What do monarchs feed on in winter? Nectar sources at hibernation sites

Monarch butterflies, despite long-held beliefs, actively feed on nectar during their overwintering period in Mexico’s Monarch Butterfly Biosphere Reserve. A systematic study identified 29 plant species—primarily white, yellow, or blue-flowered and winter-blooming—as key nectar sources, with Salvia mexicana and S. plurispicata being the most visited. Individual plants like Prunus serotina and Crataegus mexicana also attracted significant attention. These findings suggest that promoting such species in agricultural areas could support monarch conservation by mitigating reserve decline in disturbed forests.

Sánchez-Tlacuahuac, N., Pimentel-Equihua, J. L., Espinosa-Hernández, V., & Vibrans, H. (2022). What do monarchs feed on in winter? Nectar sources at hibernation sites. Journal of Insect Conservation, 27(1), 181–191. https://doi.org/10.1007/s10841-022-00433-z