Onset of summer aridification and the decline of Homo floresiensis at Liang Bua 61,000 years ago

Abstract The cause of the disappearance of the primitive hominin Homo floresiensis from the Indonesian island of Flores about 50,000 years ago is a key question in palaeoanthropology. While the potential roles of climate change and human agency continue to be debated, the history of freshwater availability essential for survival at the type locality, Liang Bua, remains poorly understood. Although speleothem δ 18 O is widely used to reconstruct monsoon rainfall, variations in summer and winter rainfall, with distinct δ 18 O values, can complicate interpretations of mean annual rainfall. Here, we combine speleothem Mg/Ca, a proxy for local rainfall, with δ 18 O to determine annual, summer and winter rainfall amounts concurrent with H. floresiensis and Stegodon , one of its primary prey. Geochemical modelling of the Mg- 18 O system reveals a sustained decline in mean annual rainfall from ~1560 to 990 mm between 76,000 and 61,000 years ago. Critically, summer rainfall decreased to a record low of ~450 mm at 61,000–55,000 years ago, alongside a marked decline in both the abundance and relative proportion of Stegodon remains in the fossil record. These findings increase the likelihood that progressive landscape aridification, and intensified human-faunal competition for dwindling resources, culminated in abandonment of Liang Bua.

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Publication Details

Journal
Communications Earth & Environment
Published
2025-12-08
DOI
https://doi.org/10.1038/s43247-025-02961-3
Citations
3
Primary Topic
Pleistocene-Era Hominins and Archaeology
Type
article
Field-Weighted Citation Impact
34.04

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article

Onset of summer aridification and the decline of Homo floresiensis at Liang Bua 61,000 years ago

R. Lawrence Edwards, Garry K. Smith, Hai Cheng, John Hellström et al.
3 citations
Communications Earth & Environment
Pleistocene-Era Hominins and Archaeology
34.04
article

Onset of summer aridification and the decline of Homo floresiensis at Liang Bua 61,000 years ago

R. Lawrence Edwards, Garry K. Smith, Hai Cheng, John Hellström, Jian‐xin Zhao, Heather Scott‐Gagan, Hamdi Rifai, Bambang W. Suwargadi, Gerrit D. van den Bergh, Bronwyn Dixon, Joan Cowley, Alena Kimbrough, Wahyoe S. Hantoro, Nick Scroxton, Scott A. Condie, Linda K. Ayliffe, Michael K. Gagan, Mika Rizki Puspaningrum, Henri Wong, Neil L. Anderson
article en
3 citations

Abstract

Abstract The cause of the disappearance of the primitive hominin Homo floresiensis from the Indonesian island of Flores about 50,000 years ago is a key question in palaeoanthropology. While the potential roles of climate change and human agency continue to be debated, the history of freshwater availability essential for survival at the type locality, Liang Bua, remains poorly understood. Although speleothem δ 18 O is widely used to reconstruct monsoon rainfall, variations in summer and winter rainfall, with distinct δ 18 O values, can complicate interpretations of mean annual rainfall. Here, we combine speleothem Mg/Ca, a proxy for local rainfall, with δ 18 O to determine annual, summer and winter rainfall amounts concurrent with H. floresiensis and Stegodon , one of its primary prey. Geochemical modelling of the Mg- 18 O system reveals a sustained decline in mean annual rainfall from ~1560 to 990 mm between 76,000 and 61,000 years ago. Critically, summer rainfall decreased to a record low of ~450 mm at 61,000–55,000 years ago, alongside a marked decline in both the abundance and relative proportion of Stegodon remains in the fossil record. These findings increase the likelihood that progressive landscape aridification, and intensified human-faunal competition for dwindling resources, culminated in abandonment of Liang Bua.

Communications Earth & EnvironmentVol. 6(1)
Australian National University (AU), CSIRO Oceans and Atmosphere (AU), University of Minnesota (US), Australian Nuclear Science and Technology Organisation (AU), Bandung Institute of Technology (ID), National University of Ireland, Maynooth (IE), The University of Queensland (AU), The University of Melbourne (AU), Indonesian Institute of Sciences (ID), Chinese Academy of Sciences (CN), University of Wollongong (AU), State University of Padang (ID), Institute of Earth Environment (CN), Xi'an Jiaotong University (CN)
National Science Foundation, University of Wollongong, National Natural Science Foundation of China, Lembaga Ilmu Pengetahuan Indonesia, Japan Agency for Marine-Earth Science and Technology
Openalex Percentile: Top 0%
Pleistocene-Era Hominins and Archaeology
34.04
DOIOpen Access PDFOpenAlex
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