The latest Breeding Bird Survey (BBS) report on the UK’s bird species shows that one summer visitor is enjoying what Northern Ireland has to offer. How do we know? In 2019, skilled, dedicated volunteers walked towns, cities, farmland, woodlands, mountains and everything in-between to collect invaluable data from 119 1-km survey squares.
During the surveys, information on bird numbers, habitat types and mammal data were recorded and, in turn, used to produce population trends – the news is mixed.
The blackcap, a widespread bird across the UK, has laid claim to Northern Ireland in style. Its breeding population has seen an increase of 1,540% during the last 23 years, an even greater increase than is being enjoyed by this melodic warbler across the UK. A combination of climate change, earlier laying dates than in the late 1980s and their short-distance migration are thought to have benefited the species, allowing them to expand in range and increase in abundance over time.
The greenfinch is a well-known bird in Northern Ireland, being a frequent visitor to garden feeding stations but how much longer might this be the case? The 2019 Breeding Bird Survey results show an alarming decline; during the last 23 years the greenfinch population has fallen by 82%. The cause of this decline is thought to be Trichomonosis, a disease that has been known in cage birds for some time. Now noted in wild finches it causes infected birds to be lethargic, fluffed-up and unable to feed. Transmission between birds can be via contaminated food and water, e.g. at garden feeding stations. Good feeding station hygiene, with regular cleaning and disinfecting can help to slow the spread. The Trichomonas gallinae parasite is specific to birds and does not pose a health risk to humans or their mammalian pets.
In Northern Ireland, it is possible to monitor the population changes for 34 bird species and it is all thanks to the dedication of the BBS volunteers who go out every spring to survey Northern Ireland’s birdlife.
Katherine Booth-Jones, Science Officer for BTO Northern Ireland, “There is an amazing network of BTO volunteers in Northern Ireland, who we rely on to chart the fortunes of our bird life. Results of the BBS show that the greenfinch, a beloved visitor to many people’s gardens, is declining more in Northern Ireland than in other parts of the UK. This is a worrying trend and it is thanks to the efforts of our volunteers and funding from the Northern Ireland Environment Agency that we are able to keep an eye out for all our bird species across the country.”
Mark Eaton, RSPB’s Principal Conservation Scientist, said “Greenfinches are fantastic little birds, and the flashes of green and yellow used to be a common sight at our bird feeders. The food we put out for these little seed-eaters has become increasingly important over the years, as food availability in the wider countryside has reduced. Continuing to provide food is important but you can help them, and other birds, by cleaning your feeders and water sources every couple of weeks with a mild disinfectant.”
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.
For more information on the ups and downs of birds in Northern Ireland the full report can be accessed here.
Header image: blackcap. Credit: Bethan Clyne.