The annual update of the UK’s Biodiversity Indicators was published today by Defra.  These are important metrics, reporting on the state of the UK’s biodiversity, the pressures it faces and the conservation action that is being undertaken in response. Today’s blog by Fiona Burns, Senior Conservation Scientist explains.

Our inter-related responses to the state of biodiversity and the pressure of climate change are very much in our minds at present, with the UN Climate convention, COP26, starting in Glasgow next week and discussions underway to develop a new international plan to recover nature (the post-2020 Global Framework), which will be finalised at the UN Biodiversity conference, COP 15, in spring 2022.  Going forward, the set of Biodiversity Indicators published today will help us track the UK’s progress towards the new global targets to recover nature. 

Alongside these international agreements, there is increasing interest around the world for governments to legislate for legally binding targets for the recovery of nature and therefore having in place robust measures, such as Biodiversity Indicators, to allow us to measure progress to these targets is critical.  For example, the Westminster Environment Bill is in its final stages of progress through Parliament and the current wording requires the government to set a ‘species abundance target’ [for England] that ‘…would halt a decline in the abundance of species…’. 

The importance of volunteers

Before we get into the specifics of what the Indicators are telling us, is it worth pausing to reflect that a substantial proportion of these measures rely on the dedication and expertise of thousands of volunteers, whether that is searching for butterflies is a warm meadow, detecting bats along tree lines at dusk or submitting records of a myriad of groups from lichens to hoverflies.

We could not report on the state of our biodiversity or assess its response to pressures or conservation without this critical contribution.

Species trends

The most well-known of the species indicators are those for wild birds (C5, page 36), which the RSPB produces in collaboration with the BTO – those in today’s report are actually the same ones as published previously, in November 2020

They show the by now familiar pattern of dramatic loss in farmland birds, with populations having declined by 55% on average since 1970; it is important to note that although the greatest losses occurred in the period of rapid change in farmland management methods in the 1970s and 80s, in recent years the trend has continued to decline steadily, with a fall of 5% in the last five years.  Similarly, the woodland bird indicator, down by 25% since 1970, has fallen by 7% in the last five years. 

Breeding farmland birds in the UK, 1970 to 2019 (c) UK Biodiversity Indicators 2021

Biodiversity loss in the UK is sometimes portrayed as something which happened in the past, but which has now been stabilised: as these measures show, this is simply not the case. We should, however, celebrate the increase in the ‘mammals of the wider countryside (bats)’ indicator (C8, page 44) which has risen by 47% since 1999: the increases shown by a range of bat species are believed to be a recovery from major population declines in the 20th century.

Lesser horseshoe bats are one of the three species of bat which have seen large statistically significant increases in populations (c) Ján Svetlík (Flickr-CC BY-NC-ND 2.0)

Measures for other taxa also show loss; in the case of butterflies (‘Insects of the wider countryside’, C6) habitat specialists have fallen by an average of 61% since 1976, and species of the wider countryside by 22%. Finally, the indicators on the status of priority species (C4), which RSPB scientists have been heavily involved in developing alongside our partners at the UK Centre for Ecology and Hydrology, show that even the species identified by the UK’s governments as the highest priorities for conservation efforts have continued to decline.  On average, priority species for which we have measures of abundance have declined by 61% since 1970 (and increased by 1% in just the last five years), and those for which we have measures of distribution have declined by 4%.  

Protected Areas

The Indicator set also includes a measure charting the extent of Protected Areas in the UK on land and at sea (C1).  This Indicator shows a rapid increase in recent years, driven primarily by an expansion in coverage of Marine Protected Areas, with current estimates of the proportion of land and sea in Protected Areas at around 30%.

This is clearly very positive news, however, a recent paper estimated that as little as 5% of UK land may be effectively protected for nature given that some types of Protected Area included in the official Indicator are not primarily designated for nature conservation, for instance Areas of Outstanding Natural Beauty, and that many sites are not in ‘favourable’ condition.

Coquet island is one of the islands strictly protected for nature under the IUCN categories (c) David Wootton (

English Biodiversity Indicators

The English Biodiversity Indicators are also out today. These cover much of the same ground as the UK Indicators.  The main development this year is that a new Priority species Indicator (4) has been published for England, charting the average change in abundance and distribution of species on the S41 list.  On average, species on the S41 list have declined in abundance by 82% since 1970 and declined in occupancy by 16%.

Many of the priority species are listed due to conservation concern, so it is not unexpected that the Indicator declines initially, but what is concerning is that we have failed to halt the loss of these species, many of which were identified as conservation targets more than twenty years ago.

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