EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Species distribution models fail to predict paleozoological occurrences during the Holocene Green Sahara phase

Ignacio Lazagabaster1,2, Juliet Spedding3, Irene Solano-Regadera1, Chris Thomas4, Salima Ikram5, Severus Snape3, and Jakob Bro-Jorgensen1
Ignacio Lazagabaster et al.
  • 1University of Liverpool, Department of Ecology and Behaviour, Liverpool L69 3BX, United Kingdom
  • 2Centro Nacional de Investigacion Sobre Evolucion Humana, CENIEH, Burgos 09002, Spain
  • 3University of Liverpool, Department of Archaeology, Classics and Egyptology, Liverpool L69 3BX, United Kingdom
  • 4University of York, Department of Biology and Leverhulme Centre for Anthropocene Biodiversity, York YO10 5DD, United Kingdom
  • 5The American University in Cairo, Department of Sociology, Egyptology and Anthropology, New Cairo 11835, Egypt

Paleoclimatic simulations are powerful tools to investigate past faunal biogeographical patterns, but they can fail to capture complex climatic conditions at specific regional or temporal scales. Here we show that species distribution models (SDMs) do not predict the expansion of suitable habitats for mammals that were present in the Sahara during the African Humid Period (AHP) according to radiocarbon-dated paleozoological records. We illustrate this issue by modeling the current and past distribution of the hartebeest (Alcelaphus buselaphus), a typical African savanna antelope with a wide Sub-Saharan distribution. Its Holocene paleozoological record shows that its distribution during the AHP included large areas of the Sahara and the northern African Mediterranean coast, from Morocco to Egypt and the Levant. We use Bayesian additive regression trees (BARTs) with an MCMC algorithm in combination with current climate and occurrence data to generate posterior distributions of habitat suitability, evaluate variable importance, and generate variable partial-dependence plots. From these, we learn that annual precipitation is the most important climatic variable determining the hartebeest’s current distribution. We then projected habitat suitability onto various paleoclimatic scenarios during the AHP and found that the estimated precipitation did not reach the minimum required for the viability of hartebeest populations. These results highlight the potential of the fossil record to test the regional precision of paleoclimatic simulations, ultimately helping to generate more realistic past environmental scenarios.

How to cite: Lazagabaster, I., Spedding, J., Solano-Regadera, I., Thomas, C., Ikram, S., Snape, S., and Bro-Jorgensen, J.: Species distribution models fail to predict paleozoological occurrences during the Holocene Green Sahara phase, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-16871,, 2023.

Supplementary materials

Supplementary material file