Metric permalink

Wild bird populations (decline since 1970)

Official

Part of the Environment and Climate domain. Decline in the UK all-species wild bird index since the 1970 baseline (130 breeding species).

Latest data

Latest reading

Latest value
18% decline since 1970

2024

Previous value
18% decline since 1970
no change

Change between the two latest observations (2024 to 2024), in stress score.

Direction of badnesshigher is worse

A higher reading is treated as worse for this indicator.

Score composition

Stress score

51/100

Since the August 2026 release

no changefrom 51 to 51

Nothing changed on this indicator between the two releases: no new observation, revision, restatement or source change, and its stress score did not move.

Blended from two measured components: (2/3 weight) and trend (1/3 weight); where no trend can be computed the metric is scored on its level alone. Volatility is published as a diagnostic and does not enter the blend. Full formula on the methodology page.

Level · 2/3 weight

51bounds

Bounds: scored against fixed best/worst limits, used until a metric has about eight years of verified data to rank against.

Trend · 1/3 weight

50stable

Neutral: the latest reading matches the one before it, so no change is measured.

Volatility · diagnostic, not blended

50

Provisional: fewer than four historical readings are available, so this defaults to a mid range score rather than a measured figure.

Data confidence and provenance

Confidence and source

0.85High0.85

How much weight to put on the reading, the mean data-confidence across the component metrics (source quality, recency and completeness).

Source

Department for Environment, Food and Rural AffairsOfficial

DEFRA: Wild bird populations in the UK

Update frequency
Annual
Reliability
high
View source series ↗

Provenance

Provider
DEFRA
Series ID
defra_wild_birds
Frequency
Annual
Accessed
16 June 2026

Known weakness

Stored as % decline from 1970; the full annual index is in the DEFRA dataset. Down 4% over 2019–2024.

Notes

Verified official value from DEFRA (defra_wild_birds), accessed 2026-06-16.

Historical values

History

PeriodValueRelative
202418