D5: Conservation status of our native species

Short Description

This indicator will track changes in the national extinction risk faced by terrestrial, freshwater and marine species using the International Union for Conservation of Nature’s (IUCN) Red List categories and criteria (Version 3.1 Second edition, 2000). The Red-listing process classifies each species into one of 11 categories including Least Concern, Near Threatened, Vulnerable, Endangered, Critically Endangered, Regionally Extinct, Extinct in the Wild and Extinct. Species classified as Vulnerable, Endangered and Critically Endangered are defined as ‘threatened’ with extinction. A simple Red List Index will be used to summarise the changes in numbers of species between each category over time.

Readiness and links to data

The IUCN red-listing process uses 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 (Extinct, Extinct in the Wild, Regionally Extinct, Critically Endangered, Endangered, Vulnerable, Near Threatened and Least Concern) and how these numbers change over time as 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. In this way, the index can be used to measure overall extinction risk of a large number of species at a specific point in time, and when recalculated at intervals, to provide a trend.

The ‘Red List Index for England’, presented here for the first time, includes all species (taxa) native to England that appear in approved Great Britain IUCN Red Lists, and for which a Red List Category is available (excluding Data Deficient, Not Applicable, Not Evaluated and globally Extinct). It encompasses the status of 8,259 taxa across 23 major taxonomic groups, but focusses almost exclusively on terrestrial and freshwater taxa, comprising: 49% invertebrates’ 29% vascular plants, mosses and liverworts; 18% fungi and lichens; and 4% vertebrates. Assuming a total of approximately 40,000 native macro-species in terrestrial and freshwater groups in England, about 20% are covered by the index.

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 and we anticipate the indicator operating 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.

Further details on the development of the Red List Index for England together with supporting data and a species list are available in the Natural England research report 124 while information on the derivation of a Red List Index is available on 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’.

Indicator components

Figure D5: Red List Index for England by broad taxonomic group, 2022 baseline

Table D5: 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 D5

The aggregate value of the Red List Index for England for the baseline year of 2022 is 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.

Indicator Metadata