Think tank disputes government data on farmland bird decline

A major government report suggesting UK farmland bird populations are in serious decline has been strongly challenged by the Science for Sustainable Agriculture (SSA) think tank, which says the data is outmoded.

The Defra report, Wild bird populations in the UK and England, 1970 to 2024, is based on a set of 19 species.

It suggests farmland bird numbers have dropped by 62% since 1970, highlighting steep long-term declines in farmland specialists such as the turtle dove and tree sparrow.

“The most severe population declines occurred between the late 1970s and early 1980s, largely due to the negative impact of rapid changes in farmland management during this period,” it says.

“Although it has slowed since this period, populations have continued to decline at a fast rate, by 11% in the five years since 2019,” it adds.

However, SSA claims the government’s indicator list is “limited and highly selective” and does not reflect the full picture of British farmland bird life.

See also: Farmland bird count shows success of farmer-led conservation

“SSA is urging Defra to review the quality of its evidence base… and seriously to question whether the indicator list used… is still relevant and fit for purpose,” said SSA co-ordinator Daniel Pearsall.

SSA’s analysis, using its own list of 64 farmland-associated species, including carrion crows, red kites, and chaffinches, suggests UK songbird numbers have remained stable.

According to SSA, the UK songbird population rose slightly from 70.3m in 1997 to 71.3m in 2024.

“The discrepancies between our findings and the Defra report raise serious questions about the evidence base ministers are relying on,” added Mr Pearsall.

Many factors

The SSA states that “biodiversity is not static” and that species fluctuate in abundance due to a combination of factors such as predation, disease, climate change, and competition.

Mr Pearsall also raised concern about “the government’s reliance on data and analysis from environmental NGOs… whose existence thrives on negative assessments”.

But a spokesman from the Royal Society for the Protection of Birds insisted that the new data “shows once again concerning declines in farmland birds”.

“What we’ve seen for the past 50 years is that yellowhammers, turtle doves, lapwing, and other farmland birds are in a dramatic freefall.

“Yet, we also know that farmers working with nature can reverse these declines while also improving long-term food production.

“We need the UK government to roll out a set of effective and well-funded nature-friendly schemes at scale, enabling farmers to manage 10% for nature, providing the year-round resources for farmland birds to rebound.

“This includes ensuring farmers already in schemes can continue to access funding.”

Scottish scene

SSA also cited data from NatureScot, showing a 7% rise in Scotland’s farmland bird numbers since 1994, and a 10% increase in its overall wild bird index.

“There is no perfect blueprint for biodiversity,” said Mr Pearsall.

“But… there is good evidence to indicate that individual bird numbers and the physical ‘biomass’ of bird life in the farmed countryside have remained broadly stable for the past three decades.”