OPAL data tracks spread of Tree Bumblebee

Tree bumblebee nectaring on marjoram

OPAL Species Quest survey data has provided an invaluable insight into the spread of the Tree Bumblebee (Bombus hypnorum), writes community scientist Annie Robinson.

The data has recently been utilised in a publication by OPAL scientists at the University of Aberdeen, comparing how citizen science recording schemes can map distribution of species compared to more traditional recording schemes.  

In summary, the two non-expert citizen science initiatives (BeeWatch and OPAL), revealed a remarkably similar and widespread occurrence of the Tree Bumblebee species across England, as seen in the maps below, despite having very different methods.  

Records from both non-expert ('lay') citizen science approaches were less clustered than naturalist records held by NBN. This was particularly the case in a comparison of NBN and BeeWatch data for the Common Carder Bumblebee (Bombus pascuorum) where traditional recording scheme data held by NBN were patchy, both across the UK and over time, reflecting active record centres rather than species distribution.

Non-expert citizen science records displayed more extensive geographic coverage, reflecting human population density.

We recommend, where possible, complementing skilled naturalist recording with non-expert citizen science programmes to obtain a nation-wide capability, and stress the need for timely uploading of data to the national repository.

BeeWatch records compared against OPAL data

Tree Bumblebee facts

  1. The Tree Bumblebee (Bombus hypnorum) was first recorded in 2001 in Wiltshire.  
  2. Since then it has spread dramatically. It can be found in many areas of England and Wales, and has also been recorded more recently in the Central Belt of Scotland.
  3. The Tree Bumblebee is visually distinct from our native species and is characterised by a black head, ginger/brown thorax and a white tail.  
  4. It is very much a species of urban gardens now and is frequently recorded nesting in bird boxes. 
  5. Numbers are highest in late May and early June.

Find out more

If you would like to learn more about bumblebees then visit:

If you are not sure what species are visiting your gardens, then take a picture and submit it to:

Here you can use an online guide to help you identify your species. One of their experts will review your submission and confirm or complete the identification, also providing feedback to you on what visual features are important to identify it.

Read the full research paper summarised in this article, at:

  • van der Wal, R., Anderson, H., Robinson, A., Sharma, N., Mellish, C., Roberts, S., Darvill, B. and Siddharthan, A., 2015. Mapping species distributions: A comparison of skilled naturalist and lay citizen science recording. Ambio44(4), pp.584-600. DOI:10.1007/s13280-015-0709-x

​​Photo credits: Tree Bumblebee on Marjoram by Nigel Jones, CC BY-NC-ND 2.0