestrial-breeding species was carried out. This work will be further extended in 2011. To inform conservation we need to build population models for species with a range of ecologies and occupying different habitats. Reports of ringed birds make a large contribution to our understanding of two key demographic parameters – survival and dispersal. An analysis of Chiffchaff Phylloscopus collybita recovery data from across Europe suggested they are tending to migrate south later and north earlier over time. There is also a suggestion that the migratory journey is shortening. Analysis of biometrics of birds wintering in Britain showed that they are largely from the breeding populations of the nominate race in Britain and the near Continent. Constant Effort Sites (CES) data showed that, for seven of the 24 species monitored, there was a significant decrease in adult abundance compared to the mean of the previous five years. As six of these species were residents, this may have been a result of the second severe winter in succession, although there was a short-term increase for Long-tailed Tit Aegithalos caudatus, which is usually affected by cold winters. The adult abundance of several long-distance migrants also increased. A long-term decline (1984–2000) is, however, still evident for five migrants and three residents, although for Willow Tit Poecile montana and Linnet Carduelis cannabina the sample sizes are low. The abundance of the short-distance migrants, Blackcap Sylvia atricapilla and Chiffchaff, has increased, possibly as a result of climate change. Productivity was higher than the mean of the previous five years for 12 species with the long-term trend increasing for eight species – four migrants and four residents. The only significant decreases were for Blackbird Turdus merula and Long-tailed Tit, possibly as these species breed early and were affected by the severe winter. Dry summer weather is also likely to have contributed to the low productivity of Blackbirds and increasingly dry summers may be implicated in the long-term declines in productivity for both Blackbird and Song Thrush Turdus philomelos. Long-term trends in survival rates were produced using CES data for the first time in 2010. These suggested that the cold winter weather in 2009–10 reduced the survival rate of resident ground-feeding insectivores such as Dunnock Prunella modularis, Blackbird, Wren Troglodytes troglodytes and Robin Erithacus rubecula. Survival rates of migrants were relatively high, particularly for Garden Warbler Sylvia borin and Sedge Warbler Acrocephalus schoenobaenus, possibly as a result of good conditions on the wintering grounds or passage sites. Data for 129 Retrapping Adults for Survival (RAS) studies covering 39 species were submitted. For the first time we were able to calculate good or moderate annual estimates of survival for 18 species. A list of priority species for RAS was developed and promoted to volunteers. The total number of birds ringed (1,096,533) was the highest ever recorded, as well as being the first time the annual total has surpassed 1 million. It was 28% higher than the mean of the previous five years and 17% higher than in 2009. However, the total number of pulli ringed in 2009 (193,554) was only 12% higher than the preceding five-year mean, while that of fully grown birds (902,979) was 32% higher. The recovery total (17,315) was also the highest ever. This is partly due to changes in the way that records of colour-ringed and other specially marked birds are stored, but also reflects the increasing number of birds being ringed by a growing number of ringers. The number of recoveries of foreign-ringed birds (2,427) was higher than the mean of the preceding five years; this figure was influenced by varying response times of different ringing schemes, but was also partly as a result of multiple sightings. Recovery details for 221 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. [ABSTRACT FROM AUTHOR]

In this study, we investigated whether birds could be vectors facilitating long‐distance spread of Phytophthora ramorum in Britain. Migratory bird species associated with the main sporangium‐producing host plants and most likely to pick up P. ramorum spores were considered. Swabs were taken from the flank and “feet” of 1,014 birds over a 12‐month period (April 2011–March 2012) in the west of Britain and subsequently analyzed for the presence of P. ramorum using nested PCR. Ten positive samples from 10 birds were identified: three in Cornwall, one in Devon, three in Gloucestershire, two in north Wales and one in Merseyside. Phytophthora ramorum was detected on samples from four species of thrushes (Redwing Turdus iliacus, Fieldfare T. pilaris, Blackbird T. merula and Song Thrush T. philomelos) and one species of warbler (Chiffchaff Phylloscopus collybita). All birds that tested positive were sampled in late autumn and winter (October–February), when long‐distance movements (over 100 km) would have stopped. The low incidence of P. ramorum found using PCR suggests that the incidence of inoculum, whether viable or not, on birds was low. The apparently low incidence of inoculum on birds suggests migratory passerine birds can carry P. ramorum inoculum on their feathers and “feet,” albeit at low frequency. The dates of positive samples indicate that birds would not have been moving long distances at the time but further work is needed to estimate the extent of their contribution to the spread of P. ramorum in Britain. [ABSTRACT FROM AUTHOR]