Red List Criteria: Criterion A

1. Red List Criteria: Criterion A

2. Population Size Time Past, present or future population reduction

3. Population Size Time 3 generations or 10 years (whichever is the longer) To use criterion A, we first need to know: What is the generation length? Or is it likely that a three generation time period is less than 10 years?

4. Based on any of four criteria: * Up to a maximum of 100 years into the future

6. Example: a whale • Generation length ~ 31 years • Population decline 70-90% over past 3 generations. Populations appear to be recovering. • Population declines caused by commercial whaling: • Cause and effects of decline is fully understood • Commercial whaling has stopped • Pop decline appears to be reversible • Percentage decline based on: • Whale sightings and observations • Stock monitoring surveys and reports • Whaling statistics and records • Given uncertainty in the decline and current stability and population recovery, is listed as EN. CR/EN A1 CR/EN A1a CR/EN A1b CR/EN A1d EN A1abd

7. Example: a tree • Generation length unknown; ~ 50 years in similar species • Endemic to dry forest, which have been intensively cut for agriculture over last century. Today only highly fragmented forest patches remain, and suffer: • Intense predation from deer and cattle • Uncontrolled fires • Estimated 95% habitat loss over past 150 years: given population densities & distribution, suspected population decline of at least 50%. • Habitat loss ongoing. Regeneration close to zero due to intensive grazing; seeds also consumed by butterfly larvae – suspected population decline of up to 80% over next 100 years. • Population decline rate based on: • Massive habitat loss • Introduced predators EN A2 CR/EN A3 A2+3c A2+3e EN A2+3ce

8. Near Threatened (NT) example: Should be close to meeting the VU thresholds or possibly meet some of the subcriteria • Population has declined by 40% in the last three generations • Causes of decline are understood, the causes have stopped, and the decline is reversible. • NT , nearly meeting VU A1 • Population has declined by 20-25% in the last three generations • Causes of the decline are not understood and appear to be ongoing (i.e. the population is still declining) • NT, nearly meeting VU A2

9. 10 years / 3 generations 10 years / 3 generations 10 years / 3 generations Present Criterion A4past & future: “shifting time window”

10. Present Criterion A4past & future: “shifting time window” If a “moving-window” reduction cannot be calculated over the full time series: Reliable data available Most confident 10 year / 3 generation time period

11. Points to remember: To use criterion A, an estimate of the generation length is needed 3 generations? 10 years? Population reduction may be a one-off event... ... Or it may be ongoing

12. Points to remember: Criterion A1 uses higher thresholds than A2, A3 and A4

13. Points to remember: A3 = projected FUTUREreduction so cannot be based on direct observation (A3a)

14. Points to remember: Consider the pattern of population reduction

15. Refer to User Guidelines and ‘CriterionA.xls’ for information and advice