BIRD POPULATIONS IN the UK are continuing to decline as the government seemingly abandons its own targets set out by the Environment Act 2021.
New data released by the UK government has revealed that 48 per-cent of bird species declined between 2015 and 2020, with iconic British breeds such as the turtle dove falling 98 percent since the 1970s. Monitoring bird populations provides a vital indicator of the broader state of wild-life in the UK, as birds occupy a vast range of ecological niches, so must respond to wide-ranging environmental pressures. Trends in bird populations also reveal the impact of environmental management practices, particularly in woodland and farmland where they have experienced long and short-term decline.
Individual species population trends were calculated as annual in-dices “relating the population in a given year to the baseline data” in the first year of study. The report revealed woodland birds to be the most impacted between 2015 and 2020, with woodland species showing a 59 percent decline. Woodland covers 13 percent of all UK land area, providing habitats for both generalist and specialist birds. In 2021 the index for woodland specialists such as the wil-low tit was 53 percent lower than in 1970.
In contrast, many woodland gen-eralists, such as the long-tailed tit, seem to have adapted to using gardens and borders of farmland with an index three percent higher than in 1970. Both native and migratory woodland species in the UK are under threat due to a lack of effective woodland management, including controlling deer browsing, which is reducing the number of available nesting and foraging habitats.
Despite the short-term decline in woodland species, it is farmland bird populations that have suffered the most, with 63 percent of species in decline. Agricultural land covers a colossal 75 percent of the UK’s land mass, thus its management is strongly interwoven with the survival of our wildlife. The government and various non-profit organisations such as the RSPB believe a significant proportion of this decline is due to historical changes in agricultural practice in the 1950s and 1960s. Profound droughts in the 1950s caused expansive food shortages throughout the country and many farms created irrigation systems to alleviate their losses. The unintended effects of agricul-tural development in the last 70 years include water shortages and habitat loss. Between 1970 and 2021, 71 percent of farmland specialists such as the skylark and grey partridge declined alongside changes in the agricultural sector. Farmland generalists including the greenfinch and kestrel are also in modest decline. The government has attributed some of these declines to trichomonosis, a disease that has se-verely impacted greenfinch and turtle dove populations in recent years.
The RSPB’s publication of results from this year’s Big Garden Birdwatch further revealed that many of our gar-den birds are also disappearing. The house sparrow remained the most common garden visitor for the twen-tieth year running, however, nearly 22 million birds are believed to have disappeared since the survey began in 1979. Many York students don’t have a garden, so the University’s campuses often take the role of our communal green spaces.
The annual report of the Wetland Bird Survey for 2021/2022 revealed many of our campus inhabitants to be in decline. Whilst resident geese such as the Canada goose, greylag goose and barnacle goose all show positive trends, the mute swan population has shown a three percent decline in the last 10 years – possibly reflecting the mortality of avian influenza.
Ducks and other waterfowl also demonstrate long-term declines with mallards (a ten-year trend of 22 per-cent), pochards (-39 percent), and coots (-27 percent) all particularly af-fected. However, it’s not all bad news for our campus residents. Mandarin duck populations are at a record high (providing hope for another Fancy Boi) whilst goosander populations (winter visitors at York) remain stable. Many bird species inhabiting standing water such as tufted ducks, are showing an increasing preference for artificial bodies of water, causing population densities to shift in location according to the greater availabil-ity of these habitats. Despite the risk of increased predation, the campus lakes at York provide a nurturing environment for many native and visiting waterfowl.
