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    Author(s): J.D. WolfeC.J. Ralph
    Date: 2009
    Source: The Auk 126(4): 809-814
    Publication Series: Scientific Journal (JRNL)
    PDF: View PDF  (222.36 KB)


    Climatic changes induced by the El Niño–Southern Oscillation (ENSO) commonly influence biological systems; however, climatic variability and multitrophic interactions within tropical latitudes remain poorly understood. We examined relationships between migrant condition and ENSO during spring migration in Costa Rica. Our study is based on correlating an ENSO index with body-condition metrics of six Nearctic–Neotropic migrant bird species during stopover in Costa Rica over a 10-year period. This study is the first to report correlations between El Niño and changes in condition of multiple migrant species. The condition of one insectivore improved, whereas two frugivores experienced reduced condition during El Niño. Our detected correlations suggest that the ENSO cycle may influence changes in migrant mass; such interactions may ultimately affect demographics of certain frugivorous and insectivorous migrant species. Potential future management considerations are discussed in light of global climate change and our findings.

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    Wolfe, J.D.; Ralph, C.J. 2009. Correlations between El Niño Southern Oscillation and changes in Nearctic-Neotropic migrant condition in Central America. The Auk. 126:809-814.


    condition index, Costa Rica, El Niño–Southern Oscillation, ENSO, spring migration

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