2018 Breeding Bird Survey
Britain's birds hit by weather double whammy in 2018 – 2018 Breeding Bird Survey results now published
The latest results published today in the 2018 Breeding Bird Survey (BBS) report, suggest that the Beast from the East and Saharan winds may have had a big impact on both resident and migrant birds.
The short, sharp impact of the snow and ice that came with the Beast from the East may have affected some of our smallest birds in particular. Goldcrest, the smallest UK bird, saw a population decline of 38% and Wren and Long-tailed Tit were both down by 21% and 22% respectively in comparison with 2017 figures. As a group these birds are the real lightweights of the bird world, weighing in at between 5-10g. As such they can be particularly vulnerable to cold weather, and even though the Beast delivered a brief shock, it appears this was enough to hit these birds hard.
It looks as though the very cold spell also hit one of UK’s most colourful birds, the Kingfisher. The sudden freezing of shallow water can prevent them from accessing the small fish they feed on; the 2018 breeding population was down by 38% on the previous year.
While all this was unfolding in the UK, our summer visitors were safely ensconced in sub-Saharan Africa, thousands of miles from any snow and ice. However, when the time came to head back to the UK, the Sahara desert was experiencing strong northerly winds, seemingly hampering the northward return journey and many were late back or arrived in lower numbers. This appears to have had quite an impact on the number of returning birds and House Martin was down by 17%, Sand Martin down by 42% and Swift down by 20% during the 2018 breeding season surveys. It wasn’t just the aerial feeders that were affected; two of our commonest warblers, Whitethroat and Willow Warbler were down too, by 18 and 23% respectively. Whilst some of these birds may have been affected by the weather during migration, it is unknown what effect conditions in their over-wintering grounds might have had on these year-to-year population changes.
It wasn’t all bad news and some birds apparently managed to either tough it out through the snow and ice, or find a window in the winds to cross the desert. Grey Heron is a species that is vulnerable to cold weather and over the years its breeding population has seesawed with cold and mild winters. However, the large size of the Grey Heron, standing around a metre tall, may have allowed it to weather the storm and its 2018 breeding population remained stable.
The Cuckoo was one of the long-distance migrants that managed to time its flight across the desert to coincide with better winds. Not only did they arrive back on cue, they returned to breed in good numbers; up by 22% on 2017. A welcome break for a species suffering a long-term decline of 41% (1995–2017).
Paul Woodcock, Evidence Specialist at JNCC, said, “The great work done by volunteers on the Breeding Bird Survey means that we now have information on UK breeding bird species from over 4000 sites across the UK. The annual data provided by the BBS – which goes back as far as the mid-1990s in many sites – is therefore an invaluable conservation resource for helping to understand how and why UK bird populations are changing as a result of environmental pressures and conservation activities”.
The BTO/JNCC/RSPB Breeding Bird Survey is a partnership jointly funded by the BTO, RSPB and JNCC, and the report is published by BTO annually on behalf of the partnership.
The full report can be accessed here: https://www.bto.org/our-science/projects/bbs/latest-results/population-trends
The full list of JNCC Official Statistics can be accessed here: http://jncc.defra.gov.uk/page-5779