Data Sources


  • Lincoln P. Brower, Sweet Briar College, Sweet Briar, VA
  • Dan Slayback, Science Systems and Applications, Inc., Greenbelt, MD


  • Slayback et al. “Establishing the Presence and Absence of Overwintering Colonies of the Monarch Butterfly in Mexico by the Use of Small Aircraft.” American Entomologist (Spring 2007).

Data and Images 

  • North America, March 2004 (Blue Marble: Next Generation; satellite: NASA Terra/Aqua, sensor: MODIS)
  • Central Mexico, 21 March 2000 and January 16, 2003 (mosaic) (Global Land Cover Facilitysatellite: NASA Landsat 7, sensor: ETM+)
  • Lomas de Aparicio, March 22, 2004 and February 23, 2008 (IKONOS satellite image courtesy of GeoEye;
  • Clustering monarchs (University of Kansas)
  • Migrating monarchs (Lincoln Brower)
  • Monarch colony/oyamel forest/protected area data (courtesy of Dan Slayback)