image: Author David Steadman screen washing fossil-filled sediment. Marsh Harbor, Abaco, The Bahamas. view more
Credit: Image credit: Janet Franklin
A fossil analysis charting the presence of bird species in the islands of the Bahamian archipelago over recent millennia finds altered current distributions for 69% of the land bird species. Humans arrived in the Bahamas around 1,000 years ago, and prehistoric climate shifts have altered habitats, especially the transition from the relatively cool and dry Pleistocene epoch to the current warm and wet Holocene epoch. However, the influence of such factors on the biodiversity of the islands' bird species is unclear. David W. Steadman and Janet Franklin report that 69% of land bird species in the Pleistocene fossil record have currently different distributions. The authors charted species composition over time in four fossil sites across four islands in the Bahamian archipelago. Out of the 90 species identified in the fossil sites, 62 species are either locally extinct and no longer found on that particular island or globally extinct. Species losses were distributed across habitats and feeding types, including insectivores and scavengers, though relatively more species were lost from the pine and broadleaf forests during the period of rising sea levels and the transition from the Pleistocene to the Holocene. According to the authors, the factors that likely fueled these extinctions, including increasing hurricane severity and human expansion, are currently in play, leaving bird populations at risk.
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Article #20-13368: "Bird populations and species lost to Late Quaternary environmental change and human impact in the Bahamas," by David W. Steadman and Janet Franklin
MEDIA CONTACT: Janet Franklin, University of California, Riverside, CA; tel: 951-827-4619; e-mail: <janet.franklin@ucr.edu>
Journal
Proceedings of the National Academy of Sciences