"As human populations and resource consumption increase across the New World, it will be  increasingly difficult to maintain most bird populations as we have known them in recent decades. Even an optimal system of parks and reserves across the New World may not protect all species. To attempt to save species that respond negatively to land-use change, we need to develop systems of monitoring population abundance and demography throughout the New World so that species with declining trends can be identified early enough in the process that focused research can determine the causes of these declines and management responses can be developed and implemented. Harder yet will be making decisions about which species we can no longer sustain in future landscapes due to a species’ inability to cope with climate and concomitant environmental
change."

John Faaborg, Richard T. Holmes, Angela D. Anders, Keith L. Bildstein, Katie M. Dugger, Sidney A. Gauthreaux Jr., Patricia Heglund, Keith A. Hobson, Alex E. Jahn, Douglas H. Johnson, Steven C. Latta, Douglas J. Levey, Peter P. Marra, Christopher L. Merkord, Erica Nol, Stephen I. Rothstein, Thomas W. Sherry, T. Scott Sillett, Frank R. Thompson III, and Nils Warnock 2010. Conserving migratory land birds in the New World: Do we know enough? Ecological Applications 20:398–418. http://dx.doi.org/10.1890/09-0397.1