Latest BBS report shows the ups and downs of English birds

The latest BTO/RSPB/JNCC Breeding Bird Survey (BBS) report highlights the differing fortunes in England for many species – notably including two similar-looking warblers, Willow Warbler and Common Chiffchaff.

Due to varying COVID-19 restrictions across the UK in 2020, the latest BBS report can only publish updated trends for a reduced set of species in England – though it still makes for very interesting reading. Both Willow Warbler and Common Chiffchaff breed throughout England and both are found in woodland, woodland edge and scrub habitats, but their fortunes are very different. During the last 24 years Willow Warbler has seen its breeding population decline by 45%, while that of Common Chiffchaff has increased by 114% over the same period.

Willow Warbler is struggling nationally, while its close relative, Common Chiffchaff, is on the increase (Douglas Dickson).

Willow Warbler and Common Chiffchaff look very similar and inhabit similar habitat during the breeding season, yet they have a very different migration and overwintering strategy. Willow Warbler is a long-distance migrant that spends the winter months in sub-Saharan Africa, while Chiffchaff is a short-distance migrant that heads to Europe and as far south as North Africa – some of our breeding chiffchaffs may even stay here in the UK during the winter months. So, it is likely that they face very different pressures during the migration and overwintering period that are contributing to their very different long-term trends.

Two other woodland birds, Eurasian Nuthatch and Great Spotted Woodpecker, have seen their populations more than double during the last 24 years, up by 105% and 117% respectively. However, the same can't be said of another familiar cavity-nesting bird: Common Starling has seen its breeding population fall by 60% over the same period.

For one bird the change in its fortunes couldn't be more different from the handful of pairs that called a few Welsh valleys 'home' in the 1980s. The BBS report shows that over the last 24 years, Red Kite has increased by a staggering 18,695%. The reintroduction of this raptor to English skies now means that it can be seen from gardens in many areas. This represents a stark turnaround from the early 1980s, when it was plunging towards extirpation in the UK.

Red Kite has fared astonishingly well across England over the past two decades (Geoff Snowball).

Sarah Harris, BBS National Organiser at the BTO, said: "2020 was a very difficult year for many, and it looked like we might have a very poor survey season for BBS coverage and data; the first since 2001 when Foot and Mouth kept us out of the countryside. However, restrictions were lifted just in time for some of our brilliant volunteers to get out and monitor their BBS squares, and it is down to them that we have anything to report on at all! Thanks go to all the current and retired BBS volunteers that we have such a powerful long-term dataset allowing us to track the contrasting fortunes of species such as Willow Warbler and Red Kite."

Dr Mark Eaton, RSPB's principal conservation scientist, added: "Many of the UK's birds are struggling, and the losses seen in these species are not sustainable. More needs to be done to stop these declines and help populations recover. Amazing examples of conservation in action, such as for Red Kite, show what can be achieved with sufficient commitment, knowledge and resources. It's been remarkable to see a species once persecuted to near extinction in this country, brought back and welcomed by local communities, with local economies reaping the dividends of the return of this breath taking species."

Dr Paul Woodcock, Biodiversity Evidence Specialist at JNCC, said: 'It's impressive that despite the reduced data collected in 2020, reliable trends for many species could still be produced from the BBS. This again shows the value of having such a strong long-term dataset – thank you to everyone who has contributed over the years'.

The Breeding Bird Survey is a partnership jointly funded by the BTO, RSPB and JNCC, with fieldwork conducted by volunteers. The full report can be read here.