Abstract
An adult population of a papilionid butterfly, Luehdorfia japonica Leech was studied by marking, release and recapture procedures in a hilly region of Matsunoyama Town, Niigata Prefecture. Thirty-two males and 15 females were marked and released, and 13 males and one female were recaptured at least once. Daily survival rate estimated by Jolly-Seber method was 0.75, and that estimated by recapture duration decay plotting was 0.81, respectively. Estimated total population size per generation was 39.7 by Jolly-Seber method, but this could be an underestimation. The total population size derived from a new method developed from recapture duration decay plotting was 68.4.In comparison with a high density population of the same species studied earlier, the low density population studied here was different in that the butterflies were mostly found solitary and patchy structure of the population was unclear, and although the males mostly flew around in search for females, sometimes they exhibited hilltopping with perching behaviour on some summits or patrolling behaviour on summits and ridges.
