Table 1. Parameters used to test sensitivity of ranks-to-extinction probability transformations.
| Extinction Probabilities | ||||||
| IUCN Category | % tips1 | Isaac2 | IUCN1003 | IUCN504 | IUCN5004 | Pessimistic |
| Least Concern | 76 | 0.025 | 0.0001 | 0.00005 | 0.0005 | 0.2 |
| Near Threatened | 9 | 0.05 | 0.01 | 0.004 | 0.02 | 0.4 |
| Vulnerable | 9 | 0.1 | 0.1 | 0.05 | 0.39 | 0.8 |
| Endangered | 4 | 0.2 | 0.667 | 0.42 | 0.996 | 0.9 |
| Critically Endangered | 2 | 0.4 | 0.999 | 0.97 | 1 | 0.99 |
1
Mean proportions of species in each IUCN category across birds and mammals.
2
Inferred from [12], using the IUCN designation of Prob(ext)VU = 0.1 in 100 years.
3
Projected Prob(extinction) at 100 years using IUCN designations (IUCN, 2001): Prob(ext)CR = 0.5 in 10 years; Prob(ext)EN = 0.2 in 20 years; Prob(ext)vu = 0.1 in 100 years. LC and NT categories interpolated; see methods.
4
IUCN designations projected to 50 or 500 years.