Monarch butterfly

The monarch (Danaus plexippus) is a large nymphalid with a wingspan of 8.9–10.2 cm, orange above with black veins and margins. Larvae are oligophagous on milkweeds, storing cardenolides that make them distasteful; adults take nectar. Eastern North American butterflies migrate up to 4,000–4,800 km to fir forests in Michoacan and the State of Mexico at 2,400–3,600 m, the migratory generation living seven to nine months. The IUCN assessed the species as Least Concern in 2022 and, in a 2023 revision, the migratory subspecies as Vulnerable, after Mexican overwintering area fell from 18.2 to 0.9 hectares.