Past environmental changes affected lemur population dynamics prior to human impact in Madagascar

Helena Teixeira,Ute Radespiel,Sylvie Rouland,Lounès Chikhi,Laurent Bremond,Vincent Montade,Gerhard Daut,Romule Rakotondravony,Thomas Kasper,Hermann Behling,Jordi Salmona,Julia Metzger,Sandratrinirainy Ranarilalatiana

doi:10.1038/s42003-021-02620-1

Abstract

Quaternary climatic changes have been invoked as important drivers of species diversification worldwide. However, the impact of such changes on vegetation and animal population dynamics in tropical regions remains debated. To overcome this uncertainty, we integrated high-resolution paleoenvironmental reconstructions from a sedimentary record covering the past 25,000 years with demographic inferences of a forest-dwelling primate species (Microcebus arnholdi), in northern Madagascar. Result comparisons suggest that climate changes through the African Humid Period (15.2 – 5.5 kyr) strongly affected the demographic dynamics of M. arnholdi. We further inferred a population decline in the last millennium which was likely shaped by the combination of climatic and anthropogenic impacts. Our findings demonstrate that population fluctuations in Malagasy wildlife were substantial prior to a significant human impact. This provides a critical knowledge of climatically driven, environmental and ecological changes in the past, which is essential to better understand the dynamics and resilience of current biodiversity.

Highlights

Quaternary climatic changes have been invoked as important drivers of species diversification worldwide
Our result comparisons demonstrate that the demographic dynamics of M. arnholdi were exclusively shaped by natural climate changes until the late Holocene, whereas the dynamics during the last millennium were likely shaped by both natural climate and anthropogenic changes
Granulometric properties as well as a Principal Component Analysis (PCA) of the X-Ray fluorescence (XRF) data, our results unveil five distinct periods of different climatic conditions associated with different plant assemblages (Fig. 2 and Supplementary section 1.1–1.4): a first period (25–15.2 kyr) with cold and dry conditions, a second and third period (15.2–11.8 and 11.8–5.5 kyr) related to increased humidity and temperature during the African Humid Period (AHP), a fourth period (5.5–0.9 kyr) characterized by

Summary

Introduction

Quaternary climatic changes have been invoked as important drivers of species diversification worldwide. The impact of such changes on vegetation and animal population dynamics in tropical regions remains debated To overcome this uncertainty, we integrated high-resolution paleoenvironmental reconstructions from a sedimentary record covering the past 25,000 years with demographic inferences of a forest-dwelling primate species (Microcebus arnholdi), in northern Madagascar. The inferred demographic dynamics were compared and integrated with paleoenvironmental reconstructions that were derived from a continuous sediment record from Lac Maudit, located at the center of the NP in the evergreen humid forest (1250 m asl Fig. 1a) and less than 6 km away from either mouse lemur site Such a dual paleoecological–genomic approach that compares genomic a b. Our study illuminates how natural climate fluctuations and anthropogenic activities impacted Malagasy wildlife across time and provides a critical understanding of biological responses of forest-dwelling species to ongoing and accelerating climate change

Methods

Results

Conclusion