Monarch Butterflies: Our Fluttery Friends Are Wintering In The Area

BAY AREA, CA — Monarch butterflies are a delightful perk of living in the San Francisco Bay Area. Their ethereal beauty is reminiscent of a floating flower. Each year their numbers swell in the wintertime — most notably from November to February — as they flock to California from Canada and U.S. states west of the Rocky Mountains. Those east of the Rockies migrate to Mexico.

The butterflies have selected several places to congregate in the East Bay including Alameda, San Leandro and Fremont. There is also a small group of monarch butterfly groves, where visitors can view thousands of butterflies clustered in trees. The closest is Natural Bridges State Beach in Santa Cruz, the only state monarch preserve in California. There’s also Monarch Grove Sanctuary in Monterey County’s Pacific Grove. Farther south, there are monarch groves in Pismo Beach and Goleta. The Pacific Grove Museum of Natural History reports the butterflies do not typically venture farther than Central California to conserve their energy.

The museum notes butterflies "may travel as far as 2,000 miles, covering one hundred miles per day, and flying as high as 10,000 feet. A mighty achievement for such a seemingly fragile insect!" Weekly counts of monarchs are updated online during the overwintering season, with the most recent count of 8,336. Local residents even tax themselves to maintain the monarch sanctuary.

But you don’t have to travel to Santa Cruz or Pacific Grove to see monarch butterflies — you may spot them flitting around your own backyard or in smaller clusters in parks. The butterflies are especially fond of eucalyptus trees, which flower during the winter providing monarchs with a source of food.

Monarchs have chosen a city park in Alameda to congregate this winter. Eliya Selhub took the featured photo above at Lincoln Park.

"Our neighbor mentioned the monarchs so we came to see them," Selhub told Patch. "They look like leaves with their wings closed, so I wasn’t able to spot them until someone else pointed them out. I had my camera set up on a tripod with a long lens, so it was easier for people to see them in the viewfinder. They stayed clustered in the tree until the sunlight hit them, and then they took off."

Selhub dropped a pin where he photographed the butterflies.

In San Leandro, thousands of monarchs migrate annually to a grove at the City’s 9-hole executive golf course. Monarch Butterfly Naturalist Adrienne De Ponte periodically leads free public tours of the grove which may be scheduled through the recreation department. A study of the grove including a butterfly count is currently underway which will guide future conservation efforts.

Hundreds of monarchs have chosen Ardenwood Historic Farm in Fremont, part of the East Bay Regional Park District, to overwinter. This marked the first winter in three years the butterflies were spotted at the farm. The Park District described the butterflies online, "Look for the monarchs in the eucalyptus grove near Deer Park along the train tracks. On cool days they hang motionless high in the trees and can easily be mistaken for a clump of dead leaves. Add some sunshine, though, and the clump transforms into a bright orange fluttering mass as they open their wings to soak up the warmth. When the monarchs are warm enough to fly, they head out to search for nectar from nearby flowers."

In July, the International Union for Conservation of Nature (IUCN) labeled migratory monarch butterflies endangered. The organization said the butterfly is threatened by habitat destruction and climate change, adding it to the Red List of Threatened Species.

Attract Monarch Butterflies To Your Backyard

There are many fine articles available online that suggest ways to attract butterflies to your backyard. The National Wildlife Federation provides this information:

• Plant native flowering plants - The favorite flower of monarch butterflies is milkweed. This blooms in the summertime in the Bay Area so it is not available to overwintering butterflies. However, it is useful to have in the garden to draw monarchs that spend the summer here.
• Plant type and color are important - Adult butterflies are attracted to red, yellow, orange, pink and purple blossoms that are flat-topped or clustered and have short flower tubes.
• Plant good nectar sources in the sun - Your key butterfly nectar source plants should receive full sun from mid-morning to mid-afternoon. Butterfly adults generally feed only in the sun.
• Plant for continuous bloom - Butterflies need nectar throughout the adult phase of their life span. Try to plant so that when one plant stops blooming, another begins.
• Say no to insecticides - Insecticides such as malathion, Sevin and diazinon are marketed to kill insects. Don't use these materials in or near the butterfly garden or anywhere else on your property. Even "benign" insecticides, such as Bacillus thuringiensis, are lethal to butterflies (while they are caterpillars).
• Feed butterfly caterpillars - If you don't "grow" caterpillars, there will be no adults. Bringing caterpillar foods into your garden can greatly increase your chances of attracting unusual and uncommon butterflies, giving you yet another reason to plant an increasing variety of native plants.
• Provide a place for butterflies to rest - Butterflies need sun for orientation and to warm their wings for flight. Place flat stones in your garden to provide space for butterflies to rest and bask in the sun.
• Give them a place for puddling - Butterflies often congregate on wet sand and mud to partake in "puddling," which is drinking water and extracting minerals from damp puddles. Place coarse sand in a shallow pan, then insert the pan in the soil of your habitat. Make sure to keep the sand moist.