I was also surprised when reading another butterfly book that asserted the lesser frit taxa butleri and grandis are "habitat forms"; claiming butleri as a tundra bug and grandis as a forest bug. That is misleading because butleri is NOT limited to tundra habitats in Alaska and Yukon. Note that the butleri specimen I illustrated yesterday is from a forest population. And grandis is not limited to forest habitat. These sympatric and synchronic (flying together) Yukon specimens were not in forest habitat: https://flic.kr/p/PnHzLo