The 2021 report of the Rare Breeding Birds Panel was published in British Birds in November 2023 (Eaton et al. 2023) and can be obtained by subscription at www.britishbirds.co.uk; a pdf of the report will be available on this website in due course.
The report documents the status of the 111 species and subspecies of rare and scarce native birds that were recorded breeding, or showing signs of breeding, in the UK in 2021; this is by far the highest number of taxa reported on in a single year by the Rare Breeding Birds Panel. Population totals are given for each species in the report, alongside a breakdown in records by country and recording area, and where possible updated trends are given. A table summarising species’ totals and trends can be found here. In addition, records were compiled for 12 rare non-native breeding species.
The RBBP report for 2020 was heavily compromised by the impacts of Covid-19 lockdowns on fieldwork in the spring of that year and the resulting effect on data availability. As a consequence, the recording and reporting of most rare breeding birds was adversely affected, and we did not publish updated population estimates and trends for these species in our 2020 report. In the 2021 report we return to publishing updated statistics for all the species for which we believe our normal data flows are sufficiently complete, with 2020 data omitted from the calculations of 5-year means and trends. However, we do acknowledge that continued lockdown restrictions in the spring of 2021 may have again reduced field activity, albeit not to the same extent as in 2020. All four UK countries entered new lockdown periods in late December 2020 or early January 2021, with restrictions being eased incrementally from March onwards. As in 2020, impacts may have been greatest in Wales, and most significant for the recording of species for which early season fieldwork is important, such as Lesser Spotted Woodpecker, but there is no evidence to suggest a significant impact on UK-level reporting for any species.
Ospreys; Ewan Weston
The 2021 report was enabled by the collation of just over 10,000 individual records, which, once duplicate records were identified, provided 7,300 unique records. The most important sources of data are the detailed submissions compiled by the UK’s county and regional bird recorders. These recorders, all of whom are volunteers, are uniquely placed to understand the relevance and context of the records they receive from birders. Of course, county recorders, and in turn RBBP, are highly dependent on observers submitting records in the first place. It is vital that birders across the UK continue to make their sightings available, not least for the value these records have for conservation, as outlined in this report. Other than data submitted by county bird recorders, our important data sources include returns from Schedule 1 licence holders, the BTO/JNCC Nest Record Scheme, raptor study groups, annual species’ monitoring, periodic national surveys, and counts from RSPB reserves.
The new record total of 111 rare species or races reported on for 2021 is in some part due to a considerable number of records of vagrant individuals demonstrating breeding behaviour, including the first RBBP records of Marsh Sandpiper, Elegant Tern and Dusky Warbler, and the second records of Buff-breasted Sandpiper, American Black Tern and Yellow-browed Warbler. In addition to these examples, there are records for another ten species for which we have never reported confirmed breeding in the UK, plus long-staying individuals of Pied-billed Grebe and Ring-billed Gull.
We also report on various species of herons and allies that may be on the verge of colonisation from continental Europe – Glossy Ibis, Night Heron, Little Bittern and Purple Heron – although none were proven breeding in 2021. Perhaps more significantly, all of the more established long-legged colonisers – Common Crane, Eurasian Spoonbill, Cattle Egret, Great White Egret and Little Egret – reached record totals in 2021, as did Eurasian Bittern. Also pleasing is that four raptor species – Osprey, Marsh Harrier, White-tailed Eagle and Northern Goshawk – reached new record totals in 2021, with the number of reported pairs of the latter exceeding 1,000 for the first time.
Red-necked Phalarope; Mark Eaton
One particularly surprising event was the return of Temminck’s Stint, with a pair almost certainly laying eggs in Highland before the nest site was flooded; the last confirmed breeding record in the UK was in 1997. Other northern breeding waders are flourishing; the Red-necked Phalarope population in the UK reached a new high of 146 pairs, while both Green and Wood Sandpipers also reached new record totals. Not all northern breeders are faring well, however. Most notably, the maximum total of 20 pairs of Slavonian Grebes is the lowest since RBBP reporting began in 1973, and only three female Ruffs were reported attending leks. Numbers of another lekking species, the Capercaillie, were the lowest since lek-monitoring was established in 2003. Further south, both Montagu’s Harrier and Yellow-legged Gull failed to breed for the second year in succession.
As 2023 marks the 50th anniversary of the establishment of the Rare Breeding Birds Panel as an independent organisation, we have used the occasion to look back to our first report, for 1973, to see how our rare breeding bird populations have changed since then. Three of the species featured in the very first report (Red Kite, Cetti’s Warbler and Firecrest) are now too abundant to be covered by the RBBP, and there are another 14 that have clearly increased in numbers since 1973 – for example, Avocet, Mediterranean Gull and Common Goldeneye. Twelve species, including Black-tailed Godwit, Black Redstart and Savi’s Warbler, have shown relatively little change in status since 1973, although, in some cases, there have been considerable fluctuations over the intervening decades. Finally, there are 11 species for which numbers are now clearly lower than 48 years ago, including Red-backed Shrike, Common Scoter and Marsh Warbler.
As always, we wish to thanks all those who support the work of the RBBP, particularly those who collate and submit data to us, and the observers who make the thousands of records of rare breeding birds that contribute to our reports.
Dr Mark Eaton
Secretary, Rare Breeding Birds Panel, 1st November 2023.