Table 3.
Total number of species per demographic measure or rate by taxonomic class
| Demographic measure or rate | No. of species and percentage of species (%) | |||
| Fertility | Reptilia | Mammalia | Aves | Amphibia |
| Age at first reproduction | 758 (7.7) | 1,977 (35.4) | 1,279 (12.4) | 199 (3.1) |
| Interlitter/interbirth interval | 62 (0.6) | 1,167 (21.0) | 75 (0.7) | 2 (0) |
| Litter/clutch size | 3,340 (34.1) | 3,364 (60.3) | 6,652 (64.4) | 711 (11.0) |
| Proportion of reproductive females | 0 (0) | 0 (0) | 44 (0.4) | 0 (0) |
| Recruitment | 0 (0) | 0 (0) | 22 (0.2) | 0 (0) |
| Age- or stage-specific fertility rates | 37 (0.4) | 137 (2.5) | 248 (2.4) | 10 (0.2) |
| Survival | ||||
| Maximum recorded life span | 1,430 (14.6) | 2,572 (46.0) | 1,641 (15.9) | 226 (3.5) |
| Mean age of (adult) population | 0 (0) | 0 (0) | 0 (0) | 114 (1.8) |
| Crude mortality | 103 (1.1) | 236 (4.2) | 808 (7.9) | 22 (0.3) |
| Age- or stage-specific death rate | 38 (0.4) | 220 (4.0) | 343 (3.3) | 12 (0.2) |
The relative number of species per taxonomic class for which that measure exists is indicated in parentheses. Further information about measures of knowledge for the Demographic Species Knowledge Index is provided in Methods .