Butterfly Watching   Attractions and Recreation Directory

Monarch Butterflies of Pacific Grove

Witness the over wintering phenomenon of thousands of Monarch butterflies clustering together
pines and eucalyptus on a few select acres in Pacific Grove. Each year, beginning in late-October, when the Monarch return to spend the winter in "Butterfly Town, U.S.A.", tourists and residents visit Pacific Grove's Butterfly Trees to see the spectacle of clustering Monarchs. On the second Saturday of every October, the Pacific Grove School District holds the annual "Butterfly Parade." For this popular event, the children and their teachers dress in costumes and parade through town to celebrate the return of the Monarch.

Where do they come from? The Monarch butterfly (Danaus plexippus) is a widespread tropical
insect that ranges as far north as Canada. It cannot withstand freezing winter temperatures.
To survive, the Monarch migrates to safe over-wintering sites that are neither cold enough to
kill it, nor so warm that it wastes precious energy flying too much.
 

Monarchs east of the Rocky Mountains spend the winters in high mountains in central Mexico.
Monarchs west of the Rockies come to Pacific Grove and several other locations on the central
California coast. En route, they may travel as far as 2,000 miles, covering perhaps a hundred
miles a day, and fly as high as 10,000 feet. A mighty achievement for a creature much smaller
and more fragile than the tiniest bird!

Why is this migration so unique? In many species such as birds and whales, the same individuals travel the same routes year after year; however, the Monarchs that migrate to Pacific Grove have never been here before. In fact, several generations of Monarchs have lived and died since last year's butterflies were here.

How do they find their way? Scientists think they may rely on the Earth's magnetic field, the
position of the sun, and the polarization of the sun's rays. The butterflies have nothing but
instinct to guide them.

Butterfly Etiquette

1. Stay on designated paths and be careful of butterflies on the ground.
2. Do not disturb butterfly clusters.
3. Please don't take firewood, or remove insects, plants, or animals from their natural habitat.
4. Picnic only in designated areas, and dispose of all litter in proper receptacles.

Monarchs in Peril

The magic and mystery of the Monarch migration has charmed and captivated Pacific Grove residents and visitors for many years. Unfortunately, the phenomenon of the annual Monarch migration is endangered. The eastern population is being severely impacted by deforestation in its Mexican over wintering grounds and the western Monarchs are being squeezed by the constant pressures of coastal development and dwindling open space.

For additional information contact the Pacific Grove Museum of Natural History at (831) 648-5716
or visit www.pgmuseum.org