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Pleistocene History of Amazonian Birds as Reconstructed by Ecological Niche Modeling

Pleistocene History of Amazonian Birds as Reconstructed by Ecological Niche Modeling. Amazon areas of endemism. Amazon areas of endemism. Riverine barrier hypothesis (past and present). Marine transgression hypothesis. Pleistocene climatic fluctuations.

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Pleistocene History of Amazonian Birds as Reconstructed by Ecological Niche Modeling

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  1. Pleistocene History of Amazonian Birds as Reconstructed by Ecological Niche Modeling

  2. Amazon areas of endemism

  3. Amazon areas of endemism Riverine barrier hypothesis (past and present) Marine transgression hypothesis Pleistocene climatic fluctuations

  4. Testing Pleistocene hypothesis in a snap shot... 21,000 before present (at last glacial maximum-LGM) Predictions: Reduction and fragmentation in the potential distributions of forest environments Expansion in the potential distributions of savanna environments

  5. Data Set Forest species Campephilus rubricollis Formicarius colma Phylidor pyrrhodes Automolus infuscatus Pipra coronata Tangara mexicana Rauvolfia parensis R. polyphylla R. sprucei

  6. Data Set Savanna species Athene cunicularia Sublegatus modestus Sporophila plumbea Emberizoides herbicola Ammodramus humeralis Rauvolfia weddelliana R. ligustrina Curatella americana

  7. Data Set Aspect Slope Topographic Index Topographic Layers1 Present2 Temperature Precipitation Climatic Layers 21,000 Years Ago3 Hadley Centre Canadian Center 1US Geological Survey (http://edcdaac.usgs.gov/gtopo30/hydro/) 2Intergovernmental Panel on Climate Change (http://www.ipcc.ch) 3Paleoclimate Modeling Intercomparison Project (http://www-lsce.cea.fr/pmip/)

  8. Ecological Niche Modeling: GARP Projection in present scenario Ecological data Projection to past scenario Collection locality data ENM GARP

  9. Implicit assumptions... Ecological niches are relatively stable in evolutionary time (see Dr. Martinez-Meyer’s several publications) The paleoclimate reconstructions are fair approximations of past climatic conditions

  10. Forest species: an example Tangara mexicana Occurrence points

  11. Forest species: an example Tangara mexicana Present Potential Distribution Low model agreement (= ‘absence’) High model agreement (= ‘presence’)

  12. Forest species: an example Tangara mexicana Potential Distribution Present Hadley Scenario (21,000 yrs ago)

  13. Forest species: an example Tangara mexicana Potential Distribution Present Hadley Scenario (21,000 yrs ago) Canadian Scenario (21,000 yrs ago)

  14. Forest species: More examples

  15. Forest: All Species Potential Distribution 21,000 Years Ago Hadley and Canadian averaged

  16. Savanna: All Species Potential Distribution 21,000 Years Ago Hadley and Canadian averaged

  17. Main conclusions • Potential distribution of forest birds contracted and fragmented during the last glacial maximum • • Some peripheral areas of the Amazon retained suitable • conditions for these species during the LGM • (being these areas coincident across species) • • Potential distribution of savanna birds did not show a • consistent pattern during the same period.

  18. Limitations and Next Steps • More species, more localities Use molecular data to test explicit hypotheses in a phylogenetic framework • Broaden study in terms of taxa included, and species from communities now peripheral to the Basin (dry-forest arches, Andean, Tepuian species, etc.) • Enrich the suite of climate scenarios and use higher resolution coverages

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