Improving generation length estimates for the IUCN Red List

January 22, 2018

Robert S. C. Cooke1,2,4, Tania C. Gilbert2,4, Philip Riordan2,4 & David Mallon3,4

1University of Southampton, 2Marwell Wildlife, 3Manchester Metropolitan University, 4IUCN SSC Antelope Specialist Group

The International Union for the Conservation of Nature (IUCN) Red List classifies species according to their risk of extinction, informing local to global conservation decisions. It is the world’s most comprehensive inventory of the global conservation status of biological species. A key consideration in determining extinction risk is our understanding of the generation lengths of species. For example, species with longer generation lengths might be less able to respond rapidly to human-induced changes to their environments. These are not known for all, or even most species, which impedes our ability to fully describe true extinction risk. In January we published a paper in PLOS One that looked to advance the estimation of generation lengths, using antelope as an example group. We calculated or predicted generation length for 86 species of antelope, and tested the importance of both body-mass and phylogeny (genetic relatedness) as predictors of generation length. We showed that captive and wild data for longevity produced different results respectively, and that both body-mass and phylogeny were both important predictors for generation length. 

Our model had good predictive power and could be used to extrapolate generation length to missing-data species, making the results of our research more widely applicable. We advised treating captive and wild data separately when estimating generation length, and recommended that Red List assessors carefully consider the relative implications of using wild and captive data in life-history analyses. We also recommended that body-mass and phylogeny should be used in combination to extrapolate generation length to missing-data species. Overall, we provided a transparent, consistent and transferable approach for improving estimates of generation length with direct application to IUCN Red List assessments. We anticipate that this can help increase the accuracy of Red List assessments, especially when detailed life-history data are missing. 

For further information, please go to PLOS One to read the abstract or download the paper 

Citation: Cooke, R.S.C., Gilbert, T.C., Riordan, P. & Mallon, D (2018) Improving generation length estimates for the IUCN Red List. PLoS ONE 13(1): e0191770.