2006 Volume 10 Issue 1-2 Pages 61-71
Parnassius eversmanni daisetsuzanus is on the Japanese Red List (Near Threatened) and considered a special natural monument in Japan. To elucidate the yearly population changes of this species, transect surveys were carried out on Komakusa-daira mountain (1,840m) in Daisetsuzan National Park, Hokkaido, Japan over six years (2000-2005). The transect route (280 m) was fixed along a mountain trail, and the surveys were carried out hourly from 06:00 to 13:00. The yearly maximum counts were 5 (2000), 9 (2001), 7 (2002), 18 (2003), 22 (2004) and 24 (2005). The results suggest that the population density of P. e. daisetsuzanus has been on an increasing trend in recent years in this area. The study also examined hourly flight activity, indicating that it peaks between 10:00 and 11:00.
