BTO - British Trust for Ornithology - Population dynamics

The State of the UK's Birds 2020

WSKELLORN — Fri, 11 Dec 2020 13:35:42 +0000

The Cuckoo cohort of 2024 takes flight!

Burns, F., Eaton, M.A., Balmer, D.E., Banks, A., Caldow, R., Donelan, J.L., Douse, A., Duigan, C., Foster, S., Frost, T., Grice, P.V., Hall, C., Hanmer, H.J., Harris, S.J., Johnstone, I., Lindley, P., McCulloch, N., Noble, D.G., Risely, K., Robinson, R.A. & Wotton, S. Our volunteers: the beating heart of BTO data

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. Sarah Harris, BBS National Organiser

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.

Mixed fortunes for UK’s herons and egrets

VIOLA.ROSS-SMITH — Fri, 02 Feb 2024 09:54:32 +0000

2024-05 02 Feb 2024

Surveys show colonising egrets and Spoonbills continuing to increase in many parts of the UK, while breeding Grey Herons seem slow in bouncing back following recent declines.

The British Trust for Ornithology (BTO) is marking World Wetlands Day (2 February) with the latest findings from its long-running Heronries Census. First launched back in 1928, the study set out to monitor and estimate the numbers of Grey Herons nesting in Britain. In recent years, the species covered in the census has grown as egrets and other waterbirds formerly restricted to the continent have colonised the UK’s wetlands, considered by many to be a direct result of climate change.

Little Egrets first nested in the UK in 1996 and over the past couple of decades they have been joined by Great White Egrets, Cattle Egrets and Spoonbills. Another bird covered by the census is the Cormorant, which has seen a change in nesting behaviour, with some birds now breeding inland in trees as opposed to on traditional coastal cliffs.

Grey Herons have shown ‘boom and bust’ population rises and dips since the census began almost a century ago, with temporary declines often associated with severe winters. However, the current reduction in breeding numbers is showing little sign of recovery and researchers are concerned that this familiar bird may be heading for the Birds of Conservation Concern Amber List.

Ian Woodward, Research Ecologist at the BTO said “This ongoing survey helps us monitor the overall well-being of nesting heron species across the UK. Thanks to the wealth of information gathered by our dedicated volunteers we can see just how these birds are responding both positively and negatively to changes in the environment.”

He continued “It also goes to show just how important the UK’s wetlands are as essential habitats for many of our resident species as well as those already colonising from the continent, such as Spoonbills, and those showing signs of doing so, such as Glossy Ibis.”

The Heronries Census is a valuable tool in the BTO’s research into the changes occurring within populations of wetland birds and more volunteers are being sought to help fill in some of the missing gaps.

Ian added “Many birdwatchers may be aware of new or small nesting colonies that haven’t yet been recorded by the census, and these could be vital in our understanding of how these species are adapting to change, or colonising new areas. The more information we can gather, the better we will understand just how our nesting herons and egrets are faring in an ever-changing landscape.”

Publication details

For further information about the BTO Heronries Census see here.

Images

Images are available for use alongside this News Release. These can be downloaded from this link for which you will need to enter the password 202405heron. Alternatively, please contact press [at] bto.org quoting reference 2024-05.

Seabird abundances projected to decline in response to climate change in Britain and Ireland

VIOLA.ROSS-SMITH — Tue, 05 Dec 2023 11:57:57 +0000

The Cuckoo cohort of 2024 takes flight!

More Details

Davies, J.G., Humphreys, E.M., Evans, T., Howells, R., O’Hara-Murray, R. & Pearce-Higgins, J.W. Marine Ecology Progress Series 10.3354/meps14462

Estimating species’ vulnerability to climate change is a key challenge in conservation. Many seabird species are particularly sensitive to negative effects of warming and are thus threatened by climate change. We projected seabird abundance in 2050 in Britain and Ireland, an internationally-important region for seabirds, under climate change scenario RCP8.5. Our projections were based on fitted relationships between abundance and both climatic (air temperature, precipitation) and oceanographic (sea surface temperature, potential energy anomaly) variables, estimated using a Bayesian hurdle model with spatial random effects. The most consistent responses to environmental variables were negative relationships between species presence or abundance and breeding season maximum terrestrial air temperature. Although data and modelling issues meant that future projections could be made for only 15 of the 25 species and with low predictive power for spatial abundance, predictive power was high for spatial presence and moderate for temporal abundance change. Projections suggest that seabirds will generally fare poorly under climate change in Britain & Ireland, with 10 species projected to decline in abundance by 2050. Variable model fit and projection uncertainty limited confidence, which was generally greater for declines than for increases. Fulmar, puffin and Arctic tern were each projected to decline by over 70% with higher confidence. For a few species, colonisation of new areas may reduce projected losses, but this is potentially limited by suitable habitat. Projected abundance change was more negative for marine specialists than for generalists. Our findings highlight the vulnerability and conservation needs of seabirds in a changing climate.

This paper was supported by funding from gifts in Wills to the BTO, for which the authors are extremely grateful. This paper is an output from the Marine Protected Areas Management and Monitoring (MarPAMM) project; the authors thank the project steering group for useful feedback at all stages of the development of the study and Naomi Wilson for the financial administration of the project on behalf of Agri-Food and Biosciences Institute (AFBI). This project has been supported by the EU’s INTERREG VA Programme, managed by the Special EU Programmes Body (SEUPB).

About WinGS

WEBSITEEDITOR — Tue, 01 Aug 2023 16:27:18 +0000

The Winter Gull Survey is a long-running monitoring programme which has taken place approximately every ten years since 1953. The project’s overarching aim is to provide robust information on the numbers and distributions of wintering gulls, many of which are Amber- or Red-listed, and to inform their conservation.

common_gull_janis_jonans.png

History of the Winter Gull Survey

BTO carried out the first Winter Gull Survey (WinGS) in the winter of 1952/53, to collect data on wintering gull populations in the UK. Since then, the survey has been carried out around every 10 years. However, the most recent survey was from 2003/04–2005/6, and a substantial gap in our knowledge of our wintering gulls has developed.

To address this, we will be running WinGS over the winters of 2023/24 and 2024/25, to collect up-to-date information about the five most common gull species in the UK in winter. In 2024, WinGS will also collect data during the autumn. This will be the first time that data have been collected at this time of year.

Aims of the Winter Gull Survey

The project’s overarching aim is to provide updated information on the numbers and distributions of wintering gulls in the UK, its constituent countries, the Channel Islands and the Isle of Man.

WinGS focuses on the six most numerous and widespread gull species in the UK during the winter months: Black-headed Gull, Mediterranean Gull, Common Gull, Herring Gull, Lesser Black-backed Gull and Great Black-backed Gull.

Information collected in this winter’s survey will start to fill the gaps in our knowledge which have developed since the last survey 20 years ago. This is particularly important given that gulls have been impacted by the ongoing outbreak of highly pathogenic avian influenza (HPAI), and we are still seeking to understand the full implications of this.

The updated information will help our scientists to:

Understand how wintering populations of gulls have changed over the last 20 years
Identify key autumn and wintering sites for these species, and inform their conservation
Determine how gulls have been impacted by HPAI.

Core data collected by Winter Gull Survey counts

The 2023–2025 WinGS will involve one core count in January 2024 or 2025, at known major – ‘key’ – roost sites, most of which will have been covered by previous surveys. Key roost sites will include large estuaries, lakes and reservoirs.

Gulls will be counted as they arrive to roost at dusk, and volunteers (often working as part of a team) will record the five commonest gull species in the UK (Black-headed Gull, Common Gull, Lesser Black-backed Gull, Herring Gull and Great Black-backed Gull) as well as less numerous gull species.

In order to generate complete population estimates, additional visits to sample stretches of coastline and sample inland squares will also be carried out to understand numbers and distributions outwith key sites.

Funding organisations

The Winter Gull Survey is supported by Defra, Country Nature Conservation Agencies and BTO.

Get in touch

Email us

Would you like to find out more about WinGS?

Drop us a line: wings [at] bto.org

Find us on Twitter

Subscribe to WinGS updates

Sign up for the WinGS Newsletter to hear the latest information about survey news, monitoring sites and scheme methodology.

Taking part

WEBSITEEDITOR — Tue, 01 Aug 2023 14:41:12 +0000

Find out how you can get involved in fieldwork for the Winter Gull Survey.

What skills do I need to take part?

WinGS is made up of two main counts: those at key gull roost sites, and those at ‘sample squares’ outwith the key sites.

winter_gull_survey_volunteers_mike_lane.png

Taking part in key roost site counts

Volunteers need to be confident that they can:

Count large numbers of birds accurately – roosts often number in the thousands.
Identify all gull species in flight as birds come in to roost, potentially in low light conditions.

In particular, volunteers need to be confident in identifying the six most abundant UK gull species: Black-headed Gull, Common Gull, Mediterranean Gull, Lesser Black-backed Gull, Herring Gull and Great Black-backed Gull.

Counting gulls at ‘sample squares’

If your gull ID skills are less comprehensive, you may be able to take part by counting gulls at ‘sample squares’ – additional stretches of coastline and inland areas outwith key sites. These squares are suitable for volunteers with less experience, although you will still need to be able to identify the five commonest gull species.

Improving your skills

If you want to improve your identification skills, or boost your confidence, we have resources to help you. We often run training events covering gull ID, and these are advertised on the BTO events pages.

You can also browse our gull ID videos, which are full of helpful advice for identifying both common and more unusual gull species.

How much time does it take?

The amount of time you spent volunteering for WinGS depends on the count(s) you take part in.

A single visit to a key site around dusk to count roosting gulls, in January 2024 or 2025.
Counting a ‘sample square’ on a single visit in January 2024 or 2025.
A single visit to a key site around dusk to count roosting gulls, in autumn 2024.

You will also need to spend time submitting your data to BTO.

How do I get involved?

Find a site to monitor

Key sites for WinGS counts cover the UK, Isle of Man and the Channel Islands. Search the Vacant Site Map for available WinGS sites in your area.

Sign-up and survey dates

Sign-up is now open. You now can browse and sign up for WinGS survey sites (both at key roost sites and sample squares). Please bookmark this page and check frequently for the latest updates on taking part.

Oct 2023: Sign-ups for the 2023/24 winter counts begin.
Jan 2024: Survey visit(s) for the 2023/24 winter counts. Key Date: January 21st
Apr 2024: Sign-ups for the 2024 autumn counts begin (dates TBC).
Sept 2024: sign-ups for the 2024/25 winter counts.
Jan 2025: Survey visit(s) for the 2024/25 winter counts. Key Date: January 19th

To request sites, you will need to log in to the WinGS portal.

You will need a MyBTO account to log in to the WinGS portal. If you don’t already have one, you can create a MyBTO account now.

The BTO Regional Network and the National Survey Organiser will coordinate survey allocation to ensure that the required survey coverage is achieved.

Some sites will need to be covered by a team of volunteers carrying out a coordinated count on the same evening. These are the largest roost sites, where a high skill level and/or teams of volunteers will be essential for collecting robust data. If you sign up for a ‘team site’, you will need to liaise with the local organiser or team leader prior to carrying out the counts (their details will be provided for you).

You may also be able to contact your local bird club to find out more; some (though not all) clubs may be organising groups to survey larger sites.

There is a gull roost near me that’s not part of WinGS. What shall I do?

The survey does not attempt cover all small roost sites and the sample sites will be used to estimate the total number of gulls using smaller sites. Records of gulls at smaller roosts (less than a thousand birds in total) can be entered into BirdTrack (www.birdtrack.net). However, if the roost is being used by more than a thousand birds, please contact us to let us know about it at wings [at] bto.org).

Collecting data from your site

Key roost sites

If you have signed up to visit a key roost site, you will count gulls from a fixed point as the birds arrive to roost at dusk. You may do this alone or with a team of other volunteers, especially on larger sites. If your site is part of a larger team site it is important that you liaise with the team leader and cary out the count on the agreed date.

Roost counts at key sites will involve recording a large number of birds, some of which will continue to arrive during and after dusk. We do not expect observers to be able to identify all birds to species, and you will be able to record some gulls as ‘large gull species’ or ‘small gull species’ or even just as ‘gull species’. However, it is important that as many gulls as possible are identified to the species level.

Sample squares

If you are visiting a sample square, either at the coast or inland, you will need to follow the same guidance, although sample sites are standalone sites and will not normally involve working with a team.

We will publish full instructions for data collection closer to the time of the surveys. In the meantime, you can contact wings [at] bto.org with any questions or queries.

Submitting your data

Volunteers will be able to submit their counts via an online data entry system, in the WinGS portal.

However, in the case of some ‘team sites’, counters will submit their data to the team leader for the site who will submit a total count for the site. If you are covering part of a team site, please liaise with the team leader to check how you should submit your data.

Do gull counts I’ve submitted to BirdTrack, or sent to a County Bird Recorder, feed into WinGS?

Like most structured surveys, WinGS has bespoke data needs and therefore, transferring data from one place to another often does not cover all the survey-specific details needed.

The only way to send data to WinGS is through the WinGS Online system, completing all the sections required in the WinGS form.

You can continue to add roost counts to BirdTrack and/or send them directly to your County Bird Recorder if you wish. These data can then be used in a variety of ways from each database.

Resources

Recording forms for data collection

When collecting data, you should use a WinGS-specific recording form. These will be made available on this page prior to the survey counts starting. You can download and print these forms yourself, or request paper copies from wings [at] bto.org.

WinGS Organiser Handbook

Use these links to view or download the WinGS Organiser Handbook. This outlines the responsibilities of WinGS Organisers (WOs), and is a comprehensive guide to using the WinGS Organiser options within WinGS Online.

WinGS Introduction and Overview for WOs

WinGS Introduction and Overview for WOs (PDF, 143.01 KB)
Organising WinGS Counts and Counters

Organising WinGS Counts and Counters (PDF, 103.57 KB)
Using WinGS Online for WOs

Using WinGS Online for WOs (PDF, 757.07 KB)
WinGS Methodology for WOs

WinGS Methodology for WOs (PDF, 268.67 KB)

WinGS Counter Resources

Use these links to view or download the WinGS Counters Resources. These documents outline the aims and methods of WinGS for Counters.

WinGS Introduction and Overview for Counters (PDF, 506.00 KB)
WinGS Methodology and Counting Techniques (PDF, 448.00 KB)
WinGS Online for Counters (PDF, 787.07 KB)

WinGS Recording Forms

Inland Key Recording Form (PDF, 151.79 KB)
Inland Sample Recording Form (PDF, 151.87 KB)
Coastal Key Recording Form (PDF, 150.79 KB)
Coastal Sample Recording Form (PDF, 152.49 KB)

Health and Safety information for volunteers

WinGS involves evening-time observations of inland and coastal water bodies in mid January and in autumn.

Before you take part in this survey, please assess any site-specific risks you may encounter. Risks are likely to relate to cold weather and conditions of low light. If weather conditions are adverse or access to your site becomes dangerous in snowy or icy conditions please postpone any survey efforts.

We recommend you read BTO’s guidance for volunteer fieldworkers before starting your surveys.

Get in touch

Email us

Would you like to find out more about WinGS?

Drop us a line: wings [at] bto.org

Find us on Twitter

Subscribe to WinGS updates

Sign up for the WinGS Newsletter to hear the latest information about survey news, monitoring sites and scheme methodology.

Terms and Conditions of taking part

Standard Terms and Conditions

In participating in this British Trust for Ornithology (“BTO”, “Us”, “We”) activity, scheme or survey (“Project”) you are agreeing to the following terms and conditions:

Personal data and maintaining contact

If you are providing your name, address and other personal details, BTO will store and use your personal details in line with our published Privacy Policy (www.bto.org/about/privacy-statement or you can request a copy direct). You can specify your preferences surrounding the way we contact you at any time (email info [at] bto.org, or phone 01842 750050).

More specifically with regard to this project, in order to administer your participation and to verify the data you submit, we may need to be able to contact you (usually by email, overriding any other contact preference regarding receiving email). We may need to provide your name and email address to third parties, in case they need to contact you to verify the biological data you submit.

Biological data that you submit to us

A key charitable objective of BTO is to pursue scientific knowledge and conservation outcomes, in the public interest. By submitting contributions of biological and observational data to BTO you grant us perpetual, royalty-free, non-exclusive, sub-licensable permission to use, modify and redistribute the data as we see fit, to further this objective. This may include providing data you submit to third parties for the purposes of verification, processing and further analysis and use.

You give us this permission non-exclusively, meaning that you yourself still own your contribution. You may use, distribute or modify your individual contribution in any way you like. However, you do not possess ownership of any BTO dataset itself.

Some BTO projects allow participants to flag certain records as 'sensitive', enabling us to manage the way in which information may be displayed. Subject to project-specific terms and conditions, such 'sensitive' records may be made available to appropriate third parties, according to partnership agreements or at the discretion of BTO.

You may not contribute data to BTO that you neither own, nor have express permission to contribute on behalf of another individual or organisation.

Specific Terms and Conditions applying to those who register for the WinGS Online Surveys

In addition to the standard terms and conditions, you also agree to the following:

As stated in the ‘Personal data and maintaining contact’ section of the standard terms and conditions, we may need to provide your name and email address to third parties, in case they need to contact you to verify the biological data you submit.

For WinGS, we may also need to provide your name and email address to third parties so that they can contact you to co-ordinate the surveying of a site that requires a team of volunteers to cover. Such third parties for WinGS may include WinGS Local Organisers and/or WinGS Team Leaders).

You agree that any information you supply through WinGS Online (with the exception of personal data, see Privacy Policy www.bto.org/about/privacy-statement) may be disseminated at the discretion of the WinGS partners, including under the Open Government Licence (http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/).

You confirm that if you are submitting information on behalf of anyone else then they have also agreed that their information may be disseminated in the same manner.

You agree that any information you obtain from within the WinGS Online application (other than counts submitted by you) will not be used in any presentation, publication, report, etc. or be passed on to a third party without prior written permission from the BTO. However, a distinction is made with the WeBS Report Online (www.bto.org/webs-reporting), to which information from WinGS may be published as supplementary data.

Information from WinGS may be used under the Open Government Licence with appropriate attribution, if published in the WeBS Report Online or any other such facility that states permission is given for data re-use under licence.

You accept that whilst every effort is made to ensure data held by the WinGS partners are correct, the WinGS partners cannot accept responsibility for any errors in data provided. You accept that the WinGS partners cannot be held responsible for any misuse or misinterpretation of WinGS data.

Winter Gull Survey

WEBSITEEDITOR — Tue, 01 Aug 2023 13:56:17 +0000

The Winter Gull Survey collects information about our wintering gull populations, through the coordinated effort of volunteer surveyors across the UK. It will run over the winters of 2023/24 and 2024/25. Bird IdentificationBird Survey Techniques Friday, September 1, 2023 - 00:00 to Saturday, March 1, 2025 - 00:00

The Winter Gull Survey collects information about our wintering gull populations, through the coordinated effort of volunteer surveyors across the UK.

Visit the WinGS Vacant Site Map to view and request sites in your area.
The Key Date for 2024 surveys is January 21st.
Counts can be conducted a week before and after, as close to this key date as possible.

In winter, gulls flock together to roost communally on lakes, reservoirs and estuaries, in groups that can reach the thousands.

The Winter Gull Survey (WinGS) will run over the winters of 2023/24 and 2024/25 to collect updated information on the numbers and distributions of these wintering gulls in the UK, the Channel Islands and the Isle of Man.

WinGS volunteers visit gull roost sites, counting six key species: Black-headed Gull, Common Gull, Mediterranean Gull, Lesser Black-backed Gull, Herring Gull and Great Black-backed Gull. These gulls are all of conservation concern, and their breeding populations are either Amber- or Red-listed in the UK.

Gathering more detailed information about wintering populations, and which roost sites they rely on, will help us protect them and develop more effective conservation strategies.

Find out how to volunteer for WinGS on the Taking part page.

Funding organisations

The Winter Gull Survey is supported by Defra, Country Nature Conservation Agencies and BTO.

Help monitor the UK’s threatened gull species by taking part in the Winter Gull Survey.

Emma Caulfield

Ian Woodward

Oct 2023: Volunteer sign-up for winter counts (2023/24)
Jan 2024: Survey visit(s) for winter counts
Mar 2024: Data submission
Apr 2024: Volunteer sign-up for autumn counts (2024)
Autumn 2024: Survey visit(s) for autumn counts
Sept 2024: Sign-ups for winter counts (2024/25)
Jan 2025: Survey visit(s) for winter counts
Mar 2025: Data submission
2026: Report and papers published

Subscribe to the WinGS Newsletter At least one evening visit to a gull roost or potential roosting site in January, with the option to conduct an autumn count and additional visits to sample squares. You must be able to identify gull species as they come to roost, potentially in low light levels. N/A SeabirdsUrban birdsWetland birds volunteers Yes wings@bto.org

Eco-evolutionary drivers of avian migratory connectivity

VIOLA.ROSS-SMITH — Wed, 21 Jun 2023 08:33:48 +0000

The Cuckoo cohort of 2024 takes flight!

More Details

Fattorini, N., Costanzo, A., Romano, A., Rubolini, D., Baillie, S., Bairlein, F., Spina, F., & Ambrosini, R. Ecology Letters 10.1111/ele.14223 Migratory connectivity, reflecting the extent by which migrants tend to maintain their reciprocal positions in seasonal ranges, can assist in the conservation and management of mobile species, yet relevant drivers remain unclear. Taking advantage of an exceptionally large (~150,000 individuals, 83 species) and more-than-a-century-long dataset of bird ringing encounters, we investigated eco-evolutionary drivers of migratory connectivity in both short- and long-distance Afro-Palearctic migratory birds. Connectivity was strongly associated with geographical proxies of migration costs and was weakly influenced by biological traits and phylogeny, suggesting the evolutionary lability of migratory behaviour. The large intraspecific variability in avian migration strategies, through which most species geographically split into distinct migratory populations, explained why most of them were significantly connected. By unravelling key determinants of migratory connectivity, our study improves knowledge about the resilience of avian migrants to ecological perturbations, providing a critical tool to inform transboundary conservation and management strategies at the population level.

The authors thank A. Alessi for assistance with the INDACO platform, the big data computing facility at the University of Milano. Thanks to BirdLife International for providing us with bird distribution maps. PhyloPic credits are reported at the permalink https://www.phylopic.org/permalinks/e8be1de78ea81b97484488e54bab5f61519b26a937ea4cd435b8e45c3927acdb. Special thanks go to all members of the Eurasian African Bird Migration Atlas project team and the European Union for Bird Ringing (EURING), for backing and supporting this research. Funding was provided by the Italian Government (Ministry of the Environment and Energy Safety, formerly Ministry of the Environment, Land and Sea) through a grant to the Convention on Migratory Species (CMS).

Wave of avian influenza hitting Black-headed Gulls

MIKETOMS — Mon, 15 May 2023 08:29:48 +0000

16 May 2023

Avian Influenza is killing large numbers of Black-headed Gulls at inland and coastal breeding colonies across central and northern England, prompting fears among scientists that a new wave of the disease could be building.

As many as a thousand Black-headed Gulls are thought to have been killed by Avian Influenza at Marsh Lane Nature Reserve near Coventry, while around 800 are feared to have died at RSPB St Aidans, near Leeds, and around 250 at Rutland Water. The majority of sick or dying Black-headed Gulls confirmed to have Avian Influenza have been reported from sites between Buckinghamshire and Yorkshire, with cases also reported in Surrey and Montgomeryshire.

Although only a relatively small number of dead birds are tested for Avian Influenza, current sampling suggests very large numbers of Black-headed Gulls are likely to be affected. All dead birds of any species should be reported to BirdTrack, which allows researchers to follow the disease’s geographical spread, and to Defra, which will decide if a particular case reaches the threshold for testing. These sources indicate that more than 4,000 Black-headed Gulls have died in just the past few weeks, and that the mortality rate is increasing.

This figure already represents 1% of the 140,000 pairs of Black-headed Gull thought to breed in the UK each year. Worryingly, the breeding population has already been in decline for a number of years, and the species was placed on the Amber List of Birds of Conservation Concern in 2021. The impact Avian Influenza will have on this already struggling species remains unclear, but if the current rate of mortality continues it has the potential to have a large impact on this familiar and charismatic species. Black-headed Gulls nest alongside other species, such as Common Tern, Sandwich Tern and Avocet: there are concerns that these too might be affected.

Similar mortalities among Black-headed Gulls were reported in France earlier this year, followed by birds in the Low Countries, Italy and Germany. Data from bird ringing show that Black-headed Gulls that breed in the UK often spend the winter in western continental Europe before migrating north, indicating a possible route of transmission. If the loss of breeding Black-headed Gulls is replicated across Europe, which seems likely, this could be the next chapter in the impact that this already catastrophic disease has had on European breeding seabirds, and would be likely to significantly reduce the number of wintering birds that return to the UK next autumn and winter.

Members of the public are reminded not to pick up dead birds and to keep dogs on leads to prevent them from scavenging on carcasses.

View more recent avian influenza news or learn more about the disease.

Conservation

Population dynamics

Phil Atkinson

A niche-based approach for evaluating the mechanisms of community stability in butterfly communities across three countries

MIKETOMS — Wed, 22 Mar 2023 09:34:18 +0000

The Cuckoo cohort of 2024 takes flight!

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Evans, L.C., Melero, Y., Schmucki, S., Boersch-Supan, P.H., Brotons, L., Fontaine, C., Jiguet, F., Kuussaari, M., Massimino, D., Robinson, R.A., Roy, D.B., Schweiger, O., Settele, J., Stefanescu, C., van Turnhout, C.A.M. & Oliver, T.H. Global Change Biology 10.1111/gcb.16684 At large scales, the mechanisms underpinning community stability in natural populations may vary in importance due to changes in species composition, mean abundance, and species richness. Here we link species characteristics (niche positions) and community characteristics (richness and abundance) to evaluate the importance of stability mechanisms in 140 butterfly communities across three European countries and spanning five bioclimatic regions. We construct niche-based hierarchical structural Bayesian models to explain first differences in abundance, population stability, and species richness between the countries, and then explore how these factors directly and indirectly (via synchrony and population stability) impact community stability. Species richness was partially explained by the position of a site relative to the niches of the species pool, and species near the centre of their niche had higher average population stability. The differences in mean abundance, population stability, and species richness then influenced how much variation in community stability they explained across the countries. We found, using variance partitioning, that community stability in Finnish communities was most influenced by community abundance, whereas this was unimportant in Spain with species synchrony explaining most variation; the UK was somewhat intermediate with both factors explaining variation. Across all countries, the diversity-stability relationship was indirect with species richness decreasing synchrony which increased community stability, with no direct effects of species richness. Our results suggest that in natural communities, biogeographic variation in key drivers of stability, such as population abundance and species richness, lead to community stability being limited by different factors and that this can partially be explained due to the niche characteristics of the European butterfly assemblage. We thank the volunteers collecting butterfly data and the funders of the schemes for the obtaining the data required for this study. The UK Butterfly Monitoring Scheme is organized and funded by Butterfly Conservation, the Centre for Ecology and Hydrology, British Trust for Ornithology, and the Joint Nature Conservation Committee. The Catalan BMS is funded by the Catalan Government, the Barcelona Provincial Council and other local partners. The Catalan BMS also incorporates the Andorra BMS that is run by CENMA and funded by Govern d'Andorra. The Finnish BMS is organized and funded by the Finnish Environment Institute (SYKE) and the Finnish Ministry of Environment.

BirdTrends 2022: Trends in numbers, breeding success and survival for UK breeding birds

WILLIAMSKELLORN — Wed, 15 Feb 2023 11:45:03 +0000

The Cuckoo cohort of 2024 takes flight!

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Massimino, D., Woodward, I.D., Barber, L., Barimore, C., Harris, S.J., Leech, D.I., Noble, D.G., Walker, R.H., Baillie, S.R. & Robinson, R.A.