Red Listing and Indicators

Current Activity

In the past, species’ status was often assessed on expert opinion, or by counting the number of occupied grid cells. Our recent work has used computer simulations of the recording process to inform how we can estimate the trends in species status over decadal timescales. BRC is working with recording schemes, government agencies and partner organisations to derive quantitative trend estimates and other metrics for use in Red Listing and the development of biodiversity indicators to assess the 2020 ‘Aichi targets’.

Key Outputs

Building upon earlier atlases, trend estimates were presented in recent atlases for ladybirds (2011), hoverflies (2011), dragonflies (2014) and bryophytes (2014).  We continue to work with recording scheme experts to extend the availability of trend information to a much wider set of species groups.  The State of Nature Reports (2013 & 2019) to which BRC contributed trends for over 1,000 species, highlighted declines in UK wildlife. The Priority Species Indicator tracks changes in the status of over 200 species of conservation concern.

Growth in threatened species status assessments

Growth in species over time

Figure: Nick Isaac, CEH.

The cumulative number of UK taxa (species and subspecies) that have been formally assessed against criteria for conservation prioritisation.

Provisional extinction risk assessment of 1026 species using biological records.

Proportions of species in extinction categories

Figure: Nick Isaac, CEH

Species were assessed against IUCN criterion A2c, based on rates of decline in frequency of occurrence since 2000. The categories are Critically Endangered (CR: >80% decline), Endangered (EN: >50%), Vulnerable (VU: >30%), Near Threatened (NT: >20%) and Least Concern (LC: stable or increasing).

The Priority Species Indicator, using biological records

Cover of UK Biodiversity Indicators in Your Pocket

Photo: © JNCC

For the first time in 2013, the UK Government published a biodiversity indicator based solely on opportunistic biological records data. The indicator included ~230 insects (mostly moths & bees) listed as conservation priorities by the four national governments of the UK.

Future Challenges

Sophisticated statistics make it possible to estimate quantitative measures of species’ trends (IUCN criterion A) and range size (criterion B) using biological records. In doing so, these models make a number of assumptions about how the data are collected.  As analytical tools become more widely adopted, our challenge is to harmonize how criteria are applied across taxa and regions.  Clear guidelines are needed to resolve conflicts between model results and expert opinion in order to provide robust species trend information.




Powney Gary D., Carvell Claire, Edwards Mike, Morris Roger K. A., Roy Helen E., Woodcock Ben A., Isaac Nick J. B. (2019) Widespread losses of pollinating insects in Britain. ,
Van Swaay C.A.M., Dennis E.B., Schmucki R., Sevilleja C., Balalaikins M., Botham M., Bourn N., Brereton T., Cancela J.P., Carlisle B., Chambers P., Collins S., Dopagne C., Escobes R., Feldman R., Fernandez-Garcia J.M., Fontaine B., Gracianteparaluceta A., Harrower C., Harpke A., Heliola J., Komac B., Kuhn E., Lang A., Maes D., Mestdagh X., Middlebrook I., Monasterio Y., Munguira M.L., Murray T.E., Musche M., Ounap E., Paramo F., Petterson L.B., Piqueray J., Settele J., Stefanescu C., Svitra G., Tiitsaar A., Verovnik R., Warren M.S., Wynhoff I., Roy D.B. (2019) The EU Butterfly Indicator for Grassland species: 1990-2017. Technical report. Butterfly Conservation Europe, Wageningen, The Netherlands
Woodcock B. A., Garratt M. P. D., Powney G. D., Shaw R. F., Osborne J. L., Soroka J., Lindström S. A. M., Stanley D., Ouvrard P., Edwards M. E., Jauker F., McCracken M. E., Zou Y., Potts S. G., Rundlöf M., Noriega J. A., Greenop A., Smith H. G., Bommarco R., van der Werf W., Stout J. C., Steffan-Dewenter I., Morandin L., Bullock J. M., Pywell R. F. (2019) Meta-analysis reveals that pollinator functional diversity and abundance enhance crop pollination and yield. ,
Mathews Fiona, Harrower Colin (2020) IUCN-compliant Red List for Britain's Terrestrial Mammals. Assessment by the Mammal Society under contract to Natural England, Natural Resources Wales and Scottish Natural Heritage. Natural England,
Mathews Fiona, Smith Bethany, Harrower Colin, Coomber Frazer (2020) The State of Mammals in Wales. A report by the Mammal Society for Natural Resources Wales. The Mammal Society,
141 (1977) British Red Data Book, volume 1: Vascular Plants. Society for the Promotion of Nature Conservation, Lincoln
142 Burns F., Eaton Mark A, Gregory R.D., Fulaij Al, August T.A., Biggs J., Bladwell S., Brereton Tom M., Brooks D.R., Clubbe C., Dawson J., Dunn E., Edwards B., Falk S.J., Gent T., Gibbons D.W., Gurney M., Haysom K.A., Henshaw S., Hodgetts N.G., Isaac Nick J. B., McLaughlin M., Musgrove Andrew J., Noble David G., O’Mahony E., Pacheco M., Roy D. B., Sears J., Shardlow M., Stringer C., Taylor A., Thompson P, Walker Kevin J., Walton P., Willing M.J., Wilson J., Wynde R. (2013) State of Nature report. The State of Nature partnership,
145 (2013) C4. Status of threatened species. JNCC,
359 Perring Franklyn H., Farrell Lynne (1983) British Red Data Book, volume 1: Vascular Plants. Royal Society for the Conservation of Nature, Lincoln
360 Wigginton M.J. (1999) British Red Data Books: 1 Vascular plants (3rd edition).. Joint Nature Conservation Committee, Peterborough