Clouds of monarch butterflies have returned to winter on , after more than a decade of extremely low populations.
On Saturday, more than 1,400 monarchs were seen on the hill, said Bill Shepard, the volunteer counter for Albany's monarch population. The weekend before he counted 500.
"That's the most I've ever seen here," in 10 years of watching the butterflies on Albany Hill, Shepard said.
Last Tuesday at noon, dozens of large, orange-and-black butterflies drifted in the air, while 100 or more clustered on one tree near the hill's main path. Fifty yards away, another 200, at least, lined the branches of a very small eucalyptus, like ornaments on a Christmas tree. By Wednesday afternoon, both groups seemed to have consolidated in two adjacent trees on a steep, hard-to-access slope.
In the photos here, none shows more than 10 percent of the butterflies clustered on Wednesday. Photographer Doug Donaldson used a large, 300-mm telephoto lens to catch the monarchs high overhead. Butterfly-watchers should bring binoculars, and watch out for the poison oak, which is prevalent in the area.
The resurgence of the monarchs isn't just here in Albany.
"I think that numbers, so far, are up all over California," said Scott Black, executive director of the Xerces Society, which tracks 80 or more wintering sites in the state. Current reports are preliminary; the official count takes place at Thanksgiving, but Black called himself "cautiously optimistic" after years of bad news in the monarch world.
"From '97 to last year, we saw well over a 90 percent decline in monarch populations in the west," Black said. At Albany Hill, in 1997, 3,000 monarchs were counted; the number plunged the next year to 85 and after that exceeded 100 only once.
One possible reason for the increase, Black said, is that the end of the drought has allowed milkweed, the plant on which monarchs lay their eggs, to thrive. Although this year's early numbers are encouraging, Black cautions that populations will not likely be anywhere near as high as in the 1980s and early '90s, when some sites had more than 100,000 monarchs.
Part of the excitement over monarchs is that they are one of only two insects in the world that make a true annual migration. They travel up to 3,000 miles every winter to warmer climates.
During the summer, monarchs live throughout the United States and southern Canada. Come fall, the monarchs east of the Rockies make their way to Mexico, where they gather by the millions in the Michoacan region.
Monarchs west of the Rockies head mainly to coastal California sites, the largest of those being from Santa Barbara north to Monterey. Monarch sites in Pacific Grove and near Santa Cruz attract some of the biggest populations in Northern California, but the Bay Area is home to a dozen or more small sites, from Fremont to Point Pinole in the East Bay, and along the Peninsula and Marin coastlines.
When the monarchs arrive at their wintering site -- amazingly often the same site their ancestors used in years past (no one knows yet how they do it) -- they cluster together in trees that provide protection against winter storms.
Scientists believe that, historically, monarchs roosted mainly in Monterey pines and cypress, but they have adapted to the non-native eucalyptus, whose winter blossoms offer food.
On Albany Hill, as elsewhere in the Bay Area, the butterflies start arriving at their winter sites in October, with their numbers increasing until late November or early December. Those that survive winter storms disperse around January to repopulate inland regions. (Some, of course, remain fairly local.)
One can hope that Albany's monarch population will continue to increase in the coming two to three weeks. However, sometimes a small colony, such as Albany's, can depart mid-winter for another site.
It's best to visit the hill on a clear day to see the butterflies when their orange wings are open. Monarchs can't fly until their bodies are heated by the sun, so on cloudy days they cluster on the trees, wings folded up, revealing their tan undersides, which are hard to see from a distance.
Finding the butterflies can be a challenge, as they can change trees, following the sunlight. Here are a few spots to check:
- If you park at the top of Taft Avenue, take the wide trail south by the "Albany Hill Park" sign, about 100 yards. After you pass a bench and tree swing, the path starts to descend and gets rocky -- watch your step. Pass the white cross and continue about 30 paces. The monarch tree will be on your right (west of the trail), and it has a double trunk. The butterflies would be on the sunny, south-facing, lower branches, about 15 to 20 feet overhead.
- For the second location, go back to the swing and bench at the top of the hill. From the swing, there is a very narrow path through the grass, headed south. Follow it to the next large tree with a swing. Stop there; the path gets very steep and slippery with leaves after this. Just downhill is another tree hung with ropes. Look just to the right of it, and about 20 to 30 feet further downhill. If it's sunny, you may see quite a few butterflies in the air. Look for a very small eucalyptus. If you have binoculars you may see butterflies on its branches.
- On Wednesday afternoon, the butterflies had moved a short distance from the small tree onto some west-facing branches, not visible from the swing area. The path to see them is extremely steep. There is another, very narrow, path to access that area, which starts across the main path from the cross, but it is difficult to find and somewhat uneven.
Even if you can't find the large clusters of monarchs, on a sunny day you are likely to see several dozen floating through the air on the the hilltop.
Here are some other monarch wintering sites you can visit:
- City of San Leandro: Naturalist-led walks for all ages at the Monarch Bay Golf Club (west of I-880). 5,000 monarchs reported as of Nov. 8. See the 9/26/11 PDF at http://www.sanleandro.org/services/press.asp. Contact email@example.com or 510-577-3462.
- Ardenwood Historic Farm, Fremont: Guided walks and special programs weekends. Entry fee. 2,700 monarchs reported as of Nov. 5. On the web at http://www.ebparks.org/node/1579. Call 510-544-2797.
- Natural Bridges State Park, near Santa Cruz. http://www.thatsmypark.org/cp-parks-beaches/natural-bridges-state-park
- Pacific Grove, Monterey Peninsula: 6,600 monarchs as of Oct. 29. www.pgmuseum.org/category/topics-interest/butterflies
The monarch butterfly's life cycle, from egg to caterpillar to chrysalis to butterfly is a whole other fascinating story. Learn more here.
An excellent photo exhibit of the life cycle is available on El Cerrito Patch blogger Heidi Rand's site. See "Life cycle of the monarch butterfly."
For more information on monarchs see http://www.xerces.org/monarchs.