We’re not 100% sure what species of swallowtail these individuals are, but we’ve narrowed the possibilities down to the Two-tailed Swallowtail (Papilio multicaudata) and the Western Tiger Swallowtail (Papilio rutulus). We’ve read that the “The best clue [for the Two-tailed] is the black edge of the pupil of the large eye spot, which is a thin line. In Western it should be a thick border.” (David J. Ferguson, Contributing Editor for BugGuide). What do you think? Both are among our largest and arguably most spectacular butterflies, sporting bold black and yellow wings. 

Photo by: Jenah Mead on 8/2/21 in Missoula, MT

Photos by: Randy Zielinski on 8/11/21 in Missoula, MT