The annual migration of Monarch butterflies east of the Rocky Mountains is well-documented. Perhaps it is because of the distance they travel to the Oyamel Fir Forests in central Mexico…
The Monarchs WEST of the Rockies, however, migrate to the coast of California. (Wouldn't you want to go to the beach during the winter, too?)
Note: Interestingly, studies have been conducted as to whether or not there are differences between the 'West Coast' and 'East Coast' versions of this beautiful creature. No genetic differences have been found, yet, breeders and scientists prefer that the two are not mixed.
Each fall, beginning in October, the Monarchs in the United States begin to migrate. Those east of the Rockies fly south towards Mexico and those west of the Rockies fly west towards the coast of California. Those butterflies in the Baja area fly northward, along the coast, to the various California overwintering sites.
The West Coast Monarchs do not gather in the numbers like those seen in Mexico. They don't gather in one place, either. Instead, there are areas where Eucalyptus and Pine trees grow together, providing shelter from wind. These sheltered areas are where the Monarchs gather together to 'overwinter.' They live in the Eucalyptus and Pine groves until February. During this time, they do not mate. They may flutter about while the sun is out and the temperature is warm. At the end of February, they begin to fly back towards their 'homes,' mating along the way and ovipositing on the Milkweed along the route.Sadly, in California, rapid growth has caused some of the overwintering sites to be razed for development. Milkweed is also scarce, which means places for these beauties to oviposit (lay their eggs) and their caterpillars to grow is becoming a rarity. Keeping the current California overwintering sites open as preserves will allow these natural wonders to continue their annual trek. Now, we all need to step up and provide them with the Milkweed to sustain their offspring.
Special Note: These pictures were taken in December 2007 in Santa Barbara, California