An Examination of Interannual Population Variation in Parnassius Clodius Butterflies

Abstract

Examining how population size and structure vary over time is an important part of understanding how environmental factors influence a particular species. Organisms in which multiple generations can be studied in a short period of time are useful when attempting to predict the consequences of such changes. Insects, and in particular butterflies, have a short generation time, which makes them ideal for studying the effects of environmental change on demographics. In this study, we examine the population dynamics of a butterfly common in the Teton area, Clodius Parnassian (Parnassius clodius). This area was initially studied starting in 1998-2000 (Auckland et al. 2004) and surveys were continued in 2009 – 2011. Emergence date varied between years by as much as three weeks. In addition, peak flight and end of flight dates also varied. Preliminary examination of the population data reveals similar patterns across years, where male emergence occurred prior to female emergence. In addition, sex ratios were also fairly consistent between years. Variation among years is observed primarily in the total number of butterflies marked and recaptured. Further data analyses comparing demographic parameters such as survival and population size need to be performed before any additional conclusions can be made. This study will add additional data to an ongoing study of the potential effects of environmental change on a common species of butterfly (Parnassius clodius).