|Monarchs on Frostweed in butterfly Garden, by Bill Powell|
Monarch butterflies are taking center stage at Hagerman National Wildlife Refuge these days as large numbers are seen nectaring, "fattening" up as they journey to Mexico for the winter. Photographers are having a field day in the Butterfly Garden, which is living up to its designation as a Monarch Waystation, finding monarchs galore on the Frostweed and Baccharis planted there and blooming just in time for the migration. North American monarchs are the only butterflies that make such a journey, which the World Wildlife Federation describes as:
... a marvelous migratory phenomenon. They travel between 1,200 and 2,800 miles or more from the United States and Canada to central Mexican forests. There the butterflies hibernate in the mountain forests, where a less extreme climate provides them a better chance to survive.Also from WWF,
The monarch butterfly is known by scientists as Danaus plexippus, which in Greek literally means "sleepy transformation." The name evokes the species' ability to hibernate and metamorphize.From National Geographic:
Butterflies that emerge from chrysalides (pupa state) in late summer and early fall are different from those that do so during the longer days and warmer weather of summer. These monarchs are born to fly, and know because of the changing weather that they must prepare for their lengthy journey.
Only monarchs born in late summer or early fall make the migration, and they make only one round trip. By the time next year's winter migration begins, several summer generations will have lived and died and it will be last year's migrators' great grandchildren that make the trip. Yet somehow these new generations know the way, and follow the same routes their ancestors took—sometimes even returning to the same tree.
Many scientists are concerned about the eastern population of monarchs, which summer east of the Rocky Mountains. This group is occurring in ever smaller numbers, and its survival may be threatened by a series of natural disasters in the Mexican wintering grounds, as well as by reduced acreage of milkweed plants in their summer home.