D1. Biodiversity and ecosystem services

D1c. Status of pollinating insects

 

Type: State / Benefit indicator

 

Indicator Description

This indicator illustrates changes in pollinator distribution (bees and hoverflies) in the UK.  The indicator is based on 351 species of pollinator (137 species of bee and 214 species of hoverfly), and measures change in the number of 1km grid squares across the UK in which they were recorded in any given year – this is referred to as the ‘occupancy index’.  Many insect species are involved in pollination but bees and hoverflies are known to be important and are presented here as an indicator of overall pollinator trend. 

 

Summary

 

There was an overall decrease in the pollinators indicator from 1987 onwards.  In 2016, the indicator had declined by 22% compared to the value in 1980.  The long-term trend was assessed as a decline.

Between 2011 and 2016 the indicator showed a minor increase of 2%, however given the uncertainty, the short-term trend was assessed as stable.

Over the long term, 14% of pollinator species became more widespread (5% showed a strong increase), and 34% became less widespread (13% showed a strong decrease).  The ratio between increasing and decreasing species was more balanced over the short term, with 39% of species increasing and 38% of species decreasing.

As individual pollinator species become more or less widespread, the communities in any given area become more or less diverse, and this may have implications for pollination as more diverse communities are, in broad terms, more effective in pollinating a wider range of crops and wild flowers.  Despite the inter-annual variation, the overall trend for pollinators remains downward.

 

Figure D1ci.  Change in the distribution of UK pollinators, 1980 to 2016.

 

Figure D1ci. Change in the distribution of UK pollinators, 1980 to 2016.

 

Notes:

  1. Based on a total of 351 pollinators, comprising 137 wild bee species and 214 hoverfly species.
  2. The graph shows the unsmoothed composite indicator trend with variation around the line (shaded) within which we can be 90% confident that the true value lies (credible interval).
  3. The bar chart shows the percentage of species within the indicator that have increased, decreased or shown no change in occupancy, based on set thresholds of change.
  4. This indicator is not directly comparable with the previous publication as the Bayesian modelling methods have been improved and 38 species (10 wild bees and 28 hoverfly species) have been removed from the analysis.

Source:  Bees, Wasps & Ants Recording Society; Hoverfly Recording Scheme; Biological Records Centre (supported by Centre for Ecology & Hydrology and Joint Nature Conservation Committee).

 

Assessment of change in the distribution of pollinators in the UK

 

Long term

Short term

Latest year

Distribution of UK pollinators

indicator declining
1980–2016

2010 indicator stable2011–2016

Increased (2016)

 

 

 

Download Fiche

Download Datasheet

Download Technical background document

Download Technical background document on Bayesian Occupancy Models

Download Evidence statement

 

Last updated: July 2018

Latest data: Pollinators and wild bee species (2016), hoverfly species (2013)