Phenology Curves and Histograms: These graphs show how the abundance of butterflies varies throughout the year, and also from year to year, at a particular location. For migratory species such as Vanessa atalanta or V. cardui, comparing diagrams from different locations along a presumed migratory track may provide clues to understanding how butterflies move during the year. The degree of year-to-year variation in a butterfly population is also important. According to Pollard and Yates (1993), regular yearly peaks of similar amplitude, such as are found in the Red Admiral (V. atalanta), characterize seasonal migrators. Strong variation in yearly abundance is characteristic of species such as the Painted Lady (V. cardui) which sporadically emerge in large outbreaks typically several years apart.
Phenology Curves and Histograms
This page was updated on February 22, 2002.