D5: Conservation status of our native species
Short Description
This indicator will track changes in the national extinction risk faced by terrestrial and freshwater species. It will do this by using the International Union for Conservation of Nature’s (IUCN) Red List categories and criteria (Version 3.1 Second edition, 2012). The Red-listing process, when applied to countries, classifies each species into one of several categories including Least Concern, Near Threatened, Vulnerable, Endangered, Critically Endangered, Regionally Extinct (country scale), Extinct in the Wild (global scale) and Extinct (global scale). Species classified as Vulnerable, Endangered and Critically Endangered are defined as ‘threatened’ with extinction. The indicator summarises the IUCN Red List category of a large number of species through a ‘Red List Index’, the value of which decreases as species become more threatened and increases as species become less threatened.
Readiness and links to data
The presentation of extinction risk for this indicator is split into 2 parts. Component D5i presents the aggregate value of the 'Red List Index for England' and the individual index values for 36 taxonomic groups. Component D5ii presents a summary by extinction risk category of the same data. It shows the percentage of 8,259 native species (taxa) in the Red List Index for England that are classified as falling into each of the main extinction risk categories, together with the percentage considered to be threatened. Therefore, D5ii represents a snapshot of the status of species in the baseline index in 2022.
Further details on the development of the Red List Index for England, along with supporting data and a species list are available in the Natural England research report 124, while information on the methodology of a Red List Index is available on the IUCN website. Additional detail on extinction risk categories is also available on the Regional Red List Assessments page of the IUCN website.
Available data on changes in abundance and distribution of native species are presented in indicators ‘D4 Relative abundance and/or distribution of widespread species’, ‘D6 Relative abundance and/or distribution of priority species’ and ‘D7 Species supporting ecosystem functions’.
Notes on indicator
The IUCN red-listing process is a globally accepted methodology for assessing species extinction risk at global and regional (including national) scales.
A Red List Index is based on the numbers of species in each Red List category. How these numbers change over time reflects how species improve or deteriorate in status. The index is expressed as a value between zero and one, where ‘one’ equates to all species assessed as Least Concern (hence none are expected to go extinct in the near future), and ‘zero’ indicates that all species have gone extinct within the geographical area being considered. In this way, the index is used to measure the overall extinction risk of many species, and when recalculated at intervals, this provides a trend.
The Red List Index for England encompasses the status of 8,259 species native to England for which a Great Britain Red List Category was available in 2022 (excluding species classed as Data Deficient, Not Applicable, Not Evaluated and globally Extinct). Under IUCN guidance, micro-organisms are unsuitable for Red List assessment, hence the index focusses on macro-organisms which are defined here as of sufficient size to be seen by the human eye unaided. The index covers 23 major taxonomic groups, comprising almost exclusively terrestrial and freshwater taxa: 49% invertebrates; 29% vascular plants, mosses and liverworts; 18% fungi and lichens; and 4% vertebrates. Assuming a total of approximately 40,000 native macro-organisms (species) in terrestrial and freshwater groups in England, about 20% are covered by the index.
Great Britain scale assessments can underestimate or overestimate extinction risk at an England scale. A comparison of Great Britain and England Red List categories across 4 taxonomic groups showed that between 80% to 92% of statuses aligned and therefore the Red List Index presented here is considered an approximation of extinction risk in England. Importantly, losses from England of species still present in Scotland or Wales will not be detected by the index. In future updates of this indicator, geographical biases to gains and/or losses will be reviewed, and losses from England as a whole highlighted.
The indicator presented here excludes changes in the number of species in each Red List category that are driven by improvements in knowledge (e.g. increase in data) or changing taxonomy, rather than a real change in population or distribution. It therefore measures genuine improvements or deteriorations in the status of species.
Change in the Red List Index for England is expected to be subtle, partly because it is numerically dominated by species of Least Concern, and the index measures net changes in the movement of species between Red List categories. Furthermore, the index can exhibit time-lags, due to the implementation of biodiversity policies, resultant improvements in species populations, available data evidencing these and the frequency of Red List assessment. Therefore, the index will be most effective as a long-term indicator. It is anticipated that the indicator will operate over at least a 20-year period (2022 to 2042), with a 10-year update cycle of every Great Britain Red List in the index. The D5 indicator will be partially updated and reported on every 5 years.
Indicator components
Figure D5i: Red List Index for England by broad taxonomic group, 2022 baseline
Table D5i: Red List Index for England by broad taxonomic group, 2022 baseline
| Red List Index group | Value |
|---|---|
| Butterflies | 0.74 |
| Birds | 0.74 |
| Amphibians and reptiles | 0.77 |
| Scarab beetles and allies | 0.78 |
| Mammals (non-marine) | 0.82 |
| Dragonflies and damselflies | 0.83 |
| Freshwater Fish | 0.84 |
| Bolete fungi | 0.84 |
| Clown and False-clown beetles | 0.85 |
| Shield bugs and allies | 0.86 |
| Longhorn beetles | 0.88 |
| Carrion beetles | 0.88 |
| Wood boring beetles and allies | 0.88 |
| Leaf beetles and allies | 0.89 |
| Grasshoppers, crickets and allies | 0.89 |
| Darkling beetles and allies | 0.89 |
| Mayflies | 0.90 |
| Soldier beetles and allies | 0.90 |
| Ground beetles | 0.90 |
| Soldier flies and allies | 0.90 |
| Vascular plants | 0.90 |
| Water beetles | 0.91 |
| Spiders | 0.91 |
| Aggregate | 0.91 |
| Mosses and liverworts | 0.92 |
| Lichens | 0.93 |
| Caddisflies | 0.94 |
| Molluscs (non-marine) | 0.94 |
| Rove beetles (macrostaphs) | 0.94 |
| Spear-winged and Flat-footed flies | 0.94 |
| Long-legged flies | 0.94 |
| Stoneflies | 0.95 |
| Pill beetles and allies | 0.96 |
| Rove beetles (tachyporines) | 0.96 |
| Water bugs | 0.97 |
| Millipedes, centipedes and woodlice | 0.97 |
| Hoverflies | 0.97 |
Trend description for D5i
The aggregate value of the Red List Index for England for the baseline year of 2022 was 0.9070, while the index values for individual groups ranged from 0.7387 to 0.9747, with a median of 0.8979. Butterflies; birds; and amphibians and reptiles had the lowest Red List Index values (highest extinction risk) of 0.7387, 0.7448 and 0.7692 respectively, while hoverflies; millipedes, centipedes and woodlice; and water bugs had the highest values (lowest extinction risk) of 0.9747, 0.9689 and 0.9651 respectively.
Assessment of change
No assessment of change was undertaken for this indicator as a suitable time series is not yet available in the Outcome Indicator Framework.
Figure D5ii: Percentage of species in the 2022 baseline Red List Index for England by category of extinction risk
Table D5ii: Percentage of species in the 2022 baseline Red List Index for England by category of extinction risk
| Red List Index category | Percentage |
|---|---|
| Threatened Categories | 12.04 |
| Extinct | 1.78 |
| Critically Endangered | 1.95 |
| Endangered | 3.66 |
| Vulnerable | 6.43 |
| Near Threatened | 5.98 |
| Least Concern | 80.20 |
Trend description for D5ii
In the 2022 baseline year, of the 8,259 native species (taxa) in the Red List Index for England, 1.8% were either Extinct (in Great Britain), Regionally Extinct, Extinct in the Wild or Critically Endangered (Possibly Extinct), 12% were considered to be in one of the 3 threatened categories (1.9% Critically Endangered, 3.7% Endangered and 6.4% Vulnerable) and a further 6% were considered to be Near Threatened. The remaining 80% of the species in the index were categorised as 'Least Concern' in this baseline assessment. Note that Least Concern species can be in decline but not at a rate, or to a degree, sufficient to be considered at risk of extinction.
Assessment of change
No assessment of change was undertaken for this indicator as a suitable time series is not yet available in the Outcome Indicator Framework.