In recent years, our endemic race of willow tit (Poecile montanus kleinschmidti) have been lost from large areas of southern and eastern England and from parts of north and south Wales. Senior Conservation Scientist Simon Wotton explains why a survey was needed for this woodland birds, and what it shows us.
The willow tit is the fastest declining resident bird species in the UK, and the second-fastest declining species overall, after turtle dove. The population has declined by 86% between 1995 and 2020, although while the BTO/JNCC/RSPB UK Breeding Bird Survey is still able to produce an annual UK trend, the sample size is now very low, with just 17 occupied BBS squares in 2021.
Willow tit (c) Mark Eaton
Due to the declining numbers and range, monitoring is becoming increasingly difficult. A national survey was therefore needed if ongoing conservation work is going to be properly underpinned by robust evidence.
The first national willow tit survey was undertaken between 2019 and 2021, with county-level surveys undertaken across the known range by Willow Tit study groups, county bird clubs, other conservation organisations and other volunteers. The survey was organised by RSPB, with support from the Rare Breeding Birds Panel, Natural England (through the 'Action for Birds in England' partnership), Natural Resources Wales and the Welsh Ornithological Society.
Survey results
Although badly affected by Covid-19 restrictions in 2020 and 2021, it has been possible to produce estimates at country and county levels across the range in England, Scotland and Wales. Overall, data from over 1,900 tetrads were used for the survey analysis: c1,400 in England, c140 in Scotland and c430 in Wales.
The survey results show that the willow tit population in Great Britain is estimated at nearly 5,700 breeding pairs of which 76% were in England, 21% in Wales and 3% in Scotland. The ‘top 3’ ceremonial counties across Britain were North Yorkshire, County Durham and Derbyshire. In Wales, most of the population were in Carmarthenshire, Ceredigion, Breconshire and Montgomeryshire. Almost all the willow tits in Scotland were in Dumfries & Galloway.
Looking ahead
This is the first time that robust population estimates have been produced for willow tit, at the country and county levels. The country estimates are higher than anticipated, given the ongoing decline of the species. This is likely to be due to a combination of lower detectability during the Atlas fieldwork, particularly in tetrads with higher densities of willow tits, and the greater detectability of the bespoke playback method used for this survey.
Work is ongoing to understand the causes of willow tit population decline. The results from this survey can help target conservation action at local and regional levels. A key tool will be the newly published Willow Tit Conservation Handbook from the recent Back From the Brink project, for those who are looking to undertake practical habitat management for willow tit, which provides advice on habitat management techniques and monitoring and surveying methods with supporting information on ecology and case study examples.
Many thanks go to the study groups and county bird clubs who helped with the survey, and to all the volunteers who took part in the survey.
Collation of annual records will become increasingly important for willow tit and we encourage everyone to continue to look out for willow tits and submit sightings to Birdtrack.
This willow tit survey is part of Action for Birds in England, a conservation partnership between Natural England and the RSPB.
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