A deadly cocktail

How a drought around 4200 cal. yr BP caused mass mortality events at the infamous ‘dodo swamp’ in Mauritius

Bibliographic Data

ID12266425
AuthorsErik J de Boer (0000-0002-7157-9860, University of Amsterdam, corresponding author), Maria I Velez (0000-0003-2990-6343, University of Regina), Kenneth F Rijsdijk (0000-0002-0943-2577, Computational GeoEcology Group, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, The Netherlands), Perry Gb de Louw (Deltares, The Netherlands), Tamara Vernimmen (Naturalis Biodiversity Center), Tamara JJ Vernimmen (Sector Botany, Naturalis Biodiversity Center, The Netherlands), P Visser (0000-0003-3294-1908, University of Amsterdam), Petra M Visser (University of Amsterdam), Rik Tjallingii (0000-0002-9723-3622, Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum, Germany), Henry Hooghiemstra (0000-0003-2502-1644, University of Amsterdam)
Year2015
Volume25
Issue5
Pages758-771
Publication date2015-01-16
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueThe Holocene (JOURNAL)
Journal identifiersISSN: 0959-6836 • E-ISSN: 1477-0911
PublisherSAGE Publishing (PUBLISHER • US)
DOI10.1177/0959683614567886
OpenAlexW2008334042
LanguageEN
Citations received1
References cited56

Analyses of pollen, diatoms, XRF geochemistry, and pigments provide a unique window into how an insular ecosystem in Mauritius responded to an extreme drought event 4200 years ago. We provide a reconstruction of regional vegetation change and local wetland development under influence of sea level rise and inferred climate change between 4400 and 4100 cal. yr BP. Our multi-proxy data evidence a severe drought between 4190 and 4130 cal. yr BP, which ultimately led to mass mortality of larger vertebrates, including two species of giant tortoises and dodos in a <2-ha region. This prolonged drought around the Indian Ocean is recorded in many regions dependent on monsoon precipitation and is suggested to cause the collapse of human societies in East Africa and India. We demonstrate a direct relation between the mass mortality events in the Mare aux Songes (MAS) rock valley and the 4200 cal. yr BP drought. MAS represents a fresh water source that attracted and concentrated vertebrates. Abrupt increased aridity induced regional fires on Mauritius and caused decreased water levels, and a shrinking water surface resulting in further concentration of the animals in this coastal site. Upconing of the saline wedge underlying the fresh water source induced progressive salinization. The excrements of the animals produced hypertrophic conditions that, combined with salinization and high temperatures, created a suitable environment for potentially toxic cyanobacteria. These factors led to a deadly cocktail, resulting in the death of 100,000s of vertebrates by intoxication, dehydration, trampling, and miring, and promoted a unique conservation of fossils. The ‘4.2 ka megadrought’ likely induced similar bottlenecks elsewhere in the SW Indian Ocean region

Arid · Biology · Ecosystem · Geography · Monsoon · Physical geography · Wetland · Geology and Paleoclimatology Research · Isotope Analysis in Ecology · Maritime and Coastal Archaeology · Ecology · Geology · Oceanography