Bird ringing and nest recording in Britain and Ireland in 2014

Abstract

This is the 78th 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 2014. Many species have shifted their range towards the Earth's poles in response to global temperature increases. Data from four European Constant Effort Sites (CES) ringing schemes were examined to determine the impact of large-scale temperature variations on productivity in a group of seven migratory bird species to determine the potential for future range changes. Increased productivity at northern sites was apparent only in Reed Warbler Acrocephalus scirpaceus, although there was evidence of local adaptation in six species, suggesting that the rate of northward range shift may be constrained by adaptation to local climatic conditions. A study on the role of carry-over effects in Redstart Phoenicurus phoenicurus, Spotted Flycatcher Muscicapa striata and Wood Warbler Phylloscopus sibilatrix found that carry-over effects from passage regions impacted on the timing of breeding more strongly than climate on the breeding grounds and that warmer conditions in the breeding area were not associated with reduced productivity. Work on the impact of environmental variables on annual population changes found that, over 40 years, the strongest impact on migrants was rainfall in the Sahel. Over 25 years, positive population changes in response to wetter winters were found for 12 of 16 species studied. Data were submitted for 132 CE sites in 2014. Long-term (1984–2013) population trends derived from the CES data have changed little in the past year. The abundance of five migrant species and five resident species decreased significantly in 2014 compared to the five-year mean (2009–13). The abundance of five of these species (Willow Warbler Phylloscopus trochilus, Sedge Warbler Acrocephalus schoenobaenus, Blackbird Turdus merula, Chaffinch Fringilla coelebs and Greenfinch Chloris chloris) was at its lowest since CES monitoring began. There were significant increases in abundance for three species. Productivity decreased significantly in Willow Tit Poecile montana compared to the five-year mean (2009–13), but there were significant increases for eleven species (seven residents and four migrants),with productivity for Reed Warbler, Blackbird and Bullfinch Pyrrhula pyrrhula at its highest since CES began. There were only two significant changes in survival in 2014. A total of 176 Retrapping Adults for Survival (RAS) projects were active in 2014, the highest total ever, with 22 new projects starting, 17 of which involved RAS target species. Projects were carried out on Tawny Owl Strix aluco and Swift Apus apus for the first time. The total number of birds ringed in 2014 exceeded one million for the third time (1,047,026) and comprised 520,477 first-year birds, 303,086 adults (birds in their second calendar year or older), 29,799 unaged birds and 193,664 nestlings. In addition, there were 226,303 recaptures of ringed birds at or near the ringing site. In total, 28,187 recoveries of BTO-ringed birds were reported for 2014. A selection of recoveries that have extended our knowledge of movements is presented, as well as longevity records established during the year. The numbers of birds recovered between 2010 and 2013 have been revised as data submitted as retraps have been examined and some have been reclassified as recoveries. For the fifth year running, annual totals of nest records surpassed 40,000, reaching 46,382. Mean laying dates for 55 species were significantly earlier than the five-year mean (2009–13) with 19 species laying significantly later than the five-year mean. Breeding success (fledglings per breeding attempt) increased significantly for 14 species, with none showing a decrease. Nearly 600 permits/licences to disturb breeding birds on Schedule 1 of the Wildlife and Countryside Act (1981), were prepared/issued in 2014, a small increase from 2013. The use of special methods was authorised for 398 marking projects and 47 trapping projects in 2014, 12% fewer than in 2013.