Status of UK priority species indicator (Relative abundance)
C4a. Relative abundance
Type: State Indicator
This indicator shows changes in the relative abundance of priority species in the UK for which data are available. The relative abundance of each priority species in this indicator is the estimated population (abundance) of that species in the latest year of the time series taken as a percentage of its estimated population in the earliest year of the time series (i.e. the base year). The indicator will increase when the population of priority species grows on average and decrease when the population declines. This indicator should be read in conjunction with C4b which provides data on those UK priority species for which distribution information is available.
No new data since the previous publication, however a combined evaluation of the long-term change in the relative abundance anddistribution of priority species (C4a and C4b) has been added to the background section of this update.
Official lists of priority species have been published for each UK country. There are 2890 species on the combined list; actions to conserve them are included within the respective countries’ biodiversity or environment strategies.
By 2015, the index of relative abundance of priority species in the UK had declined to 32% of its value in 1970, a statistically significant decrease. Over this long-term period, 27% of species showed an increase and 73% showed a decline.
Between 2010 and 2015, the index declined by 18% relative to its value in 2010, again showing a statistically significant decrease. Over this short-term period, 42% of species showed an increase and 58% showed a decline.
Change in the relative abundance of priority species
C4ai. Change in the relative abundance of priority species in the UK, 1970 to 2015.
- Based on 215 species. The line graph shows the unsmoothed trend (dotted line) with its 95% confidence interval (shaded).
- The bar chart shows the percentage of species increasing or declining over the long term (1970 to 2015) and the short term (2010 to 2015).
- All species in the indicator are present on one or more of the country priority species lists (Natural Environmental and Rural Communities Act 2006 – Section 41 (England), Environment (Wales) Act 2016 section 7, Northern Ireland Priority Species List, Scottish Biodiversity List).
Source: Bat Conservation Trust, British Trust for Ornithology, Butterfly Conservation, Centre for Ecology & Hydrology, Defra, Joint Nature Conservation Committee, People’s Trust for Endangered Species, Rothamsted Research, Royal Society for the Protection of Birds.
Assessment of change in the relative abundance of priority species in the UK
|Long term||Short term||Latest year|
|Priority species - Relative abundance||
|No change (2015)|
Download Technical background document
Download Evidence statement
Last updated: July 2018
Latest data available: 2015