Birds of Conservation Concern

From British Trust for Ornithology, British Ornithologists’ Union and British Birds

The fifth edition of Birds of Conservation Concern (BoCC) has been published. Undertaken every five years, BoCC covers the population status of birds regularly found in the UK, Channel Islands and the Isle of Man to provide an up-to-date assessment of conservation priorities. This fifth review has assessed a total of 246 species and placed them onto one of three lists, red, amber or green, according to their level of conservation concern (see RSPB for explanation of categories). 52 species are red-listed (up from 40 at the previous review), 126 are amber-listed (previously 121) and 68 are green-listed (down from 86).

Seven quantitative criteria have been used to assess the population status of each species and to place it on the red, amber or green list: global conservation status, recent decline, historical decline, European conservation status, rare breeders, localised species and international importance.

Most of the data for these assessments are based on bird surveys undertaken by volunteers, such as those run by the British Trust for Ornithology.

A parallel exercise was undertaken to assess the extinction risk of all bird species for Great Britain (the geographical area at which all other taxa are assessed) using the criteria and protocols established globally by the International Union for the Conservation of Nature (IUCN). This resulted in the assessment of 235 regularly occurring species (breeding or wintering or both), the total number assessed differing slightly from BOCC5 due to different rules on the inclusion of scarce breeders and colonisation patterns. The results of this second IUCN assessment (IUCN2) are provided in the same paper as BOCC5.

How the lists are decided

The BOCC assessment is based on the most up-to-date evidence available. Criteria include conservation status at global and European levels and, within the UK: historical decline, trends in population and range, rarity, localised distribution and international importance. Golden oriole (previously Red-listed but which has not bred in the UK since 2009) now joins a Black List of eight other species now considered to have ceased breeding in the UK (including serin, Temminck’s stint and the once widespread wryneck). Four new species that have more recently become sufficiently established, as well as yellow-browed warbler (no longer considered a scarce migrant), were assessed by BOCC5 – little bittern, cattle egret, great white egret and black-winged stilt – and all went onto the Amber list due to criteria related to scarcity and localisation.

The IUCN assessment process uses the same underlying data on population trends and population size but the time periods over which change is assessed differs and is linked to generation length and also population size. With their focus on extinction risk, the IUCN assessments also consider the potential for populations in Great Britain to be rescued by immigration from increasing populations in surrounding geographical areas.

The growing Red List

This update shows that the UK’s bird species are increasingly at risk, with the Red List growing from 67 to 70. By contrast, the first Red List, published in 1996, had only 36 species. Eleven species have been Red-listed for the first time in 2021, six due to worsening declines in breeding populations (greenfinch, swift, house martin, ptarmigan, purple sandpiper and Montagu’s harrier), four due to worsening declines in non-breeding wintering populations (Bewick’s  swan, goldeneye, smew and dunlin) and one (Leach’s storm-petrel) because it is assessed according to IUCN criteria as Globally Vulnerable, and due to evidence of severe declines since 2000 based on new surveys on St Kilda, which holds more than 90% of the UK’s populations. The evidence for the changes in the other species come from the UK’s key monitoring schemes such as BTO/JNCC/RSPB Breeding Bird Survey (BBS) for terrestrial birds, the BTO/RSPB/JNCC Wetland Bird Survey (WeBS) for wintering populations and the Rare Breeding Bird Panel (RBBP) for scarce breeding species such as purple sandpiper.

From green to red

Two species moved directly from the Green to Red List: greenfinch and ptarmigan. Increasingly severe declines in greenfinch numbers have been reported in BBS reports for more than a decade, and the initial regional pattern of declines was associated with outbreaks of the disease Trichomonosis. This disease of the digestive tract is widespread in greenfinch populations across Europe and may also be starting to affect other species such as collared dove, sparrowhawk and chaffinch.

The IUCN assessment resulted in 108 (46%) of regularly occurring species being assessed as threatened with extinction in Great Britain, meaning that their population status was classed as Critically Endangered, Endangered, or Vulnerable, as opposed to Near Threatened or of Least Concern. Of those 108 species, 21 were considered Critically Endangered, 41 Endangered and 46 Vulnerable. There is considerable overlap between the lists but unlike the Red List in BOCC5, IUCN2 highlights the vulnerability of some stable but small and hence vulnerable populations as well as declines in species over much shorter recent time periods, as seen for chaffinch and swallow.

What kinds of birds are in the most trouble?

How does the Red List break down across habitats or taxonomic groupings? Unlike previous BOCC assessments, where there was a clearer pattern of influx to the Red List, with upland and woodland species joining the already listed farmland species, this update is more of a mixed bag. However, the worsening status of Afro-Palearctic migrants continues with two aerial insectivores – swift and house martin – joining other migrants such as cuckoo and nightingale on the Red List. Although deteriorating conditions on the wintering grounds and on stopover sites are likely factors, the reliance of many long-distance migrants on insects and other invertebrates suggests that declines in those could also play a role.

The other group joining the Red List also encompasses migrants, in this case, wintering wildfowl and waders that breed at higher latitudes and to the east, but winter in the UK. Climate change and milder winters in regions such as the Baltic Sea have resulted in many of these species being less likely to migrate as far west and south as the UK, in a pattern termed ‘short-stopping’. This is likely the case for Red List newcomers dunlin and smew, but can be further complicated by broader declines in populations, as is known for the Eastern flyway populations of Bewick’s swan.

Can conservation action work?

There is also better news. In addition to white-tailed eagle, which no longer qualifies for ‘historical decline’ thanks to further recovery of the breeding population and intense conservation efforts, five previously Red-listed species (pied flycatcher, song thrush, black redstart, grey wagtail and redwing) have shown modest but sufficient improvements in breeding population status to have moved from Red to Amber. Red grouse, mute swan and kingfisher also move from the Amber to Green. Overall, the Amber List has increased from 96 in BOCC4 to 103 in BOCC5, this difference reflecting both negative (moves to the Red List) and positive changes (moves to the Green List). The Green list, now 72 species long, includes a range of common garden species such as blue tit, blackbird and robin, and saw a net loss of nine species since BOCC4.

The full lists are available in the Birds of Conservation Concern 5 – Summary leaflet here and the full paper The status of our bird populations: the fifth Birds of Conservation Concern in the United Kingdom, Channel Islands and Isle of Man and second IUCN Red List assessment of extinction risk for Great Britain here

Climate change and the UK’s birds

From BirdGuides

A newly published study from the British Trust for Ornithology indicates that many of the UK’s seabird populations including that of the Atlantic puffin could plunge by as much as 90% by 2050 because of changes in the marine environment caused by rising temperatures, if global warming is not checked.

“This could represent a loss of over a million birds,” warned the BTO’s CEO, Professor Juliet Vickery. 

Increasing water temperatures are having a negative impact on sandeel numbers in British waters, the small fish which are the puffin’s main prey species – meaning that the breeding productivity of the puffins themselves is being adversely affected.

According to the BTO report, this is also affecting other seabirds, such as kittiwake; in all, 11 of our 20 breeding seabird species are regarded as being highly vulnerable to future climate change. The seabird numbers that the UK holds are internationally important.

Professor Vickery added: “If we are to hold onto our important bird populations then we need governments to make the right decisions for nature and the climate after COP26, and to invest in real action towards meeting these commitments. We will also need to continue to monitor the results of our actions – to evaluate what works and what doesn’t.”

Dr James Pearce-Higgins, Director of Science at BTO and author of the report, explained: “This new analysis reveals that, overall, one in five UK bird species will be affected by climate change. It is not just our seabirds that will be impacted; we will lose some of our best-loved summer visitors too. Once familiar migrants, such as common cuckoo and spotted flycatcher, have already seen their breeding populations more than halved during the last 25 years.”

Pearce-Higgins added: “Changing conditions here in the UK may have some impact, but the effects of changing weather patterns on the wintering grounds in Africa and along the migration routes used by these migrant birds may also be important. Projecting the future fortunes of these and other migrant birds is challenging given their complicated lives that cross continents. Securing their future will require international collaboration right along their flyway.”

Importantly, the report highlights those species that could be impacted by attempts to mitigate climate change, such as increased development of offshore renewables and widespread tree planting on upland habitats. Knowledge of bird numbers and distributions, gathered by BTO’s network of 60,000 citizen scientists, can help to inform how and where these approaches can be used in ways that minimise any potentially damaging impacts on declining species. We need to maintain our efforts to safeguard our seabirds, like the puffins, and other birds to ensure that they get as much support as we can give them.

The full report, Climate Change and the UK’s Birds, can be read here.

Garden bird feeders are boosting blue tit numbers – but leaving other species hungry

From The Conversation

We’ve filled feeders with seeds and nuts since many of us were children and loved seeing which birds arrive. And, we’re not alone – around half of all UK households do the same nowadays, spending £250 million on 150,000 tonnes of bird food each year. That’s enough to feed three times the breeding populations of the ten commonest garden species if they ate nothing else all year, with one feeder for every nine birds that use them.

Have you ever wondered how all of that additional food might be affecting wild birds? How much has our generosity changed their natural diet, and what of the bird species we don’t see visiting garden feeders?

If you live in the UK and the Channel Islands, one garden visitor you’re probably used to seeing is the blue tit. Blue tits are small, fast and often feed high in trees on tiny insects. Seeing exactly what they eat is tough. But with new molecular technology, it has been possible to test blue tit faeces from 39 woodlands across Scotland – some close to houses, some on remote mountainsides and some by the sea – and gain a fascinating insight into their average diet.

What was found, came as a surprise. A small moth caterpillar (Argyresthia goedartella) that lives on birch trees was their most common natural prey item, present in a third of the faeces sampled. But among hundreds of species of insect prey, there was also garden bird food – and lots of it.

Peanuts were present in half of all the faeces – the most common food item for Scottish blue tits – and sunflower seeds in a fifth. And the birds weren’t just popping next door to find these garden treats. Some were travelling as much as 1.4km from remote areas to nibble on their favourite garden snacks. Clearly this has become part of their staple diet.

A blue tit bonanza

Eating the food we provide gives blue tits more energy to lay eggs – five days earlier than blue tits that don’t. These earlier breeders are likely to raise more healthy chicks. Eating bird food was also linked to a nearly four-fold increase in the proportion of adults available to breed in a given area. Where there used to be one pair of blue tits nesting, garden bird feeders nearby meant there was now likely to be almost four pairs sharing the same space.

Other woodland species such as great tits, nuthatches and great spotted woodpeckers that enjoy garden bird food are doing very well too. Their UK populations have increased on average over the last 25 years that bird feeding has really taken off.

All this feeding might be giving these species an unfair advantage. These species have natural competitors in the woods that aren’t using bird feeders as much or at all, either because they’re shy or because they’re bullied by more dominant species, or because they don’t like the food people provide. These species include the marsh tit, willow tit, pied flycatcher, wood warbler and lesser spotted woodpecker. What’s happening to them is, sadly, not such good news.

How to help all woodland birds

On average, woodland birds that don’t use garden bird feeders have declined over the past 25 years, some to the point where they have almost disappeared from the UK countryside. Nobody knows exactly why, and while this may be partly due to their habitat fragmenting and the climate warming, garden bird-feeding may have also played a role.

Due to people feeding them, there are now more dominant blue and great tits in the woods than 25 years ago, eating more of the limited natural food and evicting other species from their nests. There are also more great spotted woodpeckers and squirrels, which eat the chicks of some birds. Perhaps an extra 700,000 pairs of very healthy and dominant great tits in woodlands is too much for the UK’s remaining 2,000 pairs of shy and subordinate willow tits.

While results suggest there’s a link between how much woodland birds visit feeders and their population trends, they don’t show a direct cause, so we shouldn’t panic yet. While scientists study this problem, responsible bird lovers can help.

Consider contributing to the garden bird surveys organised by the RSPB, British Trust for Ornithology and Action for Wildlife Jersey/Birds On The Edge to help scientists keep track of where birds are, in what numbers and what they’re doing. If you’re lucky enough to live where rare woodland bird species can still be found, consider providing less bird food to common species and cleaning your feeders regularly.

Meanwhile, there are more natural ways to encourage wild birds into your garden. Planting native shrubs and trees like rowan, hawthorn, silver birch, spindle and guelder rose is one option. They are all beautiful year-round, fairly small and provide excellent habitats for wild birds. Other ideas include mowing lawns less often and digging ponds.

As some rare species nest close to the ground, please keep dogs on leads while walking in woodlands during the spring too. But most importantly, keep enjoying these beautiful birds – in all their miraculous diversity.

Further reading:

Faecal metabarcoding reveals pervasive long-distance impacts of garden bird feeding

A national scale inventory of resource provision for biodiversity within domestic gardens

Wild bird feeding in an urban area: intensity, economics and numbers of individuals supported

 

 

The State of the UK’s Birds 2020

From BTO

The State of UK’s Birds reports have provided an annual overview of the status of breeding and non-breeding bird species in the UK and its Overseas Territories since 1999. This year’s report highlights the continuing poor fortunes of the UK’s woodland birds.

SUKB collates data from annual, periodic and one-off surveys and monitoring studies of birds, such as the Breeding Bird Survey (BBS), Rare Breeding Birds Panel (RBBP), the Wetland Bird Survey (WeBS), Seabird Monitoring Programme (SMP) and Goose and Swan Monitoring Programme (GSMP). In addition, the 2020 report also includes results from the Nest Record Scheme, Constant Effort Sites (CES) Scheme and Re-trapping Adults for Survival (RAS) Scheme, the latter two schemes collecting demographic information through the efforts of bird ringers.

The report takes information from these and other schemes, research and surveys and delivers information at a country-specific scale, as well as providing an overview for the UK as a whole.

Volunteers play an essential role in bird monitoring in the UK, by donating their time, energy and expertise. The data they collect are vital for conservation, tracking changes in populations and supporting policy development. This year, many monitoring schemes have been adversely affected by the global COVID-19 pandemic and we want to say a special thank you to all of our volunteers for their continued support through this difficult time. Their skill, effort and dedication deserve huge recognition.

Woodland species

This year’s report highlights the continuing poor fortunes of the UK’s woodland birds. The UK Wild Bird Populations Indicator for woodland species show a long-term decline of 27% since the early 1970s, with declines of 7% evident over just the last five years. More worryingly, when looking at individual trends within the report, some specialist woodland birds have declined dramatically, including willow tit with a 94% decline since 1970 as illustrated by the joint Common Birds Census / Breeding Bird Survey UK-wide trend.

After worrying declines in breeding tawny owl populations were flagged-up by the Breeding Bird Survey, BTO launched targeted survey work on this species during 2018 and 2019. SUKB reports on some of the results from this research, which revealed a decline in site occupancy from 65% in 2005 to 53% in 2018/19. The BTO work has also sought to understand some of the reasons for this change in fortunes.

Results at different scales

Data from many of the surveys covered in SUKB also feed into European-wide schemes and the SUKB report goes from celebrating the publication of the latest European Breeding Bird Atlas, through to finer-scale country-specific results and research. Not bad for an 80-page report!

Country-specific headlines include increases in house sparrow populations in Wales, where work is also taking place to address the pronounced decline in curlew numbers. In Scotland, the fragile status of corncrake is highlighted, alongside increases in farmland species such as tree sparrow and yellowhammer. The Northern Ireland pages look into changing fortunes of seabirds and explore how proposed marine Special Protection Areas may be used to tackling the observed decline. The Northern Ireland pages also examine declines in wintering geese, such as light-bellied brent goose. Finally, over to England and promising results for stone curlew conservation work, as well as reporting back on the English Winter Bird Survey for which 1,485 sites were surveyed by volunteers to help us understand the value of agri-environment options.

As in previous reports, we hear about species from 14 UK Overseas Territories and three Crown Dependencies – including black-browed albatross, St Helena plover and South Georgia pipit, about the Gough Island Restoration Programme, and discover that 69 species in the Overseas Territories and Crown Dependencies are now Globally Threatened.

Closer to home, 25 years of BTO Garden BirdWatch is also celebrated, with goldfinch now the 8th most commonly recorded garden bird, up from 20th back in 1995.

Volunteers

There is a common theme in this report: volunteers. The sheer enormity of their contributions to bird monitoring as a whole is evident throughout this report. Most of the surveys and schemes covered here are only possible thanks to the dedication and skills of the thousands of volunteers who give up their time to help monitor birds and in turn, inform conservation action. Thank you.

Who produces this report?

SUKB 2020 is produced by a coalition of three NGOs: the Royal Society for the Protection of Birds (RSPB), the British Trust for Ornithology (BTO) and the Wildfowl & Wetlands Trust (WWT), together with the UK’s statutory nature conservation bodies: Department of Agriculture, Environment and Rural Affairs, Northern Ireland (DAERA), the Joint Nature Conservation Committee (JNCC), Natural England (NE), Natural Resources Wales (NRW) and NatureScot.

Download The State of the UK’s Birds 2020 here