They also provided over wintering for the monarch butterfly. It is also well known as a hotspot to see monarch butterfly migrations. Crowell is on the migration path of the monarch butterfly. Topoclimate and microclimate in the Monarch Butterfly Biosphere Reserve (Mexico). It is one of the few birds that can safely eat the poisonous monarch butterfly. Valle de Bravo also lies in the wintering grounds of the monarch butterfly. "Gomphocarpus physocarpus" is a food of the caterpillars of "Danaus" butterflies, including the monarch butterfly. Part of Mazahua territory is in the Monarch Butterfly Biosphere Reserve. "Pteromalus cassotis" is a parasitoid of the monarch butterfly. The squash is also used as an alternative diet for Monarch butterfly caterpillars alongside cucumbers. The refuge is also a stopping point for the yearly monarch butterfly migration. The migration of the Monarch butterfly is documented and studied during annual butterfly counts. Hiking trails pass through the Moore Creek estuary and the Monarch Butterfly Nature Preserve. The onset of the rainy season signals the departure of the monarch butterfly from Mexico. The flowers of "Cosmos bipinnatus" attract birds and butterflies, including the monarch butterfly.