ABSTRACT Here we present a simple setup to picture birds in the hand with a smartphone. By controlling the background and light conditions, and using a remote shutter, it proved possible to take standardised high-quality pictures of birds and details of birds in the hand in field conditions. Results were comparable to pictures taken by a professional SLR-camera photo-studio setup in that even vague moult limits could be discerned. The simple and affordable photo-system setup we describe allows any ringer with a smartphone to document captures with good pictures. This opens up a wide range of possibilities for documentation, information exchange and training on the basis of standardised high-quality pictures.

ABSTRACT We present 19 months of continuous monitored flight in a combined data set collected through a multi-sensor data logger attached to a single subadult Common Swift. Similarities in the migration routes, stopover locations visited and flight altitudes between subadult and adult flight patterns, in both migration and overall non-breeding moonlight-driven flight strategy, may be the result of a genetically fixed trait or a learned experience during the relatively long subadult stage of a long-lived species. Deviations from moonlight-driven flight patterns during the breeding season highlight a potential response to anthropogenic skyglow. Our findings refine research avenues with respect to the behaviour of subadult Swifts in relation to migration strategies and the potential influence of skyglow on foraging.

ABSTRACT The breeding success of Great Tits and Blue Tits using nest boxes at a 12.5-ha site in southwest Scotland has been monitored for 11 years (2014–24). Data collected includes date of first egg laying, clutch size, brood size and brood mass at 11 days old, and fledging success. A short burst of exceedingly heavy rain on a single afternoon in May 2024 resulted in extensive breeding failure: in 2024 there was 49% survival to fledging in Great Tits (n = 7), compared to 74% over the preceding 10 years (n = 40), and 34% in Blue Tits (n = 9) compared to 73% over the preceding 10 years (n = 38), with surviving broods having very low biomass.

ABSTRACT This is the 82nd annual report of the British Trust for Ornithology’s Ringing Scheme, incorporating the report of the Nest Record Scheme and covering work carried out and data processed in 2018. We reviewed the literature on tracking devices to assess the impact of their use on individual birds. More than 3400 studies were identified, the first dating back to the early 1960s. The ecological questions being studied varied, with migration being the most common study subject. The frequency of effects was significantly related to attachment type and the likelihood of adverse effects was related to device weight. The proportion of studies reporting adverse effects has declined over time and the research highlighted the need for systematic documentation of potential effects. NRS and CES data were used in a collaborative study which investigated mismatches between the timing of breeding for 21 British songbirds and the availability of food for their chicks. Results indicate that birds did breed later in warmer springs relative to the timing of spring; however, this did not have a significant impact on long-term breeding success. In 2018, 135 CE sites submitted data. Long-term (1984–2017) declines in abundance were observed in six migrant, one partial migrant and three resident species while long-term increases in abundance continue to be recorded in two short-distance migrants and four resident species. Seven species are exhibiting significant long-term declines in productivity; only two species, Reed Warbler Acrocephalus scirpaceus and Chaffinch Fringilla coelebs, are exhibiting a significant long-term increase in productivity. Long-term trends in survival indicate increases for 12 species and declines for eight. Compared to the five-year mean (2013–17), the abundance of 14 species decreased significantly in 2018 with five species being recorded in lower numbers than in any previous year since CES monitoring began. No significant increases in abundance were recorded. Productivity increased significantly for six migrant and four resident species in 2018 and decreased for only two species (both residents). Significant declines in survival rates were observed in 10 species in 2018 compared to the five-year mean. The number of Retrapping Adults for Survival submissions fell slightly in 2018 to 190; eight projects ran for the first time. In total, 58 species were monitored, with Pied Flycatcher Ficedula hypoleuca (23 projects), House Sparrow Passer domesticus (18), Starling Sturnus vulgaris (17), Sand Martin Riparia riparia (13) and Reed Warbler (10) the most-studied species. A total of 982 858 birds were ringed during the year, comprising 170 619 nestlings, 465 610 first-year birds, 319 955 adults (birds in their second calendar year or older) and 26 674 birds whose age could not be determined. In addition, there were 236 314 recaptures of ringed birds at or near the ringing site. In total, 54 324 recoveries (birds found dead, recaptured or resighted at least 5 km from the place of ringing) of BTO-ringed birds were reported in 2018. The Appendix highlights a selection of recoveries that have extended our knowledge of movements, as well as longevity records established during the year. A total of 38 269 NRS submissions were received in 2018, the lowest total since 2009. Mean laying dates for four species were significantly earlier than the five-year mean (2013–17) with eight of the 52 species analysed laying significantly later. Eight species displayed a significant increase in breeding success (fledglings per breeding attempt) in 2018 compared to the five-year mean, with one decreasing significantly. Permits or licences to disturb breeding birds on Schedule 1 of the Wildlife and Countryside Act 1981 (as amended), were prepared and issued to 502 ringers and nest recorders in 2018. During 2018, the use of special methods was authorised for 557 marking projects, 66 trapping projects and 52 sampling projects.

ABSTRACTResearch on wild birds requires suitable techniques for the capture of target species. In this study, we tested a new technique for the capture of birds for tagging with satellite platform transmitters or GPS loggers. This technique, referred to as ‘tele-anaesthesia’, was the most appropriate tool to obtain the data needed for our studies. Seven wild White Storks Ciconia ciconia were captured using a hypodermic CO2 gas injection rifle, projecting syringes containing Xylazine. This is the first study to test this method for catching a large free-flying wild bird species under field conditions. Although the method will require appropriate licensing and veterinary supervision, it facilitates the safe and efficient capture of targeted individuals.

ABSTRACTArctic Terns Sterna paradisaea have a record long migration between their breeding grounds in the Arctic and wintering areas in the Antarctic. Nevertheless, return dates to north Norway were remarkably constant over a 35-year period (1981–2015), with Arctic Terns arriving in Troms within a 13-day time window in mid to late May. Since 1993, arrival dates have advanced by about four days. No relationships were found between arrival dates and large-scale weather proxies such as the North Atlantic Oscillation or sea temperatures, but when terns were approaching Troms, headwinds tended to delay arrivals whereas tailwinds advanced them.

The moult pattern of the Graceful Prinia Prinia gracilis, a resident cisticolid warbler of the Middle East region of the Western Palaearctic, is poorly known. Characterising moult strategies in the avian life cycle is important for understanding population processes and dynamics and, therefore, we have analysed the timing, sequence, extent and duration of post-juvenile moult of Graceful Prinia in Israel. The extent of post-juvenile moult was either complete or partial (but extensive), depending on the dates of hatching and the start of moult. Compared to most European passerines, the long breeding period (February–November) in this region allows a relatively long moult period (79.3 ± 4.7 days) for this resident species, which facilitates considerable variability in the extent of post-juvenile moult.

Moult of Spectacled Warbler Sylvia conspicillata was studied in central Spain. Between April 2010 and August 2013, 136 adult birds were captured and 43 of these were moulting. Of the moulting birds, 30% had atypical moult of secondary feathers, indicative of suspended moult and the retention of old feathers.

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.

In this paper we analyse and compare biometric data of Twite Carduelis flavirostris from Ireland, England and Scotland (Orkney). Data were separated by season (breeding or winter) to account for potential mingling of populations during the winter. The mean wing length of wintering male Twites, but not females, differed significantly between the countries. In the winter, for both sexes, Scottish Twites were significantly heavier than Irish and English ones, which did not differ from one another. Breeding Irish Twites were heavier than breeding English Twites, in both sexes. Males in all countries had longer wings than females. Males were heavier than females in Ireland and England but sexes were of equal mass in Scotland. These results raise questions about the structure, origins and behaviour of wintering Twite populations. Some of the difficulties of ageing and sexing Twites are discussed.