As adults, some butterflies can feed on a variety of nectar plants and are considered generalists, while other species feed on or show preferences for a limited number of food sources. In butterfly houses, butterflies provisioned with sufficient nectar are expected to live longer and have better health. The Montreal Insectarium Grand Vivarium (MIGV) was used as an experimental macrocosm to study the feeding preferences of 21 butterfly species. We ask the question ‘Do the butterflies of the MIGV show feeding preferences?’ We measured niche breadth in terms of feeding and explored associations between butterfly species and natural and artificial nectar sources. Our results show that some butterflies in the MIGV are generalists, visiting up to eight plant species, while others feed only on one or a few. On the other hand, no plant species was visited by all butterfly species. Some flowers were visited by up to 12 species of butterflies, while others by only a few. Some heliconiine species displayed feeding behavior known to occur in the wild. Together, these results contribute to a better understanding of butterfly ecology in controlled environments and highlight the importance of diverse nectar resources for butterfly welfare in museum settings.