The latest BTO/RSPB/JNCC Breeding Bird Survey (BBS) report shows the very different fortunes in England for two almost identical warblers, the Willow Warbler and the Chiffchaff.
Due to the varying COVID-19 restrictions across the UK the 2020 BBS report can only publish the latest trends for a reduced set of species in England but it still makes for very interesting reading. Both the Willow Warbler and the Chiffchaff breed throughout England and both are found in woodland, woodland edge and scrub habitats but their fortunes here are very different. During the last 24 years the Willow Warbler has seen its breeding population decline by 45%, whilst that of the Chiffchaff has increased by 114% over the same period.
Willow Warbler and Chiffchaffs look very similar and inhabit very similar habitat during the breeding season, yet they have a very different migration and overwintering strategy. The Willow Warbler is a long-distance migrant that spends the winter months in sub-Saharan Africa, whilst the 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 overwinter period that are contributing to their very different long-term trend.
Two other woodland birds, the Nuthatch and the Great Spotted Woodpecker, have seen their populations more than double during the last 24 years, up by 105% and 117% respectively but the same can’t be said of another familiar hole-nesting bird; the Starling has seen its breeding population fall by 60% over the same time 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 report shows that over the last 24 years, the Red Kite has increased by a staggering 18,695%. The reintroduction of this bird to our skies now means that many of us can see them from our own backyards and it is incredible to think that as recently as the early 80s, this amazing bird was heading towards extinction in the UK.
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, said, “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 the 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 BTO/JNCC/RSPB 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
Header image: Allan Drewitt.