Papilionidae, Pieridae, Lycaenidae, and Nymphalidae. Close to 750 species inhabit the United States and Canada, most notably the Monarch and Regal Fritillary can be found in Nebraska. Approximately 3% of butterfly species are threatened with extinction. This decline in butterfly populations is attributed primarily to habitat loss due to urbanization and agriculture. As populations continue to decrease, a growing need to closely monitor species is developing. Because there is little distinction between some types of butterflies, identification and classification proves to be a challenge. Very few Lepidopterists (scientists who study butterflies and moths) exist; therefore monitoring population sizes and ranges of butterfly species is a daunting task.