Danaus plexippus
Welcome to Art's Butterfly World

Monitoring butterfly populations across central California

Art Shapiro at Rancho Cordova Site

Explore California Butterflies with Dr. Art Shapiro

This website describes over 45 years of data collected by Dr. Arthur Shapiro, professor of Evolution and Ecology at the University of California, Davis, in his continuing effort to regularly monitor butterfly population trends on a transect across central California. Ranging from the Sacramento River delta, through the Sacramento Valley and Sierra Nevada mountains, to the high desert of the western Great Basin, fixed routes at ten sites have been surveyed at approximately two-week intervals since as early as 1972.  Data is available at these sites upon request.  The sites represent the great biological, geological, and climatological diversity of central California.