At 45 years old, a Fulmar recorded on an uninhabited Scottish island is one of the oldest of its kind ever recorded. The bird’s extraordinary age is a reminder that many seabirds live for a very long time – a trait that can make their populations particularly vulnerable to the impacts of avian influenza (AI). The record is one of many that have just been published in the latest British Trust for Ornithology (BTO) ringing report. Researchers from the British Trust for Ornithology (BTO) were able to work out the Fulmar’s grand old age thanks to a numbered ring that was fitted to its leg by a volunteer bird ringer back in 1975, when the bird was still a fledgling on Eynhallow, Orkney. It was spotted again last year, when the ring number revealed that the bird had reached 45 years, 9 months and 12 days old. Other 1975 births include Microsoft, Jaws and Queen’s Bohemian Rhapsody. Fulmars are one of many seabird species that have been hit hard by the unfolding avian flu outbreak that devastated colonies across Britain and Ireland this summer. Seabirds tend to be long-lived and slow to reproduce – a Fulmar, for instance, might be as old as 12 before it lays its first egg. Even then, early breeding attempts are less likely to be successful. This means it can take a very long time for populations to recover from disease, and that older, more experienced adults play an outsize role in maintaining them. Only time will tell if this particular individual managed to weather the AI storm. Ringing birds lets us work out how old they are, which in turn means we can calculate the rates of individual birds’ survival from one year to the next. It also reveals the places birds move between, their levels of breeding success, and important information about their physical condition. These data are vital if we want to understand the impact of threats like AI and the best ways to target conservation work. Sightings of ringed birds can be submitted to Euring Dr Ellie Leech, head of the British and Irish Ringing Scheme, says, Britain and Ireland’s seabird populations are of global importance, and volunteer bird ringers participating in the BTOs Ringing Scheme play a fundamental role in the monitoring work that underpins conservation efforts. With avian influenza now adding to the significant, existing environmental pressures posed by changes in climate and habitat quality, the dedication of these highly skilled volunteers is more important than it ever has been and we are immensely grateful for their incredible contribution.

Data from the British Trust for Ornithology (BTO) Garden BirdWatch survey, carried out by volunteers across the UK, show a fourfold increase in the number of gardens recording a Hummingbird Hawkmoth, making 2022 a record year. These large, colourful insects are often mistaken for hummingbirds because of the way they hover over flowers and use their long tongues to drink the nectar. You are mostly likely to see a Hummingbird Hawkmoth in the UK during July and August. Last month, 5.2% of Garden BirdWatch gardens recorded a visit from a Hummingbird Hawkmoth, compared to just 1.3% in a typical year, while the proportion rose to 7.5% in southeast England. In Scotland, where the species is much rarer, it was reported from 1.2% of gardens, more than three times the summer average. Hummingbird Hawkmoths are particularly fond of pink and purple flowers like Buddleia, Red Valerian and Vipers Bugloss. Watching these plants on warm, sunny days is the best way to spot one yourself. Just look out for a chunky moth with orange wing patches and black stripes on its body. The influx probably has its origins in the current long spell of warm, southerly winds that carry the moths north from their Mediterranean strongholds. There is also a possibility that rising temperatures mean a growing number are able to overwinter in the UK: in suitable conditions, Hummingbird Hawkmoths will spend the colder months tucked away in thick vegetation, a tree hollow or even a garden shed. While most Hummingbird Hawkmoths recorded in the UK are thought to be visitors from overseas, a number do breed here, laying their bluish-green eggs on plants such as cleavers (sticky-weed) and bedstraws. A single female can produce as many as 200 eggs that grow into stripy green caterpillars up to six centimetres long. Rob Jaques, BTO Garden BirdWatch Supporter Development Officer, said, “The striking appearance and unusual behaviour of the Hummingbird Hawkmoth means the species attracts lots of attention from gardeners and nature lovers alike. Thanks to the citizen scientists who record these and other species in their gardens, BTO Garden BirdWatch is able to track the fortunes of the wildlife on our doorstep and learn how our green spaces can best support biodiversity. As climate change has an ever more obvious impact on the species we see around us, the data our amazing volunteers collect has never been more valuable than it is today.” BTO Garden BirdWatch is free to join and a brilliant way to make a difference for science and conservation.

New research from BTO implicates rising temperatures in the steep decline of the Willow Warbler, one of the UK’s most tuneful harbingers of spring. The study, published in the journal IBIS, shows that Willow Warblers are doing better in Scotland, where temperatures are cooler. Evidence is building to suggest the population in southern Britain is a casualty of recent anthropogenic climate change. BTO researchers used volunteer bird counts and habitat data from the BTO/JNCC/RSPB Breeding Bird Survey to separate the impacts of climate change and habitat change on Willow Warbler and Chiffchaff populations. The analysis revealed that Willow Warbler numbers across the UK fell by 41% between 1994 and 2018, while those of the closely related Chiffchaff grew by 133%. The picture was very different in Scotland, where temperatures are cooler than the UK average. North of the border, Willow Warblers increased by 77% and Chiffchaffs by 244%. During the period studied, the mean breeding season temperature was 12.7°C in England and 10.2°C in Scotland, close to the optimum breeding temperatures for Chiffchaff (13.5°C) and Willow Warbler (11°C), respectively. However, Met Office data show that UK temperatures in the last 30 years have been about 1°C warmer than those during the three preceding decades. Changes like these can have impacts including producing a mismatch between young birds’ food requirements and insect abundance, an overall reduction in food abundance and shifts in habitat suitability. The BBS habitat data showed that woodland and scrub, the preferred habitat for Willow Warblers and Chiffchaffs, increased across the UK, with more habitat improvements in Scotland. However, this study showed that the increases in Scotland were more likely to be linked to climate change than habitat change. Its UK decline means Willow Warbler has been on the Birds of Conservation Concern Amber List since 2002. With global temperatures forecast to keep rising, studies like this demonstrate the importance of long-term monitoring to ensure conservation measures are targeted effectively. More woodland and scrub , for example, would be more likely to be taken up by breeding Willow Warblers if it were concentrated in cooler areas of the UK. Blaise Martay, BTO lead author on the paper, said: ‘We’ve discovered that these two superficially similar warblers have quite different temperature requirements during the breeding season. Climate change means Willow Warblers are now faring worse in warmer parts of the country, something that has implications for future conservation measures, such as habitat creation. The connection we’ve uncovered between temperature and breeding success suggests that conservation interventions for this species should be targeted in cooler parts of the UK. She added, “I’d like to thank all the volunteers who take part in the BTO/JNCC/RSPB Breeding Bird Survey. Their records allow scientists like me to undertake analyses like this one and help us understand the pressures birds face as a result of climate change.’ Read the full paper for free on Wiley.

The change in behaviour is one of the most remarkable signs yet of the warming world being caused by climate change, according to the BTO’s Chief Executive, Juliet Vickery, “It is indeed remarkable. We haven’t got to go back too far to remember winters when it would have been impossible for Swallows to survive the freezing temperatures, but as our winters get milder it is something we may see more and more.” Swallows head south at the end of summer because the European winter is too cold for the flying insects on which they feed. And for thousands of years, the return of the bird from its winter quarters in Africa has been one of the key signs of the coming of spring all across Europe. It is greeted with delight and celebrated in the folklore of many countries. A famous Greek vase from 500 BC shows three men looking up at a returning swallow with the caption Spring already! But with the run of mild winters in recent years, a small number of swallows have been able to attempt to spend the winter months here. This year – 2022 – the BTO’s BirdTrack survey of birdwatchers’ regular observations has received almost a hundred reports of up to 12 individual swallows between January 1 and February 1. Most have been seen in the warmer south and south-west of Britain, and also in Ireland. Professor James Pearce-Higgins, the BTO’s Director of Science, said, “To suggest that our winters would be warm enough for swallows to survive would have been unthinkable a few decades ago, but the evidence that our climate is changing is building year by year.” Although the return of the Swallows has been celebrated for thousands of years, until the 20th century it was not known where they went, when they disappeared in the autumn. Some people, even some scientists, thought that they hibernated in the bottom of ponds. Their true destination was only revealed in the early 20th century with the introduction of bird ringing. In December 1912, a Swallow was caught on a farm in Natal, South Africa, bearing a ring which had been placed on its leg 18 months earlier by John Masefield, a solicitor and amateur naturalist, in the porch of his house at Cheadle in Staffordshire. This proved that a bird not much bigger than a matchbox could undertake an immense annual journey that included crossing the Sahara desert. The Swallow is not the only bird being affected by climate change. The BTO’s recent report Climate Change and the UK’s Birds indicated that a quarter of British breeding species might be negatively affected – with one of the British public’s favourite birds, the Puffin, likely to disappear completely. Visit BirdTrack for information about how you can submit your bird observations.

Thanks to the efforts of nearly 10,000 'citizen scientists' we now have a much greater understanding of the UK's breeding Tawny Owls, together with much-needed information on their calling behaviour, that will help future surveys of the species. The results of this study have just been published in the journal Bird Study. Despite being reasonably common, widespread, and easily identifiable from its vocal behaviour, we know surprisingly little about the changing fortunes of the UK's breeding Tawny Owl population. There is evidence for an ongoing but shallow long-term decline in the population since the mid-1980s, but this evidence comes from studies that involve daytime surveys by volunteers. Better information is likely to come from dedicated surveys, carried out at night during the Tawny Owl’s breeding season, when territorial vocal activity is at its peak. Such dedicated surveys typically rely on the use of call playback to elicit responses from territorial birds, a labour-intensive method that limits survey coverage. An alternative approach has been tested using nearly 10,000 volunteer 'citizen scientists' and the results are extremely encouraging. The BTO Tawny Owl Calling Survey set out to establish the factors that influenced Tawny Owl calling behaviour (such as weather conditions and local habitat) and to determine whether the approach could reveal changes in Tawny Owl populations over time. The BTO Tawny Owl Calling Survey was carried out over two separate survey periods (October to March in 2005/06 and 2018/19) and had a particular focus on the impact of urbanisation. Volunteers carried out surveys across each winter period, avoiding evenings that were wet, windy or had poor visibility. They were asked to record whether they heard Tawny Owls calling during the survey period, and to specify the types of Tawny Owl calls heard. The volunteers also collected data on the amount of cloud cover, which was used alongside environmental data from other sources to identify factors that might influence calling behaviour. Some 9,452 volunteers took part in the survey in 2018/19 and 3,465 took part in 2005/06, collectively covering 9,567 sites. Overall, Tawny Owls were reported at least once from 86.8% of sites in 2005/06 and 84.3% of sites in 2018/19, suggesting that Tawny Owl populations have been largely stable over this period. Dr Hugh Hanmer, lead researcher on the project, says, “The data generated by our volunteers inform our understanding of Tawny Owl calling behaviour and of the types of sites where they occur. Importantly, these data can be used to shape the design of future surveys. For example, the results of the volunteers' weekly efforts imply that five or six survey visits would be needed within a survey season to determine with confidence whether Tawny Owls are present at a site or not.” Surveys carried out in the autumn and early winter were more likely to detect an owl at occupied sites than those carried out in the middle of winter, but there was an upturn in activity in early spring. Such patterns almost certainly reflect the changing territorial behaviour over this period, with Tawny Owls likely to be more vocal in the autumn as established adults respond to the settlement of dispersing juveniles, and increase their vocal activity again in spring when breeding begins in earnest. Tawny Owls were less vocal on cloudy nights and when it was raining, but more active on nights when the moon was fuller. The two strongest factors influencing whether or not Tawny Owls were present at a site were the amount of broadleaf woodland cover locally and the amount of artificial light at night, the latter a measure of the degree of urbanisation. Occupancy increased with woodland cover, but declined as the degree of urbanisation (and artificial light at night) increased. Michelle Reeve, BTO Garden BirdWatch Manager (and whose volunteers played an important role in the study), says, “The study demonstrates the tremendous value in being able to use citizen scientists to capture data on Tawny Owls and engage both new and existing volunteers with active participation in science. This is a bird that many of us will know; even if we have never seen one its hooting call is likely to be familiar.”